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FERTILITY AND STERILITY

Vol. 56, No.1, July 1991

Copyright © 1991 The American Fertility Society

Printed on acid-free paper in U.S.A

Ovulation induction with pulsatile gonadotropin-releasing hormone: technical modalities and clinical perspectives

Marco Filicori, M.D. Carlo Flamigni, M.D. Maria Cristina Meriggiola, M.D. Graciela Cognigni, M.D.

Alessandro Valdiserri, M~D. Paola Ferrari, B.Sc. Elisabetta Campaniello, M.D.

Center for Chronobiology of Reproduction and Reproductive Medicine Unit, Department of Obstetrics and Gynecology, University of Bologna, Bologna, Italy

Disordered menstrual cyclicity and anovulation are common complaints among infertile patients. Thus, it is not surprising that ovulation induction is a widely used therapeutic tool for treating patients referred to reproductive endocrinology and infertility clinics. Several medications have proved highly effective in stimulating ovulation and improving the pattern of endocrine secretion of the menstrual cycle. Clomiphene citrate (CC) was introduced for clinical use almost 30 years ago and is still commonly used because of its ease of administration and safety. The apparent rate of ovulation is high in selected patients, and the risk of side effects and complications (ovarian hyperstimulation, multiple pregnancies) is limited. 1 Unfortunately, CC is not effective in profound hypogonadotropic hypogonadism, and the pregnancy rate (PR) achieved in other disorders is relatively low considering the elevated number of apparent ovulations. Human menopausal gonadotropins (hMG) are effective in most ovulatory disorders except primary gonadal failure. However, the high potential risk of ovarian hyperstimulation and of multiple pregnancy2,3 renders close endocrine and ultrasound (US) monitoring an absolute requirement for the management of patients receiving hMG; thus, safe clinical availability of this potent pharmacological tool is limited to offices and units in which appropriate monitoring can be conducted. The hypothalamic decapeptide gonadotropin-releasing hormone (GnRH) was isolated and synthesized in 1971 by Amoss et al. 4 and Schally et al. 5 The potential interest and usefulness of this hormone was immediately recognized, as attested by

the award of the 1977 Nobel Prize to these investigators. Unfortunately, early clinical trials failed to achieve satisfactory results in terms of ovulation induction capacity.6 The understanding of the close linkage between the physiological pattern of pulsatile secretion of hypothalamic and pituitary hormones and GnRH stimulatory ability led to the fundamental studies of Knobil's group in the nonhuman primate 7 that firmly established the central role of the pulsatile mode of GnRH administration for the stimulation of pituitary gonadotropins and ovulation. This basic work was soon followed by the reports of Hoffman et al. B and Crowley et al. 9 that demonstrated the great clinical efficacy of pulsatile GnRH for the treatment of male and female hypogonadotropic hypogonadism (Fig. 1); the first pregnancies achieved with pulsatile GnRH ovulation induction were reported in 1980 by Leyendecker et al. lO Over 10 years after these early studies, pulsatile GnRH is now widely available and used as a safe and effective method for ovulation induction in several countries worldwide. This paper will review endocrine, clinical, and technical aspects of this form of treatment in anovulatory infertility.

Several biological features render pulsatile GnRH unique among the different methods of ovulation induction. The clinical peculiarities of hMG and pulsatile GnRH can be easily explained if the endocrine characteristics of each ovulation induction method are appreciated.

Vol. 56, No.1, July 1991

Filicori et al.

MAIN CHARACTERISTICS OF PULSATILE GnRH OVULATION INDUCTION

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Figure 1 First demonstration in the human that pulsatile GnRH can restore the endocrine pattern of the normal menstrual cycle in subjects with hypogonadotropic hypogonadism. The graph shows the daily concentrations of LH, FSH, E 2 , and P during the SC administration of 25 ng/kg of GnRH at 120-minute intervals in a patient with Kallmann's syndrome. (From Crowley and McArthur. 9 Reprinted by permission of the publisher).

When the gonadotropin secretory pattern of the GnRH-induced menstrual cycle is analyzed, several similarities with the normal menstrual cycle become evident (Fig. 3). As in spontaneous cycles, FSH concentrations are elevated only in the early follicular phase and decline thereafter, whereas LH levels progressively increase until ovulation. Thus, the physiological events leading to the maturation and ovulation of a single dominant follicle are preserved. The endocrine dynamics of the midcycle preovulatory surge in GnRH cycles are also noteworthy. Preovulatory estradiol (E 2) levels peak at 300 to 450 pg/mL,12 thus indirectly confirming that a single ovarian follicle has achieved maturity. The midcycle LH surge occurs spontaneously after the estrogen (E) peak and a modest increment of progesterone (P) concentrations. These endocrine events faithfully recapitulate the preovulatory dynamics of the normal menstrual cycle and assure that the ovulation signal occurs when optimal follicular maturity is achieved and not at a time artificially chosen by the physician. Furthermore, the existence of a spontaneous gonadotropin surge enables withholding the

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SPONTANEOUS CYCLE

When hMG is given to hypogonadotropic subjects (Fig. 2) follicle-stimulating hormone (FSH) levels are elevated throughout the follicular phase and peak before ovulation. l l This pattern is in stark contrast to the endocrine events ofthe normal menstrual cycle when elevated FSH levels are present in the perimenstrual transition (late luteal and early follicular phase) and decline thereafter until just before the preovulatory surge. Although luteinizing hormone (LH) levels progressively increase across the follicular phase of the spontaneous menstrual cycle, LH is usually low in the hMG-induced follicular phase. l l The dynamic interplay between LH and FSH levels in spontaneous cycles provides an optimal stimulus for follicular recruitment at first and for the selection of the dominant follicle later; conversely, the tonically elevated FSH levels typical of the hMG-induced follicular phase usually result in exuberant folliculogenesis and may predispose patients to develop multiple conception and ovarian hyperstimulation. A remarkable characteristic of pulsatile GnRH administration is that during treatment the pituitary retains its ability to modify gonadotropin output in response to negative and positive feedback stimuli. 2

Filicori et al.

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DAYS OF TREATMENT Figure 2 Daily gonadotropin and gonadal steroid levels throughout one normal spontaneous menstrual cycle (left panels) and during hMG ovulation induction in a patient with pituitary hypogonadotropic hypogonadism (right panels). Human menopausal gonadotropins (1 to 2 ampules per day) was administered until VS demonstrated the development of one dominant follicle and plasma E2 achieved levels of about 800 pg/mL. Ovulation was induced with 5,000 V hCG and CL function was maintained with 2,000 V hCG at 3-day intervals.

Fertility and Sterility

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DAYS OF CYCLE Figure 3 Daily gonadotropin and gonadal steroid levels throughout one normal spontaneous menstrual cycle (the same as Fig. 2; left panels) and during pulsatile GnRH ovulation induction in a patient with hypothalamic primary amenorrhea (right panels). Notice that the E2 scale of the GnRH cycle is half that of the E2 scale of the hMG cycle of Figure 2.

chemical signs of excessive ovarian stimulation (we termed this phenomenon ovarian overstimulation in contrast to hyperstimulation), such as enlarged ovaries and high E levels may indeed develop in a few patients,14-20 none of the complications that often require hospital admission after hMG ovulation induction (e.g. oliguria, ascites) have been reported to occur, and the incidence of multiple pregnancy is limited. Furthermore, even continuation of pulsatile GnRH (hCG should be avoided) does not lead to serious problems. 12 Close endocrine monitoring with daily E determinations is superfluous with this procedure, thus rendering pulsatile GnRH the perfect candidate for outpatient ovulation induction. 21 TECHNICAL ASPECTS OF PULSATILE GnRH OVULATION INDUCTION Delivery Systems

preovulatory administration of human chorionic gonadotropin (hCG). This factor contributes to the safety of GnRH-induced cycles, considering that hCG administration precipitates clinical ovarian hyperstimulation when excessive dosages of hMG are given. The luteal phase of GnRH-induced cycles also bears striking similarities to one of the spontaneous cycles (Fig. 3). Estradiol and P levels are normally elevated, and a late luteal phase rise of FSH is present; if pulsatile GnRH is continued for a second consecutive cycle, the normal dynamics ofthe lutealfollicular transition ensueP The duration ofthe luteal phase of GnRH cycles is usually longer than normal by a couple of days,12 but spontaneous menses occur in nonpregnant cycles in spite of continued GnRH stimulation. Human chorionic gonadotropin can be safely used to support the corpus luteum (CL). Pelvic US performed in the course of pulsatile GnRH ovulation induction shows that maturation of a single dominant follicle occurs in the majority of cycles;12 furthermore, the development of numerous (>3) large follicles (>15 mm diameter) is rare. Because of these endocrine and morphological characteristics, the occurrence of frank ovarian hyperstimulation is practically nonexistent when pulsatile GnRH is employed; although US and bio-

The need for an intermittent and timed mode of drug administration renders GnRH fundamentally different from most other treatments employed in reproductive medicine. Although some initial studies were carried out with GnRH given by hospital personnel during ward admission or using patient selfadministration,22 soon it became evident that wide scale use of this technique required the development of reliable automatic infusion devices. Several automatic pumps are now available that can administer GnRH at the required regimens for ovulation induction. These delivery systems include the pump developed by Sutherland et a1. 23 (the "Mill Hill" pump) and models marketed by Autosyringe Inc. (Hookset, NH). However, the most widely employed pump for pulsatile GnRH delivery is the Zyklomat produced by Ferring GmbH, in Kiel, Germany; in the United States, the same pump is marketed as Lutrepulse by Ortho Pharmaceutical Corporation (Raritan, NJ). Zyklomat is a microchip-controlled peristaltic pump that can deliver 25 or 50 ~L boluses of GnRH solution at 90- or 120-minute intervals. Future models of this pump should permit institution of a greater range of frequency and dose regimens. Within the Zyklomat pump, the GnRH solution is contained in a special 10 mL reservoir, thus allowing 7 to 10 days of uninterrupted drug administration. Most pumps used for pulsatile GnRH administration are relatively shock-resistant and will withstand numerous ovulation induction cycles. However, malfunctions may occur when the electric circuitry is inadvertently exposed to fluids by the

Vol. 56, No.1, July 1991

Filicori et al.

Ovulation induction with pulsatile GnRH

3

patient (e.g., when taking a bath) or because of spillage of the drug solution. Nevertheless, such damages are not dangerous for the patient and will only cause temporary suspension of the stimulation; if the pump is substituted and treatment reinstituted within a few hours, ovulation can still be achieved. Because GnRH overdosage is harmless, no direct danger can derive from excessive GnRH administration from a defective pump; however, it is possible that such a regimen may excessively stimulate folliculogenesis. Route

otropin secretion than the SC route. 29-32 Although the IV route appears to be more effective when the two methods of administration were compared in the same study,33,34 most groups that employ SC GnRH have reported high ovulatory rates and PRS14,18,25; nevertheless, even those centers that routinely employ SC GnRH resort to the IV route in resistant patients. 25 Larger bolus dosages of GnRH are needed when the SC route is used and significant amounts of the drug solution are discarded because the tubing with the SC needle is more frequently changed. Therefore, the consumption of larger amounts of GnRH (and thus a higher cost) should be expected when the SC route is employed.

Gonadotropin-releasing hormone is usually administered intravenously (IV) or subcutaneously (SC). Intranasal (IN) pulsatile GnRH self-administration has been attempted24 ; however, the lack of consistency of nasal absorption and the impossibility of continuing IN administration during sleep seriously limit the applicability of this approach. Subcutaneous GnRH administration is considered simpler and safer than IV because the infusion needle can be applied directly by the patient and no systemic septic complications should occur.25 However, the IV route, if properly positioned and maintained, is usually associated with a remarkably low rate of septic complications12 and of positive blood cultures. 26 Although the development of modest local venous inflammation may occur,21,27,28 this problem promptly regresses when the IV insertion is moved to a different area of the arm. The low incidence of serious septic complications experienced by the centers that use the Zyklomat/Lutrepulse system may, in part, be related to the relatively long period of uninterrupted IV administration allowed by this setup (7 to 10 days); other systems that need more frequent refills may be associated with a higher risk of accidental contamination. In our unit, we prefer the IV route, and we use an Angio-Set (20 g, 2.5 cm) IV catheter (Deseret Medical, Sandy, UT); the site of insertion of the IV set is protected with the Tegaderm transparent dressing (3M Medical-Surgical Division, St. Paul, MN). Heparin (100 U/mL) is added to the GnRH solution when the IV route is employed. We usually have no problems keeping this setup in place for several consecutive weeks. We found an excellent acceptance of the IV route by our patients, and the occasional phlebitis is dealt with by simply changing the insertion of the IV catheter. Antibiotic therapy is only employed in the rare cases when fever appears. The IV route is associated with a more precise reproduction of the physiological pattern of pulsatile GnRH and gonad-

Gonadotropin-releasing hormone for therapeutic use (Lutrelef; Ferring GmbH or Lutrepulse; Ortho Pharmaceutical Corporation) is supplied in vials containing either 0.8 mg or 3.2 mg of drug; when properly reconstituted with the supplied solvent, a GnRH concentration of 5 f.Lg or 20 f.Lg per 50 f.LL of solution is achieved. Setting the Zyklomat/Lutrepulse pump bolus volume at 25 or 50 f.LL permits delivery of 2.5, 5.0, 10.0, or 20.0 f.Lg of GnRH at each pump activation. Other GnRH concentrations can be obtained by changing the amount of solvent. The GnRH supplied for diagnostic purposes by other pharmaceutical companies may also be used; however, because this GnRH is usually packaged in 100 f.Lg per ampule formulations, its use requires the cumbersome combination of numerous ampules of product and may lead to an increased risk of contamination. A wide range of GnRH dosages have been employed for pulsatile GnRH ovulation induction (Tables 1 and 2). As previously indicated, larger GnRH dosages are needed for the SC route. Although successful induction of ovulation can be achieved with GnRH dosages as low as 1 f.Lg/bolus,9,39 early studies employed 10 to 20 f.Lg/bolus 35,36; it is now evident that these high IV dosages may be associated with a greater risk of multiple conception.48 Santoro et aI.42 showed that 25 ng/kg (about 1.5 f.Lg/bolus) of IV GnRH not always succeeds in stimulating ovulation in hypogonadotropic hypogonadism, whereas 100 ng/kg (about 6 f.Lg/bolus) may be slightly excessive (Table 1). It was recently demonstrated that a GnRH dose/bolus of 2.5 f.Lg every 60 minute IV is fully capable of restoring the endocrine pattern of the normal menstrual cycle in patients with different forms of hypogonadotropic hypogonadism. 12 At present, in most centers the standard starting GnRH

Ovulation induction with pulsatile GnRH

Fertility and Sterility

4

Filicori et al.

Gonadotropin-Releasing Hormone Dose

Table 1

Pulsatile GnRH Ovulation Induction in Hypogonadotropic Hypogonadism

GnRH dose/ bolus

Bolus interval

No. of patients

No. of cycles

Ovulatory cycles

Ovulatory rate/cycle

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1 2 6 7 27 3 24

1 2 6 12 40 5 68

1 2 5 12 32 5 NAb

100 100 83 100 80 100 NA

3 26

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8 3 14 5

23 3 36 15 10 20 18 140 189 30 65

20 3 30 13 8 20 16 123 167 28 59

87 100 83 87 80 100 89 88 88 93 91

5 2 13 4 2 6 3 20 59 10 16

22 67 36 27 20 30 17 14 31 33 25

683.

544

89

183

27

Route

min

Crowley et ai., 19809 Leyendecker et aI., 198010 Leyendecker et aI., 198036 Skarin et ai., 198216 Berg et aI., 198336 Hurley et aI., 198337 Leyendecker and Wildt, a 198336 Miller et aI., 198339 Seibel et ai., 198340 Hurley et ai., 198314 Caruso et aI., 198541 Santoro et aI., 198642 Amodeo et aI., Blunt and Butt, 198817 Homburg et aI., 198925 Filicori et aI., 199112 198743

25 ng/kg 15 to 20 /log 10 to 15 /log 20/log 20/log 5 to 10/log 2.5 to 20/log 1to5/1og 12 to 20 /log 5 to 15 /log 2.5 to 12.5 /log 25 ng/kg 100 ng/kg 5 to 20 /log >10/log 15/1og 2.5/1og 5/1og

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Pregnancies

PR/cycle

%

}

Totals a The 68 cycles reported by Leyendecker and Wildt were not considered to calculate the overall ovulatory rate because the number of ovulatory cycles was not provided.

dose per bolus employed for IV therapy is 5 IJ,g; this dose is usually increased to 10 to 20 IJ,gjbolus when no response occurs within 10 to 15 days. Frequency of GnRH Administration

18 8 28 56 63 273

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100

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blunted51 ; increasing the GnRH dose partly corrected these derangements. When the every-60minute and the every-90-minute frequencies of GnRH administration were compared, it was determined that although no major clinical differences seemed to exist, the every-60-minute frequency resulted in a more physiological reproduction of the endocrine features of the normal menstrual cycle. 52 Thus, although a 90-minute interval of GnRH administration is clinically acceptable, a 60-minute interval is more desirable and may result in further optimization of treatment outcome.

In most published studies on the use of pulsatile GnRH in females, the frequency of hormone administration was set at one bolus every 90 minutes; this frequency of administration is also the one advised by pharmaceutical companies, and most centers have adopted it. However, this frequency was chosen based on early data on the pattern of spontaneous episodic LH secretion in the follicular phase of the normal menstrual cycle. 49 Later, more extensive and detailed studies that employed a faster blood sampling frequency (a procedure that increases resolution and thus improves pulse identification) determined that the frequency of normal episodic LH secretion in the midfollicular and late follicular phase is close to one pulse every hour. 50 Furthermore, it was recently shown that when GnRH is administered to patients with primary hypogonadotropic amenorrhea (i.e., subjects with no endogenous GnRH secretion) at a nonphysiological frequency of one pulse every 120 minutes, ovulation rates are reduced and the midcycle LH surge may be severely

Continuing pulsatile GnRH after ovulation will result in normal CL function 7,12 even though a faster than normal53 frequency of GnRH administration is employed. This regimen usually extends CL life span by a few days, but menses occur spontaneously unless the patient is pregnant. The use of pulsatile GnRH in the luteal phase permits an early detection of conception by measuring plasma i3-hCG when menses are delayed by no more than 2 to 3 days. Administration of exogenous hCG after ovulation (usually 1,000 to 2,000 U at 3-day intervals for 3 times) appears to be equally effective in supporting,

Vol. 56, No.1, July 1991

Filicori et aI.

Luteal Phase Support

Ovulation induction with pulsatile GnRH

5

CL function,54 although these two regimens have never been compared. The use of hCG is less expensive and frees up the pump for other patients; however, when consecutive back-to-back cycles are planned in hypogonadotropic patients, continued pulsatile GnRH is preferable. Exogenous P administration can alternatively provide endometrial support,55 but this approach has not been used extensively. Treatment Monitoring

In contrast to hMG therapy, rapid daily E determinations are not needed during pulsatile GnRH ovulation induction. Pelvic US, although not essential, can be useful for the occasional detection of multiple folliculogenesis that may lead to multiple conception. Pelvic US is usually performed at 3 to 4-day intervals in the follicular phase or more often after the appearance of follicles> 15 mm in diameter; vaginal probes provide an improved visualization of the ovarian structure. The assessment of cervical mucus score is of limited value and inconvenient for the patient; conversely, basal body temperature charts are extremely useful to confirm ovulation and to assess luteal phase quality at the end of treatment. Finally, rapid home measurements of urinary LH with enzyme immunoassays can be useful to predict ovulation and thus target intercourse or artificial insemination.

sponse to pulsatile GnRH was high (89% to 95% per treatment cycle), and pregnancy ensued in 30% of subjects. Pulsatile GnRH administration in these patients resulted in an almost perfect restoration of the endocrine and morphological features of the normal menstrual cycle (Fig. 3). The uterus and ovaries were small at baseline but rapidly grew and achieved normal size; thus, E pretreatment to increase uterine volume is not required. It had been suggested that patients with such a profound form of hypo gonadotropic hypogonadism may be resistant to pulsatile GnRH administration and that high GnRH doses (~15 Jlgfbolus) would be required. 3s However, this recent studyl2 demonstrated that a dosefbolus as low as 2.5 Jlg is fully adequate to restore normal reproductive hormone secretion and ovulation in these patients. Finally, the occurrence of multiple pregnancy is rare in these patients, probably in relation to the lack of pituitary gonadotroph priming at the outset of treatment. Other Forms of Hypogonadotropic and N ormogonadotropic Anovulation

Patients with this disorder usually present a virtually absent endogenous GnRH secretion; primary pituitary disorder is rare, and normal gonadotropin secretion is restored by the administration of exogenous pulsatile GnRH in the majority of cases. In some of these patients, defective GnRH secretion is associated with atrophy of the olfactory bulbs and a deficient sense of smell (Kallmann's syndrome). Patients with primary hypo gonadotropic amenorrhea represent a unique experiment of nature in which to study the effect of different regimens of GnRH administration without the confounding influence of endogenous GnRH, and, as such, have been used by different investigators. 5l ,56-59 The treatment of 30 patients with primary hypogonadotropic amenorrhea for a total of 40 cycles was recently reported l2 ; the ovulatory rate in re-

Less severe forms of hypogonadotropic menstrual disorders (secondary amenorrhea, oligomenorrhea) are associated with decrements in the frequency and/or amplitude 56,60 of LH peaks. In some patients, menstrual derangements may be present in spite of normal mean gonadotropin levels; nevertheless, pulsatile LH release is usually altered. 56 Thus, it is not surprising that in most of these patients restoration of a physiological pattern of pulsatile LH secretion with exogenous GnRH results in the resumption of ovulation and fertility. Pulsatile GnRH is highly effective in inducing ovulation in these subjects. In the 683 cycles in 273 patients reported by the articles shown in Table 1, the overall ovulatory rate per cycle was 89%, whereas pregnancy was achieved in 27% of treatment cycles. In many of these patients existing, albeit deranged, hypothalamic GnRH secretion results in the priming of the pituitary gonadotroph. Thus, exogenous GnRH stimulation often causes brisk gonadotropin secretion; follicular phase LH and FSH levels are significantly higher than in normal spontaneous cycles. l2 This excessive gonadotropin secretion may result in the maturation of more than a single dominant ovarian follicle: the occurrence of multiple pregnancy is highest among hypogonadotropic patients (Table 3). When hypo gonadotropic anovulation is caused by hyperprolactinemia, pulsatile GnRH administration will restore ovulation and normal gonadotropin

Ovulation induction with pulsatile GnRH

Fertility and Sterility

RESULTS OF PULSATILE GnRH IN DIFFERENT OVULATORY DISORDERS Primary Hypogonadotropic Amenorrhea

6

Filicori et a1.

Table 2

Pulsatile GnRH Ovulation Induction in peos GnRH dose/bolus

Bolus interval

Route

No. of patients

No. of cycles

Ovulatory cycles

Ovulatory rate/cycle

5 74 2 0 99 2 2 18 38

83 87 17

25 ng/kg 5 to 40 ILg 20 to 40 ILg 5 to 40 ILg 15 ILg 5 ILg

Filicori et aI., 199112

5 ILg

90 60 to 120 120 to 400 90 90 90 60

IV IV se IV Se,IV IV

4 5 47 9

IV

51

• Some patients received ee supplementation. b Pre-A, without GnRH-a pretreatment.

and steroid secretion. 6H3 This finding indirectly confirms that deranged reproductive function in this disorder depends upon altered hypothalamic GnRH secretion. Polycystic Ovary Syndrome

The frequency and/or amplitude of LH pulses is already excessive in many polycystic ovary syndrome (PCOS) patients.54,65 Consequently, further gonadotropin stimulation with pulsatile GnRH cannot be expected to be very effective in this disorder; the ovulatory rate does not exceed 40% to 50%, and pregnancy is only achieved in up to 16% of cycles (Table 2). Higher ovulatory rates reported earlier7,44 were not confirmed in later studies. 12,25,46,47 Furthermore, to correctly assess treatment outcome, PCOS patients should be carefully selected as subjects with multifollicular ovaries and low LH and testosterone (T) levels respond normally to pulsatile GnRH.66 Intravenous pulsatile GnRH and supplemental CC seem to improve the response in PCOS. 67 We tested a different approach that enables correction of some of the deranged pathophysiological characteristics associated with PCOS by inducing a reversible hypogonadotropic condition before the initiation of pulsatile GnRH. 12,19,66 Ovulation induction was started after a 6 to 8-week period of pituitaryovarian suppression with a GnRH analog (GnRH-a, Buserelin acetate, 300 JLg, SC, twice a day). Follicular phase gonadotropin and T levels in postanalog cycles were reduced, whereas the FSH/LH ratio was increased68 (Fig. 4). An overall improvement of the endocrine picture was achieved with a pattern of gonadotropins and gonadal steroids that resembled the one elicited in hypo gonadotropic hypogonadism19 (Fig. 5). Ovulation was obtained in 75% to Vol. 56, No. I, July 1991

PR/cycle

%

min

Ory et aI., 1985" Burger et ai., 198627 Hurwitz et ai., 198645 Wilson et aI., 198846 Homburg et ai., 198925 • Surrey et aI., 198947

Pregnancies

4 11

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51 22 28 43 76

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80% of postanalog cycles; this rate was further increased to about 90% (and thus to the level of hypogonadotropic subjects) in nonobese PCOS patients. 12 Similar improvements in the endocrine dynamics of the menstrual cycle induced with pulsatile GnRH after GnRH -a suppression were later reported by Surreyet a1. 47 in nine CC-resistant PCOS women; however, the ovulatory rate was only marginally increased in this study. The positive effect of this regimen in the immediate postanalog period probably depends on the establishment of a window of increased susceptibility to pulsatile GnRH because of lower intraovarian androgens and to more physiological gonadotropin levels (particularly FSH prevalence). Such a window is lost after about 2 weeks from discontinuation of analog suppression: when a second consecutive pulsatile GnRH cycle is attempted, the endocrine and clinical outcome is less favorable 19 (Fig. 5). OBSTETRICAL OUTCOME

The outcome of pregnancies obtained with pulsatile GnRH in hypogonadotropic and PCOS patients in three large studies 12,25,48 is shown in Table 3. These articles reported 318 pregnancies: 39 (12%) were multiple, whereas 51 (16%) underwent spontaneous abortion. The incidence of these complications thus appears to be markedly lower than after hMG ovulation induction2,3; furthermore, only one quadruplet69 and a handful of triplet pregnancies25,38,48,7o-72 have ever been reported with pulsatile GnRH. Thus, in the majority of cases only twins will occur, a degree of multiparity that is considered acceptable by many infertile couples and that only moderately increases the obstetrical risk. A closer analysis of these results indicates that most multiple pregnancies occurred among hypoFilicori et al.

Ovulation induction with pulsatile GnRH

7

gonadotropic patients (Table 3). This complication appears to be related to the functional status of the hypothalamic-pituitary axis and to pre-existing pituitary priming. Multiple pregnancy occurs mostly in hypogonadotropic states characterized by a partial GnRH deficiency (secondary amenorrhea, oligomenorrhea); conversely, total absence of endogenous GnRH secretion, as present in patients with primary hypo gonadotropic amenorrhea, is associated with virtually no risk of multiple conception. 12 The multiple pregnancy risk is lower when conception takes place in consecutive cycies,48 i.e., when excessive pituitary priming has been controlled by the effect of endogenous P. Finally, pituitary priming and thus the possibility of excessive follicular phase gonadotropin and gonadal stimulation can be abolished by pretreating hypogonadotropic patients with a GnRH-a (Fig. 6). When this approach was applied to PCOS and selected hypo gonadotropic patients, no multiple pregnancies ensued,12 suggesting that this regimen may be useful to further reduce the risk of this complication of GnRH ovulation induction. The GnRH dose employed is also an important variable; large GnRH dosages per bolus are associated with a higher incidence of multiple pregnancy,12,42 and a relationship exists between the GnRH dose employed and the occurrence of multiple folliculogenesis. 48 Fewer multiple pregnancies are likely to occur when an IV GnRH dose per bolus < 5 Jlg is employed. 12,48 The incidence of abortion after pulsatile GnRH in hypogonadotropic hypogonadism (12%) appears

Table 3

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DAYS Figure 4 Gonadotropin, E 2 , and T levels in the 1st week of pulsatile GnRH ovulation induction in PC OS patients. Pre-A cycles were without GnRH-a pretreatment, whereas post-A cycles were done in the same patients immediately after pituitary gonadal suppression with buserelin acetate (see text for details). Notice the highly significant reduction of LH and T levels and the increment of the FSH/LH ratio in post-A cycles. *, P < 0.05; P < 0.01. (From Filicori et al. 67 Reprinted by permission of the publisher).

*,

to be within the range of spontaneous pregnancy (Table 3); in contrast, PCOS patients are exposed to an elevated risk of this complication (probably >40%) .12,25 This finding was not confirmed by Braat

Obstetrical Outcome of Pulsatile GnRH Ovulation Induction in Three Recent Large Studies

Hypogonadotropic hypogonadism Total pregnancies Multiple pregnancies Spontaneous abortions Early (%)e Late (%)" PCOS Total pregnancies Multiple pregnancies Spontaneous abortions Early (%)e Late (%)"

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59 b 4 (7)d 11 (19) 12 7

161 28 (17) 16 NAt 10

30 3 (10) 12 (40) 33 7

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Filicori et aI., 1991 12

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246 35 (14) 29 (12)

19 h 1 (5) 8 (42)

72 4 (6) 22 (31)

26 c

Only term pregnancies. Excluding organic pituitary diseases and including low weight. c Including primary amenorrhea. d Values in parentheses are percents.

e Early pregnancy loss (within 4 weeks from ovulation). t NA, not available. "Miscarriage (after 4 weeks from ovulation). h Fourteen pregnancies were achieved after GnRH-a suppression.

Ovulation induction with pulsatile GnRH

Fertility and Sterility

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Figure 5 Daily gonadotropin and gonadal steroid levels during three cycles of pulsatile GnRH (5 /-tg every 60 minutes) ovulation induction in a PCOS patient. Notice the excessive LH levels, the deranged steroid levels, and anovulation in the first cycle done without GnRH-a pretreatment (left panels). A more normal appearing endocrine response and ovulation occurred in the first postanalog cycle (middle panels). Continuation of pulsatile GnRH for a second consecutive postanalog cycle (right panels) was associated with a deterioration of the endocrine pattern and anovulation. (From Filicori et al. ' • Reprinted with permission of the publisher).

CONCLUSIONS

et a1. 48 who found a low 9% abortion rate in PCOS in their large multicenter study; however, these investigators only considered abortions occurring after at least 4 weeks from the time of conception. When the same limit was applied to the data of Homburg et al.,25 a 7% abortion rate resulted; although our data12 were not analyzed in relation to the duration of pregnancy, we generally agree that the majority of spontaneous abortions in PCOS tend to occur in the early stages of embryo development. The apparently low multiple pregnancy rate in PCOS, in spite of the brisk hormonal and ovarian response frequently encountered in these patients,72 may also be related to the elevated occurrence of early miscarriage (Le., before US can assess embryo number). Excessive follicular phase LH levels 73 or CL dysfunction 12 has been suggested as potential pathogenetic mechanisms of spontaneous abortion in PCOS, but the exact cause of this complication has not been yet firmly established.

Use of pulsatile GnRH achieves a level of clinical success comparable with that of hMG ovulation induction without any danger of ovarian hyperstimulation and with limited risks of multiple pregnancy. Specific regimens such as low-dose pulsatile GnRH and GnRH-a pretreatment further reduce the incidence of multiple pregnancy in hypogonadotropic hypogonadism while increasing efficacy of treatment in resistant disorders such as PCOS. Difficulties experienced by patients in accepting the pump are often cited as a negative aspect of this form of therapy. However, in our experience, properly motivated patients rarely object to wearing the infusion pump; many women greatly enjoy the sense of well-being associated with having a physiological menstrual cycle restored and readily accept extended periods of treatments. Moreover, the inconvenience of wearing the pump and the delivery system is well

Vol. 56, No.1, July 1991

Filicori et al.

Ovulation induction with pulsatile GnRH

9

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compensated by the safety of treatment and the markedly reduced monitoring requirements, When the price of endocrine monitoring is factored in, the cost of pulsatile GnRH treatment (including pump use) is lower than that of hMG ovulation induction74,75; furthermore, the overall human and economic price of hMG complications, such as ovarian hyperstimulation and multiple pregnancy, should also be contemplated when assessing the cost/benefit ratio of ovulation induction methods, Because of these considerations, hMG currently should be reserved for primary pituitary disorders, for patients resistant to pulsatile GnRH, and, above all, for induction of multiple folliculogenesis in preparation for assisted reproduction techniques, whereas it would be desirable that pulsatile GnRH becomes the treatment of first choice, after CC failure, in the management of anovulatory infertility, SUMMARY

Over 10 years have passed since the introduction of pulsatile GnRH ovulation induction in clinical medicine, This technique has proven to be an effective and safe therapeutic tool in the management of 10

Filicori et al.

Ovulation induction with pulsatile GnRH

Figure 6 Daily gonadotropin and gonadal steroid levels during three cycles of pulsatile GnRH (51'g every 60 minutes) ovulation induction in a patient with secondary amenorrhea caused by hypogonadotropic hypogonadism, Notice in the first treatment cycle done without GnRH -a pretreatment (left panels) the brisk early endocrine response to GnRH stimulation with E2 levels > 2,000 pg/mL; hormone levels declined in spite of continued stimulation, and menses occurred after 34 days, This excessive response was abolished, and a normal endocrine pattern and ovulation ensued in the cycle done after analog pretreatment (middle panels), Pulsatile GnRH was continued for a second postanalog cycle (right panels); ovulation occurred, resulting in a singleton pregnancy, (From Filicori et aL 12 Reprinted with permission of the publisher),

anovulatory infertility, Absence of clinical ovarian hyperstimulation and the low incidence of multiple pregnancy are particularly advantageous for outpatient treatment, The recent introduction of special regimens such as GnRH-a suppression before pulsatile GnRH administration may further improve efficacy and reduce complications of this therapy, Acknowledgment We thank Ms. Silvia Arsento for outstanding secretarial assistance. This work was supported in part by grants from the National Research Council of Italy, ASTO Bologna, and the Regional Government of Emilia-Romagna. REFERENCES 1. Adashi EY: Clomiphene citrate: mechanism(s) and site(s) of

action-a hypothesis revisited. Fertil Steril 42:331, 1984 2. Oelsner G, Serr DM, Mashiach S, Blankstein J, Snyder M, Lunenfeld B: The study of induction of ovulation with menotropins: analysis of results of 1987 treatment cycles. Fertil Steril 30:538, 1978 3. Borenstein R, Elhalah U, Lunenfeld B, Schwartz ZS: Severe ovarian hyperstimulation syndrome: a reevaluated therapeutic approach. Fertil Steril 51:791, 1989 4. Amoss M, Burgus R, Blackwell R, Vale W, Fellows R, Guillemin R: Purification, amino acid composition and N-terminus of the hypothalamic luteinizing hormone-releasing factor (LRF) of ovine origin. Biochem Biophys Res Commun 44:205, 1971 Fertility and Sterility

5. Schally AV, Arimura A, Baba Y, Nair RM, Matsuo H, Redding TW, Debeljuk L: Isolation and properties of the FSH and LH-releasing hormone. Biochem Biophys Res Commun 43:393, 1971 6. Keller P: Treatment of anovulation with synthetic luteinizing hormone-releasing hormone. Am J Obstet Gynecol 116:698, 1973 7. Knobil E: The neuroendocrine control of the menstrual cycle. Recent Prog Horm Res 36:53, 1980 8. Hoffman AR, Crowley WF: Induction of puberty in men by long-term pulsatile administration of low-dose gonadotropinreleasing hormone. N Engl J Med 307:1237,1982 9. Crowley WF, McArthur JW: Simulation of the normal menstrual cycle in Kallman's syndrome by pulsatile administration of luteinizing hormone-releasing hormone (LHRH). J Clin Endocrinol Metab 51:173, 1980 10. Leyendecker G, Wildt L, Hansman M: Pregnancies following chronic intermittent (pulsatile) administration of Gn -RH by means of a portable pump ("Zyklomat"): a new approach to the treatment of infertility in hypothalamic amenorrhea. J Clin Endocrinol Metab 51:1214, 1980 11. Healy DL, Burger HG: Serum follicle-stimulating hormone, luteinizing hormone, and prolactin during the induction of ovulation with exogenous gonadotropin. J Clin Endocrinol Metab 56:474, 1983 12. Filicori M, Flamigni C, Meriggiola MC, Ferrari P, Michelacci L, Campaniello E, Valdiserri A, Cognigni G: Endocrine response determines the clinical outcome of pulsatile GnRH ovulation induction in different ovulatory disorders. J Clin Endocrinol Metab. In press, 1991 13. Meriggiola MC, Flamigni C, Valdiserri A, Ferrari P, Michelacci L, Campaniello E, Filicori M: Lack of discernible effects of a constantly rapid pulsatile GnRH frequency in the luteal phase (LP) upon gonadal function of subsequent menstrual cycles. (Abstr. 1354) Presented at the 72nd Annual Meeting of the Endocrine Society, Atlanta, Georgia, June 20 to 23, 1990. Published by the Endocrine Society, in the Program Supplement, 1990, p 363 14. Hurley DM, Brian R, Outch K, Stockdale J, Fry A, Hackman C, Clarke I, Burger HG: Induction of ovulation and fertility in amenorrheic women by pulsatile low-dose gonadotropinreleasing hormone. N Engl J Med 310:1069, 1984 15. Mattei A, Galparoli C, Spellecchia D, Crosignani PG: Induction of ovulation with pulsatile LHRH. Acta Eur Fertil 18:267, 1987 16. Skarin G, Nillius SJ, Wide L: Pulsatile low dose luteinizing hormone-releasing hormone treatment for induction of follicular maturation and ovulation in women with amenorrhea. Acta Endocrinol, (Copenh) 101:78, 1982 17. Blunt SM, Butt WR: Pulsatile GnRH therapy for the induction of ovulation in hypogonadotropic hypogonadism. Acta Endocrinol (Copenh) 288:58, 1988 18. Saffan D, Seibel MM: Ovulation induction with subcutaneous pulsatile gonadotropin-releasing hormone in various ovulatory disorders. Fertil SteriI45:475, 1986 19. Filicori M, Flamigni C, Campaniello E, Valdiserri A, Ferrari P, Meriggiola MC, Michelacci L, Pareschi A: The abnormal response of polycystic ovarian disease patients to exogenous pulsatile gonadotropin-releasing hormone: characterization and management. J Clin Endocrinol Metab 69:825, 1989 20. Geisthovel F, Peters F, Breckwoldt M: Ovarian hyperstimulation due to long-term pulsatile intravenous GnRH treatment. Arch Gynecol 236:255, 1985 Vol. 56, No.1, July 1991

21. Jansen RP, Handelsman DJ, Boylan LM, Conway A, Shearman RP, Fraser IS: Pulsatile intravenous gonadotropin-releasing hormone for ovulation-induction in infertile women. I. Safety and effectiveness with outpatient therapy. Fertil Steril 48:33, 1987 22. Schoemaker J, Simons AHM, van Osnabrugge GJC, Lugtenburg C, van Kessel H: Pregnancy after prolonged pulsatile administration of luteinizing hormone-releasing hormone in a patient with clomiphene-resistant secondary amenorrhea. J Clin Endocrinol Metab 52:882, 1981 23. Sutherland lA, White S, Chambers GR, Rothwell D, Mason PW, Tucker M, Jacobs HS: A miniature infuser for the pulsatile administration of LHRH. J Biomed Eng 6:129, 1984 24. Hanker JP, Bohnet HG, Schneider HPL: Nasal spray assisted pulsatile LH-RH in the treatment of hypothalamic amenorrhea. Neuroendocrinology Letters 2:269, 1980 25. Homburg R, Eshel A, Armar NA, Tucker M, Mason PW, Adams J, Kilborn J, Sutherland lA, Jacobs HS: One hundred pregnancies after treatment with pulsatile luteinising hormone-releasing hormone to induce ovulation. Br Med J 298: 809, 1989 26. Hopkins CC, Santoro NF, Hall JE, Martin KA, Wierman ME, Waldstreicher J, Filicori M, Crowley WF, Jr: Closed intravenous administration of gonadotropin-releasing hormone (GnRH): safety of long duration of peripheral intravenous catheterization. Obstet Gynecol 74:267, 1989 27. Burger CW, Korsen TJM, Hompes PGA, van Kessel H, Schoemaker J: Ovulation induction with pulsatile luteinizing releasing hormone in women with clomiphene citrate-resistant polycystic ovary-like disease: clinical results. Fertil Steril 46:1045, 1986 28. Ross LD, Robertson G, Milton PJ, Blows R: The induction of ovulation using pulsatile luteinizing hormone-releasing hormone in clinical practice. Br J Obstet Gynaecol 92:815, 1985 29. Soules MR, Southworth MB, Norton ME, Bremner WJ: Ovulation induction with pulsatile gonadotropin-releasing hormone: a study of the subcutaneous route of administration. Fertil Steril 46:578, 1986 30. Spratt DI, Crowley WF, Jr, Butler JP, Hoffman AR, Conn PM, Badger TM: Pituitary luteinizing hormone responses to intravenous and subcutaneous administration of gonadotropin-releasing hormone in men. J Clin Endocrinol Metab 61: 890, 1985 31. Couzinet B, Lahlou N, Lestrat N, Bouchard P, Roger M, Schaison G: Pulsatile luteinizing hormone-releasing hormone treatment for induction of ovulation. Radioimmunoassay of plasma LHRH and comparative study of subcutaneous versus intravenous routes of administration. J Endocrinol Invest 9: 103, 1986 32. Handelsman DJ, Swerdloff RS: Pharmacokinetics of gonadotropin-releasing hormone and its analogs. Endocr Rev 7:95, 1986 33. Loucopoulos A, Ferin M, Vande Wiele RL, Dyrenfurth I, Linkie D, Yeh M, Jewelewicz R: Pulsatile administration of gonadotropin-releasing hormone for induction of ovulation. Am J Obstet Gynecol 148:895, 1984 34. Riolo A, Carioni E, Lerro S, Albano M, Crippa A, Gelli D, Bini M, Pisoni P: Induction of ovulation with pulsatile GnRH: comparison between subcutaneous and intravenous administration in the same patients. Acta Eur Fertil 18:271, 1987 35. Leyendecker G, Struve T, Plotz EJ: Induction of ovulation with chronic intermittent (pulsatile) administration of LH-

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partial gonadotroph desensitization. J Clin Endocrinol Metab 66:165, 1988 Kazer RR, Kessel B, Yen SSC: Circulating luteinizing hormone pulse frequency in women with polycystic ovary syndrome. J Clin Endocrinol Metab 65:233, 1987 Adams J, Franks S, Polson DW, Mason HD, Abdulwahid N, Tucker M, Morris DV, Price J, Jacobs HS: Multifollicular ovaries: clinical and endocrine features and response to pulsatile gonadotropin-releasing hormone. Lancet 2:1375, 1985 Eshel A, Abdulwahid NA, Armar NA, Adams JM, Jacobs HS: Pulsatile luteinizing hormone-releasing hormone therapy in women with polycystic ovary syndrome. Fertil Steril 49: 956, 1988 Filicori M, Campaniello E, Michelacci L, Pareschi A, Ferrari P, Bolelli G, Flamigni C: Gonadotropin-releasing hormone (GnRH) analog suppression renders polycystic ovarian disease patients more susceptible to ovulation induction with pulsatile GnRH. J Clin Endocrinol Metab 66:327, 1988 Heineman MJ, Bouckaert PXJM, Schellekens LA: A quadruplet pregnancy following ovulation induction with pulsatile luteinizing hormone-releasing hormone. Fertil Steril 42:300, 1984

70. Bogchelman D, Lappon RE, Janssens J: Triplet pregnancy after pulsatile administration of gonadotropin -releasing hormone. Lancet 2:45, 1982 71. Aso T, Goto K, Takeuchi J, Kotsuji F, Tominaga T: A triplet pregnancy after gonadotropin-releasing hormone pulsatile infusion in a postoperative case of growth hormone-producing pituitary macroadenoma. Endocrinol Jpn 34:395, 1987 72. Filicori M, Michelacci L, Ferrari P, Campaniello E, Pareschi A, Flamigni C: Triplet pregnancy after low-dose pulsatile gonadotropin-releasing hormone in polycystic ovarian disease. Am J Obstet Gynecol 155:768, 1986 73. Homburg R, Armar NA, Eshel A, Adams J, Jacobs HS: Influence of serum luteinising hormone concentrations on ovulation, conception and early pregnancy loss in polycystic ovary syndrome. Br Med J 297:1024, 1988 74. Sueldo CE, Swanson JA: The economics of inducing ovulation with human menopausal gonadotropins versus pulsatile subcutaneous gonadotropin-releasing hormone. Fertil Steril45: 128, 1986 75. Martin K, Santoro N, Hall J, Filicori M, Wierman M, Crowley WF: Management of ovulatory disorders with pulsatile gonadotropin-releasing hormone. J Clin Endocrinol Metab 71: 1081A,1990

Received February 21, 1991. Reprint requests: Marco Filicori, M.D., Clinica Ostetrica e Ginecologica, Via Massarenti 13, 40138 Bologna, Italy.

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