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THE INTRAUTERINE CONTRACEPTIVE DEVICE
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UPDATE IN CONTRACEPTION
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0889-8545/00 $15.00
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THE INTRAUTERINE CONTRACEPTIVE DEVICE Anita L. Nelson, MD
Before its introduction into the United States in 1988, the copper intrauterine device (IUD) was carefully tested following the Food and Drug Administration (FDA) regulations for new drugs. The Centers for Disease Control and Prevention (CDC) closely monitored postintroduction events for currently available IUDs for nearly a decade before concluding that IUDs were safe and effective methods of birth contr01.~ Because IUDs dramatically reduce the risk of unintended pregnancy and are convenient, rapidly reversible, and cost-effective, it is remarkable that this method is so infrequently used in the United States. Less than 1% of married contracepting women in the United States use IUDs. Worldwide, the IUD is the most frequently used method of reversible contraception; 106 million women (10% of married women of reproductive age) were using IUDs for birth control in 1995.4OIn Western Europe, rates range from 7% to 19%. Many US physicians are reluctant to recommend the IUD to their patients because of the negative clinical experience and medicolegal nightmares that resulted from flaws in the Dalkon Shield and earlier misapplications of the IUD. Nevertheless, the dissemination of new scientific evidence and recent clinical experience support greater use of IUDs in the United States.
From the Department of Obstetrics and Gynecology, University of California Los Angeles School of Medicine, Los Angeles; and Women’s Health Care Programs, HarborUniversity of California Los Angeles Medical Center, Torrance, California
OBSTETRICS AND GYNECOLOGY CLINICS OF NORTH AMERICA VOLUME 27 * NUMBER 4 * DECEMBER 2000
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HISTORICAL OVERVIEW Early International Intrauterine Devices
The first IUDs for women were developed in nineteenth-century Germany as variations of vaginal pessaries. These early IUDs were rigid metal appliances that extended from the vagina or the ectocervix through the cervical canal into the endometrium.1sThey were multipurpose devices that only indirectly acted as contraceptive^.^^ In 1902 Hollweg introduced a self-inserted pessary that extended into the uterus and that was intended explicitly for contraception. In 1909 Richter31 introduced a silkworm-catgut ring with a nickel and bronze wire protruding through the cervical 0s. Although there is no written record of how the male partner responded to this metal protrusion at the top of the vaginal vault, PusPo rapidly replaced the metal wire with catgut thread and added features of the old button-type pessary. Given that these devices were used by women in the days before antibiotics or nonsteroidal antiinflammatory drugs (NSAIDs), their use quickly became associated with serious infections and significant patient discomfort. These side effects created such an enduring negative image for IUDs that when Grafenberg introduced the first true IUD in the 1920s, it was generally rejected by the medical community. The Grafenberg ring was a tailless device composed of “German silver” an alloy of copper, nickel, and zinc.16 Because of its extreme flexibility, expulsion could easily remain undetected, exposing the user to unwanted pregnancy. The Ota ring was introduced in Japan in 1934 to correct that problem; it added a small central disk with three spokes that radiated out to the inner surface of the gold or gold-plated ring to stabilize the device and reduce expulsion.28Throughout World War I1 and the postwar baby-boom years, IUDs were in general use only in Israel and Japan. In 1959 a landmark issue of the American Journal of Obstetrics and Gynecology, in which Ishihama and Oppenheimer reported their clinical experience with IUDs, inspired worldwide interest in these devices and triggered an outpouring of creative new designs.21,27 Early Intrauterine Devices
Although several investigators continued to create metal wire devices, most of the successful new IUDs were based on polyurethane frames embedded with barium sulfate to make them visible on radiographs. Within a decade, several plastic devices, such as the S-shaped Lippes Loop, the Tatum T, and the Safe-T-Coil, were in widespread use. In 1969, Zipper reported that copper had a profound impact on the When Tatum wrapped a thin copper wire around the stem of his plastic IUD to create the Copper T200, the first-year typical failure rates decreased to 1.5% to 2%. In 1971 the Copper 7 IUD was introduced and found favor with physicians for use in nulliparous
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adolescent women who had difficulty successfully using oral contraceptive pills. In the late 1960s, investigators at John Hopkins developed the Dalkon Shield-an all-plastic device with small plastic protrusions around its edges to help it adhere to the endometrium and reduce the risk of expulsion. Clinical trials conducted following the FDA regulations for devices (not drugs) revealed that the first-year failure rate was 1%-lower than the rate for any IUD available at the time. Early in product development, it was discovered that the original tail strings tended to break during attempted IUD removal. Unfortunately, these strings were replaced by a sheathed polyfilament string. When the strings were cut, the sheath was compromised. Bacterial pathogens could enter the hundreds of small interfilament interstices within the tail string and, by wicking or capillary action, travel through the cervix protected from its mucous defense systems. In about 25% of the units, the protective sheath was also broken at the knot at the base of the unit, which allowed the pathogens an exit pathway into the vulnerable endometrial cavity. This unique design flaw accounted for the significant incidence of pelvic inflammatory disease (PID) and its sequela sustained by Dalkon Shield users. When cultures were taken of the tail strings of the Dalkon Shield aerobic organisms were found on 42% of the strings and anaerobes on 86% of the strings.39All currently used IUDs are fitted with monofilament tails, which are consistently sterile when cultured. Direct comparison studiesz9 and meta-analysis'* have failed to find any increased risk of PID for women using IUDs with monofilament tail strings when compared with women using tailless IUDs. Lessons Learned: Infection Risks
The risk of infection with IUD use is related to the woman's underlying risk for acquiring sexually transmitted diseases (STDs). Lee and co-workersu found that among users of IUDs other than the Dalkon Shield, the risk for PID varied by relationship status. Women in ongoing relationships (cohabitating or currently married) had no statistically significant increased risk for PID when using IUDs, whereas previously married and never-married IUD users showed relative risks for PID of 1.8 and 2.6, respecti~ely.~~ Burkman4reported that the greatest risk factor for PID with IUD use was multiple sex partners. When women with one partner who had never used an IUD were used as the referent population, women who had one partner and who used a copper IUD showed no increased risk for primary tubal infertility. In contrast, women with multiple sexual partners who used IUDs showed an increased risk for tubal infertility.8,lo After correcting the design flaws of the IUD tail string and correctly identifying appropriate IUD candidates, the remaining issue for PID infection was the transient contamination of the endometrial cavity at the time of insertion. Farley and co-~orkers'~ reconfirmed Mishell's
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observationz4that PID infections with IUD use are concentrated in the 20 days following insertion. In Farley’s international study, the absolute risk for PID in that early period was about 1%.Recent studies conducted in developed countries (where patient selection and testing practices are comparable with procedures in the United States) have found that the incidence of PID is only about 1 case per 1000 insertions.35,44 TYPES OF INTRAUTERINE DEVICES AVAILABLE IN THE UNITED STATES
The copper IUD (ParaGardT 380A, Ortho-McNeil Pharmaceuticals, Raritan, NJ) is a T-shaped polyethylene device with 380 mm2of exposed surface area of copper on its arms and stem. The polyethylene frame also contains barium sulfate, which renders it radiopaque. The white polyethylene monofilament tail strings pass through and are knotted below a 3-mm plastic ball at the base of the stem. The ball helps reduce cervical perforation with expulsion. The copper IUD is approved by the FDA for up to 10 years of use, but a recent study suggests that it may be effective for at least 12 years. No pregnancies were reported before the eighth year of ~ s e . 4 ~ The progesterone-releasing IUD (Progestasert, Alza Laboratories, Palo Alto, CA; acquired by Abbott Laboratories, North Chicago, IL in 1999) is a T-shaped device made of ethylene/vinyl acetate copolymer. The frame is radiopaque. The stem contains a reservoir of 38 mg of progesterone that is released at a rate of 65 pg/day. The two arms are used only to stabilize the device. The device has two blue-black monofilament strings attached at a hole in the base of the stem. The progesterone-releasing IUD is approved for 12 months of use in the United States. Other IUDs are currently used by women living in the United States. Before 1985, tens of thousands of plastic IUDs with an unlimited life span (e.g., the Lippes Loop and Safe-T-Coils)were inserted. Some of these women plan to continue to use these IUDs until they reach menopause. In addition, many women who immigrate to this country use IUDs that have not been approved in the United States. In Europe, a levonorgestrel-releasing IUD and a frameless copper IUD have been in widespread use for several years. In the Middle East and Central and South American, women still have access to the inert plastic IUDs. In Canada, women have different copper and silver IUDs. The vast majority of immigrant IUD users come from Asia, where tailless circular IUDs are most common. EFFICACY
Because IUDs require little patient action for their continued action, the typical failure rates for IUDs closely approximate the failure rates
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associated with correct and consistent use; however, the effectiveness of the IUD varies by model. The copper IUD has a first-year failure rate of 0.7% with typical use. Nulliparous women have slightly higher failure rates (0.8%) than parous women. The copper IUD has a cumulative 10year typical failure rate of 2.1% to 2.7%, which is less than the typical first-year failure rate for oral contraceptives. The progesterone-releasing IUD has a first-year typical use failure rate of 2%. The Lippes Loop and Safe-T-Coil IUDs have a first-year failure rate of 3%, but current users of these IUDs may experience significantly lower pregnancy rates because they have successfully used their devices for so many years. Table 1 summarizes the first-year failure rates. SELECTION OF CANDIDATES
Product labeling indicates that the IUD user should be a parous woman with no history of PID who is in a stable mutually monogamous relationship. The parous woman need not have completed her childbearing but must have demonstrated her fertility. It is estimated that more than 10 million American women fit all aspects of this patient profile and have no contraindications to IUD use; however, many more millions of women may also be excellent candidates for IUD use. Nulliparity has never been a contraindication to IUD use. Although is recognized that IUD insertion through a cervix that has not been previously dilated may be slightly more challenging, many parous women who have been electively delivered by cesarean section present the same challenges. The uterine cavity of a nulliparous woman is smaller. As a result, the expulsion and failure rates are slightly higher in women who have never borne children, but the IUD still provides excellent pregnancy protection for these women. The real concern with IUD use in nulliparous women who are not at risk for STDs is not strictly medical but medicolegal. Ten percent to 15%of American couples sustain infertility problems. Placing IUDs in women with unproved fertility exposes the IUD, and potentially the provider, to the risk of charges after IUD removal that the IUD caused infertility. Careful preinsertion counseling is needed to explain potential unrecognized infertility to nulliparous patients. Table 1. FIRST-YEAR FAILURE RATES FOR THE INTRAUTERINE DEVICE (IUD) Correct and Consistent Use (%)
Typical Use
Type of IUD Progesterone IUD Copper IUD Levonorgestrel IUD*
1.5 0.6 0.1
2.0 0.8
(W 0.1
*Not FDA-approved by July 2000. Datafrom Stewart GK: Intrauterine devices (IUDs). In Hatcher RA, Trussell J, Stewart F, et a1 (eds): Contraceptive Technology, 17 ed. New York, Ardent Media, 1998, p 514.
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The recommendation that the woman considered for an IUD should never have been diagnosed with PID is too restrictive. The concerns regarding IUD use in a woman with a history of PID are that it may be a marker for an ongoing risk for STD exposure, and that the salpingitis may have reduced the patient's fertility. Clearly, a 37-year-old woman sustaining PID at age 16 years but who has been in a mutually monogamous relationship for the last 15 years with the father of her six children would be a reasonable IUD candidate. The World Health Organization (WHO) standards require that a woman with a history of PID have at least one pregnancy following her latest episode of PID before she is considered for IUD use.48 Beyond the fundamental condition that a woman be in a stable mutually monogamous relationship (putting her at low risk for STDs), there are other generic contraindications to IUD use (Table 2). Pregnancy, unexplained abnormal uterine bleeding, acute cervical or vaginal infections, evidence of cervical carcinoma, and severe immunocompromise (chemotherapy, radiotherapy, acquired immunodeficiency syndrome) are contraindications to the use of any IUD as long as the condition exists.
SELECTION OF AN INTRAUTERINE DEVICE The contraindications and side effects of each of the IUDs direct women to select one IUD over another. Currently, the first-line choice for most women seeking intermediate to long-term contraception is the Table 2. CONTRAINDICATIONS TO INTRAUTERINE DEVICES (IUDS)
General Pregnancy Acute unresolved cervicitis (current or within the last 3 months) Pelvic inflammatory disease, endometritis, or pelvic tuberculosis (current or within the last 3 months) Distorted uterine cavity Uterine or cervical carcinoma Unexplained vaginal bleeding Severe immunocompromise (e.g., acquired immunodeficiency syndrome, chemotherapy) Multiple sexual partners or partner with multiple sexual partners IUD specific Copper IUD Uterine cavity <6 or >9 cm Copper allergy Wilson's disease Severe anemia Menorrhagia Severe dysmenorrhea Progesterone-releasing IUD Uterine cavity (6 or >10 cm History of ectopic pregnancy Diabetes
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copper IUD because of its superior efficacy and prolonged duration of effect. Women with anemia, heavy menses, dysmenorrhea, or bleeding dyscrasias may benefit from using a progesterone-releasing IUD, which does not increase menstrual blood loss or cramping. The maximum uterine depth differs by device. The copper IUD can be placed in a uterus that sounds to a depth of up to 9 cm, whereas the progesteronereleasing IUD can be used in a uterus with a depth up to 10 cm. Many women with medical conditions may benefit from features of particular IUDs.26 The copper IUD has been show to reduce the risk of ectopic pregnancy significantly when compared with the risk in women using no method; therefore, women who have a history of ectopic pregnancy may be candidates for the copper IUD. The progesterone-releasing IUD has not demonstrated such protection, thus it is not appropriate for women with previous tuba1 pregnancies. Diabetic women are candidates for the copper IUD but not for the progesterone-releasing IUD.22Copper allergy and Wilson's disease (a copper storage disease) are contraindications to the use of copper-bearing IUDs. Table 2 summarizes the contraindications to IUD use. MECHANISMS OF ACTION Copper Intrauterine Devices
Misguided concerns that the IUD works as an abortifacient have seriously limited IUD use by many women and have prevented many providers from offering IUDs. The evidence is clear that the IUD does not work as a postimplantation abortifa~ient.~~ Segal and co-workersM monitored 30 women using IUDs by measuring serial beta-human chorionic gonadotropin levels for 30 months and did not observe any changes in levels.34In particular, there was no evidence of an initial rise followed by an abrupt drop in levels characteristic of pregnancy interruption. Wilcox and c o - ~ o r k e r sfound ~ ~ one episode of a transient increase in 107 IUD cycles. Moreover, the failure of uterine washings to retrieve eggs in 56 IUD users in contrast to washings yielding eggs in 4 of 115 controls undermines the hypothesis that IUDs work by creating inflammatory endometrial changes that prevent implantation.' The copper IUD is a functional spermicide; the copper ions released from the device interfere with sperm mobility and create a foreign-body reaction that results in a spermicidal endometrium. Sperm counts in the cervical mucus are significantly lower in IUD users than they are in nonusers. Oviduct counts of sperm are vanishingly small in IUD users. El-HabashiI3 and M ~ y e rand ~ ~their co-workers reported finding no sperm in the fallopian tubes of 30 women with IUDs. Microscopic studies demonstrate that the inflammatory changes in the endometrium are spermicidal. Clusters of leukocytes are seen engulfing the sperm. S a g i r ~ g l ufound ~ ~ that 2 to 16 hours after coitus, spermatozoa were
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phagocytized in the endometrial cavities of IUD users. The copper ions inhibit sperm penetration into the egg; the acrosomal enzymes needed to dissolve the zona pellucida are not activated in the presence of copper ions. These observations have been verified by clinical in vivo experience. Alvarez and co-workers' performed bilateral total salpingectomies on two groups of women who had coitus at the time of documented ovulation. When the specimens were serially sliced in search of normally dividing ova, indicating fertilization, half of the controls showed normal development of the ova, whereas none of the IUD users showed evidence of ferti1ization.l Progesterone-Releasing Intrauterine Devices The progesterone-releasingIUD is believed to work as an alternative delivery system for progestin. The main mechanism of action is to thicken the cervical mucus and render it impenetrable to sperm. There may be other effects of progesterone on the endometrium, but the levels are insufficient to affect ovulation. The plastic IUD frame also induces a foreign-body inflammation reaction that is spermicidal. INSERTION ISSUES Timing and Preparation for Insertion The IUD can be inserted anytime in a woman's cycle when she is not pregnant. White and c o - ~ o r k e r demonstrated s~~ that expulsion rates for the first three postinsertion cycles were reduced by more than 30% when insertion was delayed until the end of menses. Theoretically, the optimal time for insertion is at the time of ovulation, when the cervical canal is maximally dilated and progesterone can quiet the myometrial contractions triggered by uterine manipulation. Insertion postpartum is best delayed until the uterus is completely involuted (usually, 4-6 weeks after delivery) to reduce the risk of perforation and expulsion. Nevertheless, international work suggests that insertion immediately postpartum (10-20 minutes after delivery of the placenta) is associated with low risks of uterine perforation and expulsion and may be a reasonable alternative for women who have limited access to the medical care system.38Women who have miscarriages or other pregnancy terminations in the first trimester are candidates for immediate IUD insertion unless there is evidence of infection. IUD reinsertion can immediately follow removal of a unit for expiration, expulsion, or partial expulsion. The preparation for IUD insertion is straightforward. Women generally benefit from taking NSAIDs 1 hour before the insertion. A small amount of lidocaine injected at the tenaculum site can reduce the discomfort associated with the placement of that instrument. A small cotton swab generously soaked in 20% Hurricane lidocaine can be placed
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into the cervical canal to reduce insertional discomfort and vasovagal reactions. If the patient has significant cervical stenosis (requiring cervical dilation), a paracervica1 block may be needed. Careful cleansing of the ectocervix, the upper vagina, and the cervical canal is intended to reduce bacterial contamination with insertion. Routine prophylactic antibiotic administration is not warranted in the United States. A recent double-blind prospective study demonstrated no statistically significant difference in PID rates in women who received 500 mg of azithromycin before insertion compared with woman who received a placebo.% It was calculated that the low background rate of postinsertion infection would require enrollment of over 100,000 patients to detect any statistically significant difference. At that rate, the antibiotics would certainly not be cost-effective. A recent meta-analysis of international experience has confirmed that antibiotic prophylaxis confers little benefit.I7 The American Heart Association guidelines for patients at risk for endocarditis suggest that antibiotic prophylaxis before IUD insertion or removal is not necessary? Although patients may need time to digest all of the information included in the patient information brochure and to consider all of the relevant issues, if an informed choice is obtained, insertion can be performed on the same day. In the absence of any clinical evidence of infection and with a reassuringly normal vaginal wet mount, test specimens for cervical infection may be obtained and the IUD promptly inserted. Vaginal microscopy studies are helpful not only in ruling out the presence of leukocytes that accompany cervicitis but also in detecting trichomoniasis and bacterial vaginosis. Patients with gonorrhea or chlamydial cervicitis and perhaps those with trichomoniasis may not qualify for IUD use until they are no longer at risk for STDs. Women with bacterial vaginosis should have that condition treated before insertions because it has been shown to increase the risk of postoperative infections in women undergoing hysterectomy and to more than double the risk of post-abortion endometritis. Insertion Complications
Vasovagal reactions occur in approximately 1% of women with cervical manipulation, particularly in women with significant cervical stenosis. If a patient is known to be at increased risk for vasovagal reactions, appropriate equipment should be available for resuscitation, and a prophylactic paracervical block should be placed. When a transient vasovagal reaction develops during insertion, supportive measures are generally adequate. Severe or prolonged episodes require the removal of the inciting agent (uterine sound or IUD). Uterine perforation occurs once in every 770 to 1600 insertions. The copper IUD is associated with fewer perforations than the progesteronereleasing IUD. Risk factors for uterine perforation include an immobile or extremely verted uterus and, most significantly, an inexperienced
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in~erter.4~ Lactation does not increase the risk of perf~ration.~ Most perforations occur when the uterus is initially sounded. The sound is the first instrument introduced into the uterus. The uterine sound is narrower and less flexible than the IUD introducer. Using contemporary insertion techniques in which the IUD is placed at the fundus and the introducer is withdrawn, the risk of IUD perforation should approach zero. Sudden loss of pressure, a uterine depth greater than anticipated by bimanual examination, and unexplained patient pain are suggestive of uterine perforation. The device should be removed expeditiously if possible and the patient carefully evaluated for a few hours. Fortunately, most perforations occur in the midline through the posterior wall of the uterus and do not cause serious complications. If the device cannot be removed, if the patient continues to experience pain or demonstrates evidence of blood loss, or if there is possible bowel damage, emergency surgery may be indicated. Laparoscopy is usually sufficient, but exploratory laparotomy may be necessary if the bowel or a vascular structure has been injured.
Postinsertion Instructions
The IUD requires little maintenance. The patient should be instructed to check the length of the string after menses each month to ensure that the device is still in place. Although the risks of postinsertion problems are small, the woman should be advised to watch for symptoms consistent with the three main IUD-related problems (pregnancy, expulsion, and infection) and to return for further professional evaluation should any develop. A moderate increase in menstrual blood loss and cramping can occur in the first 2 to 3 months following insertion of the copper IUD. Experts recommend that women use NSAIDs prophylactically for the first 3 days of each of the first two to three cycles to prevent this problem.
Routine Follow-Up
Partial expulsions outnumber complete expulsions by more than a factor of three, and most partial expulsions are silent and delayed beyond the first month of use.44As a result, some clinicians have recommended that the first routine visit be scheduled 3 months after insertion. The scheduled first follow-up, 1-month visit was developed for Lippes Loop users who needed to have the tail strings shortened after the IUD ”settled in” the uterus. Now that IUD position is determined at insertion, the date of the first visit should be chosen to address issues relevant to contemporary IUDs.
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LONGER-TERM MANAGEMENT ISSUES Vaginal Bleeding and Infection Risks
The copper IUD typically increases menstrual blood loss by about 30%. Prophylactic NSAIDs may reduce this problem. The progesteronereleasing IUD is more likely to induce amenorrhea or irregular spotting, which require no therapeutic intervention in the absence of pregnancy. Acute onset of heavy bleeding and cramping may herald incipient IUD expulsion. The diagnosis is confirmed on examination if the strings appear to have greatly lengthened, if the device is felt within the cervical canal with a uterine sound, or if the IUD is visualized in the canal with the aid of an endocervical speculum. The IUD should be promptly removed; a replacement unit can be placed immediately if the woman is an IUD candidate and wants it. Women in whom candida vaginitis or bacterial vaginosis develops during IUD use can be treated routinely. There is a theoretical concern that the IUD tail string may provide a safe haven for Cundidu ulbicuns and increase the incidence of resistant infections, but prolonged therapy is effective if the problem arises. New-onset trichomonal infection may indicate that the patient is at risk for more serious STDs and that she may no longer be a candidate for an IUD. Routine treatment with oral metronidazole is usually effective, but the patient needs reevaluation of her future STD risk status. Women in whom gonococcal or chlamydia1 cervicitis or mild PID develops should be given appropriate outpatient antibiotics. Once serum levels have been achieved, the IUD should be removed with the patient’s consent. The slight delay in IUD removal is designed to reduce the risk of bacteremia. If there is a concern for actinomycosis in an IUD user who presents with salpingitis, the routine intravenous antibiotic treatments recommended by the CDC for PID should be supplemented with highdose penicillin until tests confirm the absence of actinomyces. In addition, when the IUD is removed, it should be scraped and these scrapings sent for cytology to rule out actinomycosis. Cultures are more accurate than cytology, but the specimen must be rapidly plated for the culture to be informative. Many sites are unable to transport the IUD to their laboratories rapidly enough for testing. The incidence of cervical colonization with actinomyces increases with the duration of IUD use. Upper tract involvement is extremely rare but serious. If a Papanicolaou smear demonstrates sulfur granules (Gupta bodies), the cytologist will report ”actinomyces-like organisms.” Women with these reports should be contacted, asked about symptoms (intermenstrual bleeding or spotting, pelvic pain, or deep thrust dyspareunia), and examined for signs of actinomycotic PID. Several treatment options are available for the asymptomatic woman with an incidental cytologic finding of actinomyces-like organisms. The first and most frequently recommended intervention is to counsel the patient about her Papanicolaou smear results, advise her that she is at slightly higher risk
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of PID, and instruct her to repeat pelvic examination in 6 months or earlier if she should experience any symptoms. Alternatively, the patient may be treated with 10 to 14 days of penicillin, erythromycin, or tetracycline and undergo a repeat Papanicolaou smear to document clearance. To reduce unnecessary antibiotic treatment, cultures for actinomyces may be obtained to identify the minority of women with this colonization, offering antibiotics therapy only to women with culture-proven infections. Rarely, it may be appropriate to remove the IUD, scrape or culture it, and provide follow-up care as indicated by the outcome of these tests. Women may have another IUD inserted after repeat Papanicolaou smears indicate clearance. Users of IUDs are not at increased risk for any other significant Papanicolaou smear abnormalities. On the contrary, IUD users should be at lower risk for cervical dysplasia than the general population because they are at lower risk for STDs. Because the tail strings may irritate the cervical canal, many IUD users have benign reparative changes reported on a Papanicolaou smear. Pregnancy with Use of the Intrauterine Device
If a patient presents early in pregnancy with an IUD, an ectopic implantation must be ruled out. Although the IUD significantly reduces a woman's baseline risk for tuba1 pregnancy, it does not protect against ectopic pregnancy as well as it protects against intrauterine pregnancy. Overall, 5% to 8% of pregnancies that occur with copper IUD use are ectopic. If the pregnancy is intrauterine and is desired, further management will depend on the status of the IUD tail strings. If the strings are visible early in pregnancy, the standard recommendation is to remove the IUD. This recommendation is based on experience from the 1970s showing that if the IUD was left in place during the first trimester, the risk of pregnancy loss was twice as great (40% to 54%) than when it was removed (20%).42Maternal health risks (predominantly sepsis) were also greatly increased if the IUDs were retained. Despite these findings, the CDC reports that there have been no cases of maternal death in the United States owing to IUD-related septic abortion since 1977.2 In the early second trimester, if the decision is made to remove the device, the procedure should be performed in a setting that can handle potential hemorrhage. It is unusual for IUD strings to be visible late in pregnancy; their presence raises the index of suspicion for placenta previa. If the tail strings are not visible in pregnancy, a prompt ultrasound can rule out an undetected expulsion or verify that the IUD is intrauterine. Despite published descriptions of hysteroscopically guided IUD removals in pregnancy, that procedure is still e~perimental.'~ The patient should be reassured that the IUD does not increase the risk of fetal rnalformation~,~~ but she should also understand that the device does increase her risk of preterm labor. The patient should be instructed to
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seek prompt medical care if any symptoms associated with intrauterine infection develop because the risk of delivery before 37 weeks gestation is two to four times higher in women with IUDs. The absolute risk of prematurity with IUDs left in situ (regardless of string status) has been reported to range from 18.7%6to 37.5%.42 Missing Tail Strings
The IUD tail strings may not be apparent because they were excessively trimmed, because they have become twisted in the endocervical canal, or because the device has been expelled or perforated in the peritoneal cavity. Nonpregnant women with missing IUD tail strings can easily be evaluated. The first step is to twist a cytobrush inside the cervix to determine whether the strings have inadvertently become tangled within the cervical canal. A uterine sound can be used to probe the uterine canal to detect the base of a partially expelled IUD. Occasionally, an endocervical speculum can be helpful in visualizing the IUD tip or the strings. If these maneuvers are not successful, two options are available. Tread retractors can be passed anteriorly, posteriorly, and laterally to snag the tail strings, or alligator forceps can be used to search within the endometrial cavity and to remove the IUD. A tenaculum must always be placed to stabilize the uterus before any endometrial manipulation. Alternatively, ultrasound studies, especially transvaginal ultrasound, can be performed to locate the IUD. If the IUD is not seen on ultrasound, it has most likely been expelled. Because very unusual sites of migration for perforated IUDs have been described,37 some experts suggest an abdominal radiograph in this situation. If the device has perforated in the peritoneal cavity, surgical removal is necessary because the IUD induces a sterile abscess and can cause bowel damage if left in situ. If the IUD is found to be in the endometrial cavity, it can be removed with alligator forceps (with or without ultrasound guidance). Some clinicians have suggested that IUDs with intrauterine strings can be followed up with serial ultrasound studies as one might manage a tailless IUD. If that choice is made, the ultrasound evaluation needs to be done after the menses because the T-shaped devices move vertically with endometrial growth.15 CONDITIONS FOR REMOVAL
In general, an IUD should be removed when it expires, when a woman no longer qualifies as an IUD candidate (e.g., STD risk, 1 year after menopause, pregnancy desired), when the woman sustains a side effect that cannot be otherwise treated, or when the woman requests removal. All removals must be performed with patient consent. To remove an IUD, the clinician grasps the strings close to the cervical 0s with a sponge forceps or vaginal packing forceps and pulls toward the
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introitus to deliver the device. If significant resistance is felt when traction is placed on the strings, the device may be embedded in the endometrium. A gentle rocking or twisting motion usually frees the device and permits its removal. If reasonable traction does not produce the device or if the strings break, alligator forceps can be introduced into the endometrial cavity to apply pressure directly on the IUD. If there is any suspicion that the device may have perforated the uterine wall, the procedure should be delayed until ultrasound can more completely define the situation. Hysteroscopically directed removal is helpful for removing a deeply embedded device. RETURN TO FERTILITY
The contraceptive effects of the IUD are rapidly reversible; therefore, the IUD is very appropriate as an interval method to help couples space their pregnancies. Pregnancy rates following removal of the copper IUD have been reported in several studies. The median time to planned pregnancy is about 3 month^.^ Younger women had more rapid and more complete (100%) return to fertility. After controlling for age at time of removal, the duration of use had no impact on the time to return to fertility. Wilson47showed that the fertility rates for women who had their IUDs removed for complications were not significantly different from the rates for women who had their IUDs removed to conceive. Wilson's data also reconfirm that the ectopic pregnancy rates after IUD removal are not higher in either group than in the general population." Table 3 summarizes clinical observations of pregnancy following IUD removal. COST-EFFECTIVENESS
Several analyses have verified that the copper IUD is the most costeffective method of birth control currently available in the United States. Analysts have calculated the net benefits of IUD use over a 5-year period Table 3. PREGNANCY FOLLOWING REMOVAL OF AN INTRAUTERINE DEVICE (IUD) Percent Pregnant by Month After Removal Type of IUD
1
3
6
12
Copper IUD* Progesterone-releasing IUDt Levonorgestrel IUD$
27 24 -
69 49
84 67 79-96
89 76 -
-
*Diaz S, Pavez M, Cardenas H, et al: Recovery of fertility and outcome of planned pregnancies after removal of Norplant subdermal implants or copper-IUDs. Contraception 35567, 1987. tErickson R, Mitchell C, Pharriss B, et al: The intrauterine progesterone contraceptive system. Advances in Planned Parenthood 11:167, 1976. $Anderson K, Batar I, Rybo G: Return to fertility after removal of a levonorgestrel-releasing intrauterine device and NovaT. Contraception k 5 7 5 , 1992.
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by summing all of the pregnancy-related health care costs and deducting all of the costs associated with the IUD, its insertion, and its failures. In the typical health maintenance organization environment, each copper IUD inserted was shown to save the health care system $14,122 in 5 years.41 NEWER DEVICES
It is expected that the levonorgestrel IUD will become available in the United States within a year. Carrying the brand name Minera (Berlex Laboratories, Wayne, NJ), it will probably be approved for 5 years of use. The device is a T-shaped polyethylene frame with a cylinder of polydimethylsiloxane/ levonorgestrel molded within its stem that releases 20 k g of levonorgestrel per day. Worldwide trials have shown that the first-year typical use failure rate is 0.1%. The mechanisms of action are related to the local application of progestin and are similar to the mechanisms of the progesterone-releasing IUD. The cervical mucus thickens and prevents the passage of sperm into the upper genital tract. The inflammatory changes induced by the plastic frame also contribute to efficacy by acting as a spermicide. The progestin suppresses the endometrium and occasionally suppresses ovulation. The side effects with this device are also influenced by the progestin. Menstrual changes are noted by most users. Women generally experience heavier bleeding in the first cycle but are more likely to experience oligomenorrhea, spotting, or amenorrhea in subsequent cycles. Although the progestin will not reliably suppress ovulation, it can slow the atresia of existing follicles; therefore, an increased risk of functional ovarian cysts is associated with the levonorgestrel IUD. The circulatory levels of progestin are lower than with other progestin contraceptives, thus a few women may complain of bloating or breast tenderness with the levonorgestrelreleasing IUD. This IUD has many attractive features. It does not increase a woman’s risk for PID. It has been shown to be an effective treatment for menorrhagia.20Blood loss is reduced by 86% at 3 months and by 97% after 12 months of use. The levonorgestrel IUD also can be used to protect the uterus from estrogen stimulation in postmenopausal women, especially in women who do not tolerate systemic progestin. A frameless IUD (FlexiGard or Cu-Fix) is used in Scandinavia for nulliparous women with smaller endometrial cavities. It consists of six pledgets of copper with a surface area of 330 mm2 placed in tandem on a polypropylene string that is knotted at both ends. The knot at the top of the string is embedded into the myometrium at insertion, and the strings below the lower knot protrude through the cervix for ongoing monitoring. SUMMARY
The intrinsic appeal of the convenience and effectiveness of the IUD has increased interest in these devices in the United States in recent
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years." Understanding the uniqueness of the Dalkon Shield experience and applying the lessons learned about appropriate candidate selection should continue to reduce any lingering liability concerns. One lawsuit has been filed against the copper IUD in the 12 years that it has been available in the United States. If legislation requiring insurance coverage for IUDs and other prescription contraceptive agents continues to be passed by more states, the use of IUDs will continue to grow. The introduction of new IUDs with different side-effect profiles will expand the number of US women who can and will be interested in using this method of birth control. References 1. Alvarez F, Brache V, Fernandez E, et al: New insights on the mode of action of intrauterine contraceptive devices in women. Fertil Steril 49:768, 1988 2. Atrash HK, Frye A, Hogue CJR Incidence of morbidity and mortality with IUD in situ in the 1980s and 1990s. In Bardin CW, Mishell DR Jr (eds): Proceedings from the Fourth International Conference on IUDs. Boston, Butternorth-Heinemann, 1994, p 76 3. Belhadj H, Sivin I, Diaz S, et al: Recovery of fertility after use of the levomorgesrel20 mcg/d or copper T 380Ag intrauterine device. Contraception 34261, 1986 4. Burkman RT, and the Women's Health Study: Association between intrauterine device and pelvic inflammatory disease. Obstet Gynecol57269, 1981 5. Centers for Disease Control and Prevention (CDC): Current trends: IUD safety. Report of a nationwide physician survey-editorial note-1997. IUD safety. MMWR Morb Mortal Wkly Rep 46:971, 1996 6. Chaim W, Mazor M Pregnancy with an intrauterine device in situ and preterm delivery. Arch Gynecol Obstet 252:21, 1992 7. Chi I: What have we learned from recent IUD studies: A researcher's perspective. Contraception 48:81, 1993 8. Cramer DW, Schiff I, Schoenbaum SC, et al: Tuba1 infertility and the intrauterine device. N Engl J Med 312941, 1985 9. Dajani AS, Taubert KA, Wilson W: Prevention of bacterial endocarditis: Recommendations by the American Heart Association. JAMA 2771794, 1997 10. Daling JR, Weiss NS, Metch BJ, et al: Primary tuba1 infertility in relation to the use of an intrauterine device. N Engl J Med 312:937, 1985 11. Dardano KL, Burkman RT The intrauterine contraceptive device: An often-forgotten and maligned method of contraception. Am J Obstet Gynecol lSl:l, 1999 12. Ebi KL, Pizali RO, Rosenberg M, et al: Evidence against tailstrings increasing the rate of pelvic inflammatory disease among IUD users. Contraception 53:25, 1996 13. El-Habashi M, El-Sahwi S, Gawish S, et al: Effect of Lippes loop on sperm recovery from human fallopian tubes. Contraception 22549, 1980 14. Farley TMM, Rosenberg MJ, Rowe PJ, et al: Intrauterine devices and pelvic inflammatory disease: An international perspective. Lancet 339:785, 1992 15. Fadndes D, Bahamondes L, F a h d e s A, et al: T-shaped IUDs move vertically with endometrial growth and involution during the menstrual cycle. Contraception 57:413, 1998 16. Grafenberg E: An intrauterine contraceptive method. In Sanger M, Stone HM, (eds): The Practice of Contraception: Proceedings of the 7th International Birth Control Conference, Zurich, Switzerland. Baltimore, Williams & Wilkins, 1930, p 33 17. Grimes DA, Schulz KF: Prophylactic antibiotics for intrauterine device insertion: A metaanalysis of the randomized controlled trials. Contraception 6057, 1999 18. Huber SC, Piotrow PT, Orlans FB, et al: IUDs reassessed: A decade of experience. Popul Rep B 3(2):2148, 1975 19. Hucke J, Campo RL, Kozlowski P, et al: Experience with hysteroscopy or ultrasound-
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controlled removal of an intrauterine spiral with no visible thread in early pregnancy. Geburtshilfe und Frauenheilkinde 51:31, 1991 20. Irvine GA, Campbell-Brown MB, Lumsden MA, et al: Randomised comparative trial of the loevnorgestrel intrauterine system and norethisterone for treatment of idiopathic menorrhagia. Br J Obstet Gynaecol 105:592, 1998 21. Ishihama A Clinical studies on intrauterine rings, especially the present state of contraception in Japan and the experiences in the use of intrauterine rings. Yokohama Medica Bulletin 10:89, 1959 22. Kjos SL, Ballagh SA, La Cour M, et al: The copper T380A intrauterine device in women with type I1 diabetes mellitus. Obstet Gynecol 841006, 1994 23. Lee NC, Rubin GL, Borucki R The intrauterine device and pelvic inflammatory disease revisited: New results from the Women’s Health Study. Obstet Gynecol 721, 1988 24. Mishell DR Jr, Bell JH, Good RG, et al: The intrauterine device: A bacteriologic study of the endometrial cavity. Am J Obstet Gynecol 96:119, 1996 25. Moyer DL, Rimdusit S, Mishell DR Jr: Sperm distribution and degradation in the human female reproductive tract. Obstet Gynecol 352331, 1970 26. Nelson AL: Intrauterine device practice guidelines: Medical conditions. Contraception 58:59S, 1998 27. Oppenheimer W Prevention of pregnancy by the Grafenberg ring method: A reevaluation after 28 years’ experience. Am J Obstet Gynecol78446, 1959 28. Ota T A study on birth control with an intrauterine instrument. Japanese Journal of Obstetrics and Gynecology 17210, 1934 29. Potts DM, Champion CB, Kozuh-Novak M, et al: IUDs and PID: A comparative trial of strings versus stringless devices. Adv Contracept 7231, 1991 30. Pust K Ien vrauchbarer frauenschurtz. Deutsche Med Wochenschrift 49:952, 1923 31. Richter R Ein mittel zur verhurung der kinzeption. Dtsch Med Wochensch 35:1525, 1909 32. Riviera R, Yacobson I, Grimes D: The mechanism of action of hormonal contraceptives and intrauterine contraceptive devices. Am J Obstet Gynecol 118:1263, 1999 33. Sagiroglu N: Phagocytosis of spermatozoa in the uterine cavity of women using intrauterine device. Int J Fertil 16:1, 1971 34. Segal SJ, Alvarez-Sanchez F, Adejuwon CA, et al: Absence of chorionic gonadotropin in sera of women who use intrauterine devices. Fertil Steril44214, 1985 35. Skjeldestad FE, Halvorsen LE, Kahn H, et al: IUD users in Norway are at low risk for genital C. trachomatis infection. Contraception 54209, 1996 36. Speroff L, Damey PD: A Clinical Guide for Contraception, ed 2. Baltimore, Williams & Wilkins, 1996, p 191 37. Stutz JA, Wilkinson SA: Psoas abscess: An unusual complication of an intrauterine contraceptive device. Br J Obstet Gynaecol 106:177, 1999 38. Tatum HJ, Beltran RS, Ramos R, et al: Immediate postplacental insertion of GYNE-T 380 and GYNE-T 380 postpartum intrauterine contraceptive devices: Randomized study. Am J Obstet Gynecol 175:1231, 1996 39. Tatum HJ, Schmidt FH, Phillips D, et al: The Dalkon Shield controversy: Structural and bacteriological studies of IUD tails. JAMA 231:711, 1975 40. Treiman K, Liskin L, Kols A, et al: IUDs-an update. Popul Rep B 23(6):1-35, 1995 41. Trussell J, Leveque JA, Koenig JD, et al: The economic value of contraception: A comparison of 15 methods. Am J Public Health 85:494, 1995 42. UK Family Planning Research Network Pregnancy outcome associated with the use of IUDs. Br J Fam Plann 15:7, 1989 43. United Nations Development Programme/United Nations Population Fund/ World Health Organization/ World Bank, Special Programme of Research, Development and Research Training in Human Reproduction: Long-term reversible contraception: Twelve years of experience with the TCu380A and TCu220C. Contraception 56341, 1997 44. Walsh T, Grimes D, Frezieres R, et al: Randomised controlled trial of prophylactic antibiotics before insertion of intrauterine devices. Lancet 351:1005, 1998 45. White MK, Ory HW, Rooks JB, et al: Intrauterine device termination rates and the menstrual cycle day of insertion. Obstet Gynecol 55220, 1980
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46. Wilcox AJ, Weinberg CR, Armstrong EG, et al: Urinary human chorionic gonadotropin among intrauterine device users: Detection with a highly specific and sensitive assay. Fertil Steril 47265, 1987 47. Wilson JC: A prospective New Zealand study of fertility after removal of copper intrauterine devices for contraception and because of complications: A four-year study. Am J Obstet Gynecol 160391, 1989 48. World Health Organization: Improving Access to Quality Care in Family Planning: Medical Eligibility Criteria for Contraceptive Use, vol. 76. Geneva, World Health Organization, 1996, p 27 49. World Health Organization: Mechanism of Action, Safety and Efficacy of Intrauterine Devices. Report of a WHO Scientific Group. Technical Report Series 753. Geneva, World Health Organization, 1987, p 1 50. Zipper JA, Tatum HJ, Medel M, et al: Contraception through the use of intrauterine metals. I. Copper as an adjunct to the "T" device: The endouterine copper "T." Am J Obstet Gynecoll 109:771, 1971
Address reprint requests to Anita L. Nelson, MD Harbor-UCLA Medical Center 1000 W Carson Street, Box 474 Torrance, CA 90509-2910 e-mail: AnitaNelsonWHCQearthlink.net
~~
UPDATE IN CONTRACEPTION
~
0889-8545/00 $15.00
+ .OO
THE INTRAUTERINE CONTRACEPTIVE DEVICE Anita L. Nelson, MD
Before its introduction into the United States in 1988, the copper intrauterine device (IUD) was carefully tested following the Food and Drug Administration (FDA) regulations for new drugs. The Centers for Disease Control and Prevention (CDC) closely monitored postintroduction events for currently available IUDs for nearly a decade before concluding that IUDs were safe and effective methods of birth contr01.~ Because IUDs dramatically reduce the risk of unintended pregnancy and are convenient, rapidly reversible, and cost-effective, it is remarkable that this method is so infrequently used in the United States. Less than 1% of married contracepting women in the United States use IUDs. Worldwide, the IUD is the most frequently used method of reversible contraception; 106 million women (10% of married women of reproductive age) were using IUDs for birth control in 1995.4OIn Western Europe, rates range from 7% to 19%. Many US physicians are reluctant to recommend the IUD to their patients because of the negative clinical experience and medicolegal nightmares that resulted from flaws in the Dalkon Shield and earlier misapplications of the IUD. Nevertheless, the dissemination of new scientific evidence and recent clinical experience support greater use of IUDs in the United States.
From the Department of Obstetrics and Gynecology, University of California Los Angeles School of Medicine, Los Angeles; and Women’s Health Care Programs, HarborUniversity of California Los Angeles Medical Center, Torrance, California
OBSTETRICS AND GYNECOLOGY CLINICS OF NORTH AMERICA VOLUME 27 * NUMBER 4 * DECEMBER 2000
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HISTORICAL OVERVIEW Early International Intrauterine Devices
The first IUDs for women were developed in nineteenth-century Germany as variations of vaginal pessaries. These early IUDs were rigid metal appliances that extended from the vagina or the ectocervix through the cervical canal into the endometrium.1sThey were multipurpose devices that only indirectly acted as contraceptive^.^^ In 1902 Hollweg introduced a self-inserted pessary that extended into the uterus and that was intended explicitly for contraception. In 1909 Richter31 introduced a silkworm-catgut ring with a nickel and bronze wire protruding through the cervical 0s. Although there is no written record of how the male partner responded to this metal protrusion at the top of the vaginal vault, PusPo rapidly replaced the metal wire with catgut thread and added features of the old button-type pessary. Given that these devices were used by women in the days before antibiotics or nonsteroidal antiinflammatory drugs (NSAIDs), their use quickly became associated with serious infections and significant patient discomfort. These side effects created such an enduring negative image for IUDs that when Grafenberg introduced the first true IUD in the 1920s, it was generally rejected by the medical community. The Grafenberg ring was a tailless device composed of “German silver” an alloy of copper, nickel, and zinc.16 Because of its extreme flexibility, expulsion could easily remain undetected, exposing the user to unwanted pregnancy. The Ota ring was introduced in Japan in 1934 to correct that problem; it added a small central disk with three spokes that radiated out to the inner surface of the gold or gold-plated ring to stabilize the device and reduce expulsion.28Throughout World War I1 and the postwar baby-boom years, IUDs were in general use only in Israel and Japan. In 1959 a landmark issue of the American Journal of Obstetrics and Gynecology, in which Ishihama and Oppenheimer reported their clinical experience with IUDs, inspired worldwide interest in these devices and triggered an outpouring of creative new designs.21,27 Early Intrauterine Devices
Although several investigators continued to create metal wire devices, most of the successful new IUDs were based on polyurethane frames embedded with barium sulfate to make them visible on radiographs. Within a decade, several plastic devices, such as the S-shaped Lippes Loop, the Tatum T, and the Safe-T-Coil, were in widespread use. In 1969, Zipper reported that copper had a profound impact on the When Tatum wrapped a thin copper wire around the stem of his plastic IUD to create the Copper T200, the first-year typical failure rates decreased to 1.5% to 2%. In 1971 the Copper 7 IUD was introduced and found favor with physicians for use in nulliparous
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adolescent women who had difficulty successfully using oral contraceptive pills. In the late 1960s, investigators at John Hopkins developed the Dalkon Shield-an all-plastic device with small plastic protrusions around its edges to help it adhere to the endometrium and reduce the risk of expulsion. Clinical trials conducted following the FDA regulations for devices (not drugs) revealed that the first-year failure rate was 1%-lower than the rate for any IUD available at the time. Early in product development, it was discovered that the original tail strings tended to break during attempted IUD removal. Unfortunately, these strings were replaced by a sheathed polyfilament string. When the strings were cut, the sheath was compromised. Bacterial pathogens could enter the hundreds of small interfilament interstices within the tail string and, by wicking or capillary action, travel through the cervix protected from its mucous defense systems. In about 25% of the units, the protective sheath was also broken at the knot at the base of the unit, which allowed the pathogens an exit pathway into the vulnerable endometrial cavity. This unique design flaw accounted for the significant incidence of pelvic inflammatory disease (PID) and its sequela sustained by Dalkon Shield users. When cultures were taken of the tail strings of the Dalkon Shield aerobic organisms were found on 42% of the strings and anaerobes on 86% of the strings.39All currently used IUDs are fitted with monofilament tails, which are consistently sterile when cultured. Direct comparison studiesz9 and meta-analysis'* have failed to find any increased risk of PID for women using IUDs with monofilament tail strings when compared with women using tailless IUDs. Lessons Learned: Infection Risks
The risk of infection with IUD use is related to the woman's underlying risk for acquiring sexually transmitted diseases (STDs). Lee and co-workersu found that among users of IUDs other than the Dalkon Shield, the risk for PID varied by relationship status. Women in ongoing relationships (cohabitating or currently married) had no statistically significant increased risk for PID when using IUDs, whereas previously married and never-married IUD users showed relative risks for PID of 1.8 and 2.6, respecti~ely.~~ Burkman4reported that the greatest risk factor for PID with IUD use was multiple sex partners. When women with one partner who had never used an IUD were used as the referent population, women who had one partner and who used a copper IUD showed no increased risk for primary tubal infertility. In contrast, women with multiple sexual partners who used IUDs showed an increased risk for tubal infertility.8,lo After correcting the design flaws of the IUD tail string and correctly identifying appropriate IUD candidates, the remaining issue for PID infection was the transient contamination of the endometrial cavity at the time of insertion. Farley and co-~orkers'~ reconfirmed Mishell's
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observationz4that PID infections with IUD use are concentrated in the 20 days following insertion. In Farley’s international study, the absolute risk for PID in that early period was about 1%.Recent studies conducted in developed countries (where patient selection and testing practices are comparable with procedures in the United States) have found that the incidence of PID is only about 1 case per 1000 insertions.35,44 TYPES OF INTRAUTERINE DEVICES AVAILABLE IN THE UNITED STATES
The copper IUD (ParaGardT 380A, Ortho-McNeil Pharmaceuticals, Raritan, NJ) is a T-shaped polyethylene device with 380 mm2of exposed surface area of copper on its arms and stem. The polyethylene frame also contains barium sulfate, which renders it radiopaque. The white polyethylene monofilament tail strings pass through and are knotted below a 3-mm plastic ball at the base of the stem. The ball helps reduce cervical perforation with expulsion. The copper IUD is approved by the FDA for up to 10 years of use, but a recent study suggests that it may be effective for at least 12 years. No pregnancies were reported before the eighth year of ~ s e . 4 ~ The progesterone-releasing IUD (Progestasert, Alza Laboratories, Palo Alto, CA; acquired by Abbott Laboratories, North Chicago, IL in 1999) is a T-shaped device made of ethylene/vinyl acetate copolymer. The frame is radiopaque. The stem contains a reservoir of 38 mg of progesterone that is released at a rate of 65 pg/day. The two arms are used only to stabilize the device. The device has two blue-black monofilament strings attached at a hole in the base of the stem. The progesterone-releasing IUD is approved for 12 months of use in the United States. Other IUDs are currently used by women living in the United States. Before 1985, tens of thousands of plastic IUDs with an unlimited life span (e.g., the Lippes Loop and Safe-T-Coils)were inserted. Some of these women plan to continue to use these IUDs until they reach menopause. In addition, many women who immigrate to this country use IUDs that have not been approved in the United States. In Europe, a levonorgestrel-releasing IUD and a frameless copper IUD have been in widespread use for several years. In the Middle East and Central and South American, women still have access to the inert plastic IUDs. In Canada, women have different copper and silver IUDs. The vast majority of immigrant IUD users come from Asia, where tailless circular IUDs are most common. EFFICACY
Because IUDs require little patient action for their continued action, the typical failure rates for IUDs closely approximate the failure rates
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associated with correct and consistent use; however, the effectiveness of the IUD varies by model. The copper IUD has a first-year failure rate of 0.7% with typical use. Nulliparous women have slightly higher failure rates (0.8%) than parous women. The copper IUD has a cumulative 10year typical failure rate of 2.1% to 2.7%, which is less than the typical first-year failure rate for oral contraceptives. The progesterone-releasing IUD has a first-year typical use failure rate of 2%. The Lippes Loop and Safe-T-Coil IUDs have a first-year failure rate of 3%, but current users of these IUDs may experience significantly lower pregnancy rates because they have successfully used their devices for so many years. Table 1 summarizes the first-year failure rates. SELECTION OF CANDIDATES
Product labeling indicates that the IUD user should be a parous woman with no history of PID who is in a stable mutually monogamous relationship. The parous woman need not have completed her childbearing but must have demonstrated her fertility. It is estimated that more than 10 million American women fit all aspects of this patient profile and have no contraindications to IUD use; however, many more millions of women may also be excellent candidates for IUD use. Nulliparity has never been a contraindication to IUD use. Although is recognized that IUD insertion through a cervix that has not been previously dilated may be slightly more challenging, many parous women who have been electively delivered by cesarean section present the same challenges. The uterine cavity of a nulliparous woman is smaller. As a result, the expulsion and failure rates are slightly higher in women who have never borne children, but the IUD still provides excellent pregnancy protection for these women. The real concern with IUD use in nulliparous women who are not at risk for STDs is not strictly medical but medicolegal. Ten percent to 15%of American couples sustain infertility problems. Placing IUDs in women with unproved fertility exposes the IUD, and potentially the provider, to the risk of charges after IUD removal that the IUD caused infertility. Careful preinsertion counseling is needed to explain potential unrecognized infertility to nulliparous patients. Table 1. FIRST-YEAR FAILURE RATES FOR THE INTRAUTERINE DEVICE (IUD) Correct and Consistent Use (%)
Typical Use
Type of IUD Progesterone IUD Copper IUD Levonorgestrel IUD*
1.5 0.6 0.1
2.0 0.8
(W 0.1
*Not FDA-approved by July 2000. Datafrom Stewart GK: Intrauterine devices (IUDs). In Hatcher RA, Trussell J, Stewart F, et a1 (eds): Contraceptive Technology, 17 ed. New York, Ardent Media, 1998, p 514.
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The recommendation that the woman considered for an IUD should never have been diagnosed with PID is too restrictive. The concerns regarding IUD use in a woman with a history of PID are that it may be a marker for an ongoing risk for STD exposure, and that the salpingitis may have reduced the patient's fertility. Clearly, a 37-year-old woman sustaining PID at age 16 years but who has been in a mutually monogamous relationship for the last 15 years with the father of her six children would be a reasonable IUD candidate. The World Health Organization (WHO) standards require that a woman with a history of PID have at least one pregnancy following her latest episode of PID before she is considered for IUD use.48 Beyond the fundamental condition that a woman be in a stable mutually monogamous relationship (putting her at low risk for STDs), there are other generic contraindications to IUD use (Table 2). Pregnancy, unexplained abnormal uterine bleeding, acute cervical or vaginal infections, evidence of cervical carcinoma, and severe immunocompromise (chemotherapy, radiotherapy, acquired immunodeficiency syndrome) are contraindications to the use of any IUD as long as the condition exists.
SELECTION OF AN INTRAUTERINE DEVICE The contraindications and side effects of each of the IUDs direct women to select one IUD over another. Currently, the first-line choice for most women seeking intermediate to long-term contraception is the Table 2. CONTRAINDICATIONS TO INTRAUTERINE DEVICES (IUDS)
General Pregnancy Acute unresolved cervicitis (current or within the last 3 months) Pelvic inflammatory disease, endometritis, or pelvic tuberculosis (current or within the last 3 months) Distorted uterine cavity Uterine or cervical carcinoma Unexplained vaginal bleeding Severe immunocompromise (e.g., acquired immunodeficiency syndrome, chemotherapy) Multiple sexual partners or partner with multiple sexual partners IUD specific Copper IUD Uterine cavity <6 or >9 cm Copper allergy Wilson's disease Severe anemia Menorrhagia Severe dysmenorrhea Progesterone-releasing IUD Uterine cavity (6 or >10 cm History of ectopic pregnancy Diabetes
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copper IUD because of its superior efficacy and prolonged duration of effect. Women with anemia, heavy menses, dysmenorrhea, or bleeding dyscrasias may benefit from using a progesterone-releasing IUD, which does not increase menstrual blood loss or cramping. The maximum uterine depth differs by device. The copper IUD can be placed in a uterus that sounds to a depth of up to 9 cm, whereas the progesteronereleasing IUD can be used in a uterus with a depth up to 10 cm. Many women with medical conditions may benefit from features of particular IUDs.26 The copper IUD has been show to reduce the risk of ectopic pregnancy significantly when compared with the risk in women using no method; therefore, women who have a history of ectopic pregnancy may be candidates for the copper IUD. The progesterone-releasing IUD has not demonstrated such protection, thus it is not appropriate for women with previous tuba1 pregnancies. Diabetic women are candidates for the copper IUD but not for the progesterone-releasing IUD.22Copper allergy and Wilson's disease (a copper storage disease) are contraindications to the use of copper-bearing IUDs. Table 2 summarizes the contraindications to IUD use. MECHANISMS OF ACTION Copper Intrauterine Devices
Misguided concerns that the IUD works as an abortifacient have seriously limited IUD use by many women and have prevented many providers from offering IUDs. The evidence is clear that the IUD does not work as a postimplantation abortifa~ient.~~ Segal and co-workersM monitored 30 women using IUDs by measuring serial beta-human chorionic gonadotropin levels for 30 months and did not observe any changes in levels.34In particular, there was no evidence of an initial rise followed by an abrupt drop in levels characteristic of pregnancy interruption. Wilcox and c o - ~ o r k e r sfound ~ ~ one episode of a transient increase in 107 IUD cycles. Moreover, the failure of uterine washings to retrieve eggs in 56 IUD users in contrast to washings yielding eggs in 4 of 115 controls undermines the hypothesis that IUDs work by creating inflammatory endometrial changes that prevent implantation.' The copper IUD is a functional spermicide; the copper ions released from the device interfere with sperm mobility and create a foreign-body reaction that results in a spermicidal endometrium. Sperm counts in the cervical mucus are significantly lower in IUD users than they are in nonusers. Oviduct counts of sperm are vanishingly small in IUD users. El-HabashiI3 and M ~ y e rand ~ ~their co-workers reported finding no sperm in the fallopian tubes of 30 women with IUDs. Microscopic studies demonstrate that the inflammatory changes in the endometrium are spermicidal. Clusters of leukocytes are seen engulfing the sperm. S a g i r ~ g l ufound ~ ~ that 2 to 16 hours after coitus, spermatozoa were
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phagocytized in the endometrial cavities of IUD users. The copper ions inhibit sperm penetration into the egg; the acrosomal enzymes needed to dissolve the zona pellucida are not activated in the presence of copper ions. These observations have been verified by clinical in vivo experience. Alvarez and co-workers' performed bilateral total salpingectomies on two groups of women who had coitus at the time of documented ovulation. When the specimens were serially sliced in search of normally dividing ova, indicating fertilization, half of the controls showed normal development of the ova, whereas none of the IUD users showed evidence of ferti1ization.l Progesterone-Releasing Intrauterine Devices The progesterone-releasingIUD is believed to work as an alternative delivery system for progestin. The main mechanism of action is to thicken the cervical mucus and render it impenetrable to sperm. There may be other effects of progesterone on the endometrium, but the levels are insufficient to affect ovulation. The plastic IUD frame also induces a foreign-body inflammation reaction that is spermicidal. INSERTION ISSUES Timing and Preparation for Insertion The IUD can be inserted anytime in a woman's cycle when she is not pregnant. White and c o - ~ o r k e r demonstrated s~~ that expulsion rates for the first three postinsertion cycles were reduced by more than 30% when insertion was delayed until the end of menses. Theoretically, the optimal time for insertion is at the time of ovulation, when the cervical canal is maximally dilated and progesterone can quiet the myometrial contractions triggered by uterine manipulation. Insertion postpartum is best delayed until the uterus is completely involuted (usually, 4-6 weeks after delivery) to reduce the risk of perforation and expulsion. Nevertheless, international work suggests that insertion immediately postpartum (10-20 minutes after delivery of the placenta) is associated with low risks of uterine perforation and expulsion and may be a reasonable alternative for women who have limited access to the medical care system.38Women who have miscarriages or other pregnancy terminations in the first trimester are candidates for immediate IUD insertion unless there is evidence of infection. IUD reinsertion can immediately follow removal of a unit for expiration, expulsion, or partial expulsion. The preparation for IUD insertion is straightforward. Women generally benefit from taking NSAIDs 1 hour before the insertion. A small amount of lidocaine injected at the tenaculum site can reduce the discomfort associated with the placement of that instrument. A small cotton swab generously soaked in 20% Hurricane lidocaine can be placed
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into the cervical canal to reduce insertional discomfort and vasovagal reactions. If the patient has significant cervical stenosis (requiring cervical dilation), a paracervica1 block may be needed. Careful cleansing of the ectocervix, the upper vagina, and the cervical canal is intended to reduce bacterial contamination with insertion. Routine prophylactic antibiotic administration is not warranted in the United States. A recent double-blind prospective study demonstrated no statistically significant difference in PID rates in women who received 500 mg of azithromycin before insertion compared with woman who received a placebo.% It was calculated that the low background rate of postinsertion infection would require enrollment of over 100,000 patients to detect any statistically significant difference. At that rate, the antibiotics would certainly not be cost-effective. A recent meta-analysis of international experience has confirmed that antibiotic prophylaxis confers little benefit.I7 The American Heart Association guidelines for patients at risk for endocarditis suggest that antibiotic prophylaxis before IUD insertion or removal is not necessary? Although patients may need time to digest all of the information included in the patient information brochure and to consider all of the relevant issues, if an informed choice is obtained, insertion can be performed on the same day. In the absence of any clinical evidence of infection and with a reassuringly normal vaginal wet mount, test specimens for cervical infection may be obtained and the IUD promptly inserted. Vaginal microscopy studies are helpful not only in ruling out the presence of leukocytes that accompany cervicitis but also in detecting trichomoniasis and bacterial vaginosis. Patients with gonorrhea or chlamydial cervicitis and perhaps those with trichomoniasis may not qualify for IUD use until they are no longer at risk for STDs. Women with bacterial vaginosis should have that condition treated before insertions because it has been shown to increase the risk of postoperative infections in women undergoing hysterectomy and to more than double the risk of post-abortion endometritis. Insertion Complications
Vasovagal reactions occur in approximately 1% of women with cervical manipulation, particularly in women with significant cervical stenosis. If a patient is known to be at increased risk for vasovagal reactions, appropriate equipment should be available for resuscitation, and a prophylactic paracervical block should be placed. When a transient vasovagal reaction develops during insertion, supportive measures are generally adequate. Severe or prolonged episodes require the removal of the inciting agent (uterine sound or IUD). Uterine perforation occurs once in every 770 to 1600 insertions. The copper IUD is associated with fewer perforations than the progesteronereleasing IUD. Risk factors for uterine perforation include an immobile or extremely verted uterus and, most significantly, an inexperienced
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in~erter.4~ Lactation does not increase the risk of perf~ration.~ Most perforations occur when the uterus is initially sounded. The sound is the first instrument introduced into the uterus. The uterine sound is narrower and less flexible than the IUD introducer. Using contemporary insertion techniques in which the IUD is placed at the fundus and the introducer is withdrawn, the risk of IUD perforation should approach zero. Sudden loss of pressure, a uterine depth greater than anticipated by bimanual examination, and unexplained patient pain are suggestive of uterine perforation. The device should be removed expeditiously if possible and the patient carefully evaluated for a few hours. Fortunately, most perforations occur in the midline through the posterior wall of the uterus and do not cause serious complications. If the device cannot be removed, if the patient continues to experience pain or demonstrates evidence of blood loss, or if there is possible bowel damage, emergency surgery may be indicated. Laparoscopy is usually sufficient, but exploratory laparotomy may be necessary if the bowel or a vascular structure has been injured.
Postinsertion Instructions
The IUD requires little maintenance. The patient should be instructed to check the length of the string after menses each month to ensure that the device is still in place. Although the risks of postinsertion problems are small, the woman should be advised to watch for symptoms consistent with the three main IUD-related problems (pregnancy, expulsion, and infection) and to return for further professional evaluation should any develop. A moderate increase in menstrual blood loss and cramping can occur in the first 2 to 3 months following insertion of the copper IUD. Experts recommend that women use NSAIDs prophylactically for the first 3 days of each of the first two to three cycles to prevent this problem.
Routine Follow-Up
Partial expulsions outnumber complete expulsions by more than a factor of three, and most partial expulsions are silent and delayed beyond the first month of use.44As a result, some clinicians have recommended that the first routine visit be scheduled 3 months after insertion. The scheduled first follow-up, 1-month visit was developed for Lippes Loop users who needed to have the tail strings shortened after the IUD ”settled in” the uterus. Now that IUD position is determined at insertion, the date of the first visit should be chosen to address issues relevant to contemporary IUDs.
THE INTRAUTERINE CONTRACEPTIVE DEVICE
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LONGER-TERM MANAGEMENT ISSUES Vaginal Bleeding and Infection Risks
The copper IUD typically increases menstrual blood loss by about 30%. Prophylactic NSAIDs may reduce this problem. The progesteronereleasing IUD is more likely to induce amenorrhea or irregular spotting, which require no therapeutic intervention in the absence of pregnancy. Acute onset of heavy bleeding and cramping may herald incipient IUD expulsion. The diagnosis is confirmed on examination if the strings appear to have greatly lengthened, if the device is felt within the cervical canal with a uterine sound, or if the IUD is visualized in the canal with the aid of an endocervical speculum. The IUD should be promptly removed; a replacement unit can be placed immediately if the woman is an IUD candidate and wants it. Women in whom candida vaginitis or bacterial vaginosis develops during IUD use can be treated routinely. There is a theoretical concern that the IUD tail string may provide a safe haven for Cundidu ulbicuns and increase the incidence of resistant infections, but prolonged therapy is effective if the problem arises. New-onset trichomonal infection may indicate that the patient is at risk for more serious STDs and that she may no longer be a candidate for an IUD. Routine treatment with oral metronidazole is usually effective, but the patient needs reevaluation of her future STD risk status. Women in whom gonococcal or chlamydia1 cervicitis or mild PID develops should be given appropriate outpatient antibiotics. Once serum levels have been achieved, the IUD should be removed with the patient’s consent. The slight delay in IUD removal is designed to reduce the risk of bacteremia. If there is a concern for actinomycosis in an IUD user who presents with salpingitis, the routine intravenous antibiotic treatments recommended by the CDC for PID should be supplemented with highdose penicillin until tests confirm the absence of actinomyces. In addition, when the IUD is removed, it should be scraped and these scrapings sent for cytology to rule out actinomycosis. Cultures are more accurate than cytology, but the specimen must be rapidly plated for the culture to be informative. Many sites are unable to transport the IUD to their laboratories rapidly enough for testing. The incidence of cervical colonization with actinomyces increases with the duration of IUD use. Upper tract involvement is extremely rare but serious. If a Papanicolaou smear demonstrates sulfur granules (Gupta bodies), the cytologist will report ”actinomyces-like organisms.” Women with these reports should be contacted, asked about symptoms (intermenstrual bleeding or spotting, pelvic pain, or deep thrust dyspareunia), and examined for signs of actinomycotic PID. Several treatment options are available for the asymptomatic woman with an incidental cytologic finding of actinomyces-like organisms. The first and most frequently recommended intervention is to counsel the patient about her Papanicolaou smear results, advise her that she is at slightly higher risk
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of PID, and instruct her to repeat pelvic examination in 6 months or earlier if she should experience any symptoms. Alternatively, the patient may be treated with 10 to 14 days of penicillin, erythromycin, or tetracycline and undergo a repeat Papanicolaou smear to document clearance. To reduce unnecessary antibiotic treatment, cultures for actinomyces may be obtained to identify the minority of women with this colonization, offering antibiotics therapy only to women with culture-proven infections. Rarely, it may be appropriate to remove the IUD, scrape or culture it, and provide follow-up care as indicated by the outcome of these tests. Women may have another IUD inserted after repeat Papanicolaou smears indicate clearance. Users of IUDs are not at increased risk for any other significant Papanicolaou smear abnormalities. On the contrary, IUD users should be at lower risk for cervical dysplasia than the general population because they are at lower risk for STDs. Because the tail strings may irritate the cervical canal, many IUD users have benign reparative changes reported on a Papanicolaou smear. Pregnancy with Use of the Intrauterine Device
If a patient presents early in pregnancy with an IUD, an ectopic implantation must be ruled out. Although the IUD significantly reduces a woman's baseline risk for tuba1 pregnancy, it does not protect against ectopic pregnancy as well as it protects against intrauterine pregnancy. Overall, 5% to 8% of pregnancies that occur with copper IUD use are ectopic. If the pregnancy is intrauterine and is desired, further management will depend on the status of the IUD tail strings. If the strings are visible early in pregnancy, the standard recommendation is to remove the IUD. This recommendation is based on experience from the 1970s showing that if the IUD was left in place during the first trimester, the risk of pregnancy loss was twice as great (40% to 54%) than when it was removed (20%).42Maternal health risks (predominantly sepsis) were also greatly increased if the IUDs were retained. Despite these findings, the CDC reports that there have been no cases of maternal death in the United States owing to IUD-related septic abortion since 1977.2 In the early second trimester, if the decision is made to remove the device, the procedure should be performed in a setting that can handle potential hemorrhage. It is unusual for IUD strings to be visible late in pregnancy; their presence raises the index of suspicion for placenta previa. If the tail strings are not visible in pregnancy, a prompt ultrasound can rule out an undetected expulsion or verify that the IUD is intrauterine. Despite published descriptions of hysteroscopically guided IUD removals in pregnancy, that procedure is still e~perimental.'~ The patient should be reassured that the IUD does not increase the risk of fetal rnalformation~,~~ but she should also understand that the device does increase her risk of preterm labor. The patient should be instructed to
THE INTRAUTERINE CONTRACEPTIVE DEVICE
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seek prompt medical care if any symptoms associated with intrauterine infection develop because the risk of delivery before 37 weeks gestation is two to four times higher in women with IUDs. The absolute risk of prematurity with IUDs left in situ (regardless of string status) has been reported to range from 18.7%6to 37.5%.42 Missing Tail Strings
The IUD tail strings may not be apparent because they were excessively trimmed, because they have become twisted in the endocervical canal, or because the device has been expelled or perforated in the peritoneal cavity. Nonpregnant women with missing IUD tail strings can easily be evaluated. The first step is to twist a cytobrush inside the cervix to determine whether the strings have inadvertently become tangled within the cervical canal. A uterine sound can be used to probe the uterine canal to detect the base of a partially expelled IUD. Occasionally, an endocervical speculum can be helpful in visualizing the IUD tip or the strings. If these maneuvers are not successful, two options are available. Tread retractors can be passed anteriorly, posteriorly, and laterally to snag the tail strings, or alligator forceps can be used to search within the endometrial cavity and to remove the IUD. A tenaculum must always be placed to stabilize the uterus before any endometrial manipulation. Alternatively, ultrasound studies, especially transvaginal ultrasound, can be performed to locate the IUD. If the IUD is not seen on ultrasound, it has most likely been expelled. Because very unusual sites of migration for perforated IUDs have been described,37 some experts suggest an abdominal radiograph in this situation. If the device has perforated in the peritoneal cavity, surgical removal is necessary because the IUD induces a sterile abscess and can cause bowel damage if left in situ. If the IUD is found to be in the endometrial cavity, it can be removed with alligator forceps (with or without ultrasound guidance). Some clinicians have suggested that IUDs with intrauterine strings can be followed up with serial ultrasound studies as one might manage a tailless IUD. If that choice is made, the ultrasound evaluation needs to be done after the menses because the T-shaped devices move vertically with endometrial growth.15 CONDITIONS FOR REMOVAL
In general, an IUD should be removed when it expires, when a woman no longer qualifies as an IUD candidate (e.g., STD risk, 1 year after menopause, pregnancy desired), when the woman sustains a side effect that cannot be otherwise treated, or when the woman requests removal. All removals must be performed with patient consent. To remove an IUD, the clinician grasps the strings close to the cervical 0s with a sponge forceps or vaginal packing forceps and pulls toward the
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introitus to deliver the device. If significant resistance is felt when traction is placed on the strings, the device may be embedded in the endometrium. A gentle rocking or twisting motion usually frees the device and permits its removal. If reasonable traction does not produce the device or if the strings break, alligator forceps can be introduced into the endometrial cavity to apply pressure directly on the IUD. If there is any suspicion that the device may have perforated the uterine wall, the procedure should be delayed until ultrasound can more completely define the situation. Hysteroscopically directed removal is helpful for removing a deeply embedded device. RETURN TO FERTILITY
The contraceptive effects of the IUD are rapidly reversible; therefore, the IUD is very appropriate as an interval method to help couples space their pregnancies. Pregnancy rates following removal of the copper IUD have been reported in several studies. The median time to planned pregnancy is about 3 month^.^ Younger women had more rapid and more complete (100%) return to fertility. After controlling for age at time of removal, the duration of use had no impact on the time to return to fertility. Wilson47showed that the fertility rates for women who had their IUDs removed for complications were not significantly different from the rates for women who had their IUDs removed to conceive. Wilson's data also reconfirm that the ectopic pregnancy rates after IUD removal are not higher in either group than in the general population." Table 3 summarizes clinical observations of pregnancy following IUD removal. COST-EFFECTIVENESS
Several analyses have verified that the copper IUD is the most costeffective method of birth control currently available in the United States. Analysts have calculated the net benefits of IUD use over a 5-year period Table 3. PREGNANCY FOLLOWING REMOVAL OF AN INTRAUTERINE DEVICE (IUD) Percent Pregnant by Month After Removal Type of IUD
1
3
6
12
Copper IUD* Progesterone-releasing IUDt Levonorgestrel IUD$
27 24 -
69 49
84 67 79-96
89 76 -
-
*Diaz S, Pavez M, Cardenas H, et al: Recovery of fertility and outcome of planned pregnancies after removal of Norplant subdermal implants or copper-IUDs. Contraception 35567, 1987. tErickson R, Mitchell C, Pharriss B, et al: The intrauterine progesterone contraceptive system. Advances in Planned Parenthood 11:167, 1976. $Anderson K, Batar I, Rybo G: Return to fertility after removal of a levonorgestrel-releasing intrauterine device and NovaT. Contraception k 5 7 5 , 1992.
THE INTRAUTERINE CONTRACEITVE DEVICE
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by summing all of the pregnancy-related health care costs and deducting all of the costs associated with the IUD, its insertion, and its failures. In the typical health maintenance organization environment, each copper IUD inserted was shown to save the health care system $14,122 in 5 years.41 NEWER DEVICES
It is expected that the levonorgestrel IUD will become available in the United States within a year. Carrying the brand name Minera (Berlex Laboratories, Wayne, NJ), it will probably be approved for 5 years of use. The device is a T-shaped polyethylene frame with a cylinder of polydimethylsiloxane/ levonorgestrel molded within its stem that releases 20 k g of levonorgestrel per day. Worldwide trials have shown that the first-year typical use failure rate is 0.1%. The mechanisms of action are related to the local application of progestin and are similar to the mechanisms of the progesterone-releasing IUD. The cervical mucus thickens and prevents the passage of sperm into the upper genital tract. The inflammatory changes induced by the plastic frame also contribute to efficacy by acting as a spermicide. The progestin suppresses the endometrium and occasionally suppresses ovulation. The side effects with this device are also influenced by the progestin. Menstrual changes are noted by most users. Women generally experience heavier bleeding in the first cycle but are more likely to experience oligomenorrhea, spotting, or amenorrhea in subsequent cycles. Although the progestin will not reliably suppress ovulation, it can slow the atresia of existing follicles; therefore, an increased risk of functional ovarian cysts is associated with the levonorgestrel IUD. The circulatory levels of progestin are lower than with other progestin contraceptives, thus a few women may complain of bloating or breast tenderness with the levonorgestrelreleasing IUD. This IUD has many attractive features. It does not increase a woman’s risk for PID. It has been shown to be an effective treatment for menorrhagia.20Blood loss is reduced by 86% at 3 months and by 97% after 12 months of use. The levonorgestrel IUD also can be used to protect the uterus from estrogen stimulation in postmenopausal women, especially in women who do not tolerate systemic progestin. A frameless IUD (FlexiGard or Cu-Fix) is used in Scandinavia for nulliparous women with smaller endometrial cavities. It consists of six pledgets of copper with a surface area of 330 mm2 placed in tandem on a polypropylene string that is knotted at both ends. The knot at the top of the string is embedded into the myometrium at insertion, and the strings below the lower knot protrude through the cervix for ongoing monitoring. SUMMARY
The intrinsic appeal of the convenience and effectiveness of the IUD has increased interest in these devices in the United States in recent
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years." Understanding the uniqueness of the Dalkon Shield experience and applying the lessons learned about appropriate candidate selection should continue to reduce any lingering liability concerns. One lawsuit has been filed against the copper IUD in the 12 years that it has been available in the United States. If legislation requiring insurance coverage for IUDs and other prescription contraceptive agents continues to be passed by more states, the use of IUDs will continue to grow. The introduction of new IUDs with different side-effect profiles will expand the number of US women who can and will be interested in using this method of birth control. References 1. Alvarez F, Brache V, Fernandez E, et al: New insights on the mode of action of intrauterine contraceptive devices in women. Fertil Steril 49:768, 1988 2. Atrash HK, Frye A, Hogue CJR Incidence of morbidity and mortality with IUD in situ in the 1980s and 1990s. In Bardin CW, Mishell DR Jr (eds): Proceedings from the Fourth International Conference on IUDs. Boston, Butternorth-Heinemann, 1994, p 76 3. Belhadj H, Sivin I, Diaz S, et al: Recovery of fertility after use of the levomorgesrel20 mcg/d or copper T 380Ag intrauterine device. Contraception 34261, 1986 4. Burkman RT, and the Women's Health Study: Association between intrauterine device and pelvic inflammatory disease. Obstet Gynecol57269, 1981 5. Centers for Disease Control and Prevention (CDC): Current trends: IUD safety. Report of a nationwide physician survey-editorial note-1997. IUD safety. MMWR Morb Mortal Wkly Rep 46:971, 1996 6. Chaim W, Mazor M Pregnancy with an intrauterine device in situ and preterm delivery. Arch Gynecol Obstet 252:21, 1992 7. Chi I: What have we learned from recent IUD studies: A researcher's perspective. Contraception 48:81, 1993 8. Cramer DW, Schiff I, Schoenbaum SC, et al: Tuba1 infertility and the intrauterine device. N Engl J Med 312941, 1985 9. Dajani AS, Taubert KA, Wilson W: Prevention of bacterial endocarditis: Recommendations by the American Heart Association. JAMA 2771794, 1997 10. Daling JR, Weiss NS, Metch BJ, et al: Primary tuba1 infertility in relation to the use of an intrauterine device. N Engl J Med 312:937, 1985 11. Dardano KL, Burkman RT The intrauterine contraceptive device: An often-forgotten and maligned method of contraception. Am J Obstet Gynecol lSl:l, 1999 12. Ebi KL, Pizali RO, Rosenberg M, et al: Evidence against tailstrings increasing the rate of pelvic inflammatory disease among IUD users. Contraception 53:25, 1996 13. El-Habashi M, El-Sahwi S, Gawish S, et al: Effect of Lippes loop on sperm recovery from human fallopian tubes. Contraception 22549, 1980 14. Farley TMM, Rosenberg MJ, Rowe PJ, et al: Intrauterine devices and pelvic inflammatory disease: An international perspective. Lancet 339:785, 1992 15. Fadndes D, Bahamondes L, F a h d e s A, et al: T-shaped IUDs move vertically with endometrial growth and involution during the menstrual cycle. Contraception 57:413, 1998 16. Grafenberg E: An intrauterine contraceptive method. In Sanger M, Stone HM, (eds): The Practice of Contraception: Proceedings of the 7th International Birth Control Conference, Zurich, Switzerland. Baltimore, Williams & Wilkins, 1930, p 33 17. Grimes DA, Schulz KF: Prophylactic antibiotics for intrauterine device insertion: A metaanalysis of the randomized controlled trials. Contraception 6057, 1999 18. Huber SC, Piotrow PT, Orlans FB, et al: IUDs reassessed: A decade of experience. Popul Rep B 3(2):2148, 1975 19. Hucke J, Campo RL, Kozlowski P, et al: Experience with hysteroscopy or ultrasound-
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controlled removal of an intrauterine spiral with no visible thread in early pregnancy. Geburtshilfe und Frauenheilkinde 51:31, 1991 20. Irvine GA, Campbell-Brown MB, Lumsden MA, et al: Randomised comparative trial of the loevnorgestrel intrauterine system and norethisterone for treatment of idiopathic menorrhagia. Br J Obstet Gynaecol 105:592, 1998 21. Ishihama A Clinical studies on intrauterine rings, especially the present state of contraception in Japan and the experiences in the use of intrauterine rings. Yokohama Medica Bulletin 10:89, 1959 22. Kjos SL, Ballagh SA, La Cour M, et al: The copper T380A intrauterine device in women with type I1 diabetes mellitus. Obstet Gynecol 841006, 1994 23. Lee NC, Rubin GL, Borucki R The intrauterine device and pelvic inflammatory disease revisited: New results from the Women’s Health Study. Obstet Gynecol 721, 1988 24. Mishell DR Jr, Bell JH, Good RG, et al: The intrauterine device: A bacteriologic study of the endometrial cavity. Am J Obstet Gynecol 96:119, 1996 25. Moyer DL, Rimdusit S, Mishell DR Jr: Sperm distribution and degradation in the human female reproductive tract. Obstet Gynecol 352331, 1970 26. Nelson AL: Intrauterine device practice guidelines: Medical conditions. Contraception 58:59S, 1998 27. Oppenheimer W Prevention of pregnancy by the Grafenberg ring method: A reevaluation after 28 years’ experience. Am J Obstet Gynecol78446, 1959 28. Ota T A study on birth control with an intrauterine instrument. Japanese Journal of Obstetrics and Gynecology 17210, 1934 29. Potts DM, Champion CB, Kozuh-Novak M, et al: IUDs and PID: A comparative trial of strings versus stringless devices. Adv Contracept 7231, 1991 30. Pust K Ien vrauchbarer frauenschurtz. Deutsche Med Wochenschrift 49:952, 1923 31. Richter R Ein mittel zur verhurung der kinzeption. Dtsch Med Wochensch 35:1525, 1909 32. Riviera R, Yacobson I, Grimes D: The mechanism of action of hormonal contraceptives and intrauterine contraceptive devices. Am J Obstet Gynecol 118:1263, 1999 33. Sagiroglu N: Phagocytosis of spermatozoa in the uterine cavity of women using intrauterine device. Int J Fertil 16:1, 1971 34. Segal SJ, Alvarez-Sanchez F, Adejuwon CA, et al: Absence of chorionic gonadotropin in sera of women who use intrauterine devices. Fertil Steril44214, 1985 35. Skjeldestad FE, Halvorsen LE, Kahn H, et al: IUD users in Norway are at low risk for genital C. trachomatis infection. Contraception 54209, 1996 36. Speroff L, Damey PD: A Clinical Guide for Contraception, ed 2. Baltimore, Williams & Wilkins, 1996, p 191 37. Stutz JA, Wilkinson SA: Psoas abscess: An unusual complication of an intrauterine contraceptive device. Br J Obstet Gynaecol 106:177, 1999 38. Tatum HJ, Beltran RS, Ramos R, et al: Immediate postplacental insertion of GYNE-T 380 and GYNE-T 380 postpartum intrauterine contraceptive devices: Randomized study. Am J Obstet Gynecol 175:1231, 1996 39. Tatum HJ, Schmidt FH, Phillips D, et al: The Dalkon Shield controversy: Structural and bacteriological studies of IUD tails. JAMA 231:711, 1975 40. Treiman K, Liskin L, Kols A, et al: IUDs-an update. Popul Rep B 23(6):1-35, 1995 41. Trussell J, Leveque JA, Koenig JD, et al: The economic value of contraception: A comparison of 15 methods. Am J Public Health 85:494, 1995 42. UK Family Planning Research Network Pregnancy outcome associated with the use of IUDs. Br J Fam Plann 15:7, 1989 43. United Nations Development Programme/United Nations Population Fund/ World Health Organization/ World Bank, Special Programme of Research, Development and Research Training in Human Reproduction: Long-term reversible contraception: Twelve years of experience with the TCu380A and TCu220C. Contraception 56341, 1997 44. Walsh T, Grimes D, Frezieres R, et al: Randomised controlled trial of prophylactic antibiotics before insertion of intrauterine devices. Lancet 351:1005, 1998 45. White MK, Ory HW, Rooks JB, et al: Intrauterine device termination rates and the menstrual cycle day of insertion. Obstet Gynecol 55220, 1980
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46. Wilcox AJ, Weinberg CR, Armstrong EG, et al: Urinary human chorionic gonadotropin among intrauterine device users: Detection with a highly specific and sensitive assay. Fertil Steril 47265, 1987 47. Wilson JC: A prospective New Zealand study of fertility after removal of copper intrauterine devices for contraception and because of complications: A four-year study. Am J Obstet Gynecol 160391, 1989 48. World Health Organization: Improving Access to Quality Care in Family Planning: Medical Eligibility Criteria for Contraceptive Use, vol. 76. Geneva, World Health Organization, 1996, p 27 49. World Health Organization: Mechanism of Action, Safety and Efficacy of Intrauterine Devices. Report of a WHO Scientific Group. Technical Report Series 753. Geneva, World Health Organization, 1987, p 1 50. Zipper JA, Tatum HJ, Medel M, et al: Contraception through the use of intrauterine metals. I. Copper as an adjunct to the "T" device: The endouterine copper "T." Am J Obstet Gynecoll 109:771, 1971
Address reprint requests to Anita L. Nelson, MD Harbor-UCLA Medical Center 1000 W Carson Street, Box 474 Torrance, CA 90509-2910 e-mail: AnitaNelsonWHCQearthlink.net