- Email: [email protected]
Pregnancy outcomes after gastric-bypass surgery
The American Journal of Surgery 192 (2006) 762–766
Papers presented
Pregnancy outcomes after gastric-bypass surgery Tuoc Dao, M.D., Joseph Kuhn, M.D., Dale Ehmer, M.D., Tammy Fisher, R.N., Todd McCarty, M.D.* Baylor University Medical Center, 3409 Worth Street, Suite 420, Dallas, TX 75246, USA Manuscript received April 15, 2006; revised manuscript August 10, 2006 Presented at the 58th Annual Meeting of the Southwestern Surgical Congress, Kauai, Hawaii, April 3–7, 2006
Abstract Background: The purpose of this study is to compare outcomes of patients who become pregnant within the first year after surgery and those who delayed pregnancy until after 1 year after surgery. Methods: A retrospective review was performed to identify patients who became pregnant after their gastric-bypass surgery from 2001 to 2004. Endpoints included pregnancy complications, fetal birth weight and outcome, delivery method, weight change during pregnancy, and nutrition. Results: Of 2,423 patients who had undergone bariatric surgery from 2001 to 2004, 21 patients became pregnant within the first year after surgery and 13 became pregnant after 1 year. Similar outcomes were seen between the 2 groups regarding fetal weight, term pregnancy, and complications. Conclusions: Pregnancy outcomes within the first year after weight-loss surgery revealed no significant episodes of malnutrition, adverse fetal outcomes, or pregnancy complications. Anxiety over poor outcomes of pregnancy during the first year after bariatric surgery can be allayed. © 2006 Excerpta Medica Inc. All rights reserved. Keywords: Pregnancy; Gastric-bypass surgery
Obesity defined as a body mass index (BMI) ⬎30 kg/m2 is a growing problem in the United States and also worldwide. It is becoming the leading cause of preventable morbidity and mortality. Because the incidence of obesity is increasing, it is currently the second leading cause of death [1]. Because conservative management with diet and exercise has failed to obtain lasting results for some patients, more invasive treatments have become valuable options. Bariatric surgery has been proven effective for treating obesity [2– 4]. About 25% of women are affected by obesity, and one third of these women are of reproductive age [2]. Many of them are also seeking surgical treatment for obesity. Obese women who become pregnant have an increased incidence of complications including gestational diabetes mellitus, gestational hypertension, preeclampsia, fetal macrosomia, cesarean deliveries, and anesthesia-related complications compared with women with normal BMI (18 –25 kg/m2) [5–9]. With bariatric surgery and subsequent weight loss, these morbidities related to obesity would appear to be
reduced or eliminated [10]. However, limited data are available examining outcomes of pregnancy after gastric bypass [9,11–18]. The majority of recent studies have supported that pregnancy after gastric-bypass surgery is safe [14,16], but recommendations have advised women to delay pregnancy for 12 to 18 months after bariatric surgery [11,13]. During the first year after surgery, patients undergo a rapid weight loss phase, and there is the concern that the patient or baby may become unhealthy in this relative starvation state [13]. There is a potential for developing iron, vitamin B12, folate, and calcium deficiencies after malabsorptive surgery [11]. We hypothesize that pregnancy within the first year with proper nutrition and monitoring will have similar outcomes to those patients who delay pregnancy after 1 year. In our retrospective review, we examine the outcomes of pregnancy after gastric-bypass surgery in patients who become pregnant within the first year (early group) and those who delayed the onset of pregnancy after 1 year of their surgery (late group).
* Corresponding author. Tel.: ⫹1-214-824-9963; fax: ⫹1-214-8247167. E-mail address: [email protected]
Methods and Materials A retrospective review was performed to identify patients who became pregnant after their gastric-bypass sur-
0002-9610/06/$ – see front matter © 2006 Excerpta Medica Inc. All rights reserved. doi:10.1016/j.amjsurg.2006.08.041
T. Dao et al. / The American Journal of Surgery 192 (2006) 762–766
gery from 2001 to 2004 at a single institution. This information is maintained in a database that includes all patients that have undergone gastric-bypass surgery from 2001 to present and is regularly maintained through clinical records, surveys, and telephone interviews. Informed consent was obtained from each of the patients, and approval was obtained from the institutional review board. These patients underwent Roux-en-Y gastric bypass with a 15- to 30-mL pouch. Patients are routinely advised to delay pregnancy until 1 year after surgery. After identifying the women who became pregnant after gastric-bypass surgery, additional information was obtained about their pregnancy, birth, and outcomes through office charts, hospital records, and telephone interviews. These women were separated into 2 groups: those who became pregnant within the first postoperative year (early group) and those who delayed pregnancy after the first year (late group). The following clinical data were examined: complications during pregnancy, fetal birth weight, fetal outcome, method of delivery, weight change during and after pregnancy, and nutritional outcome. Results Of 2432 patients undergoing weight-loss surgery from 2001 to 2004, 34 patients reported becoming pregnant after surgery. Thirty-three patients underwent laparoscopic Rouxen-Y gastric bypass, whereas 1 patient had an open procedure. Twenty-one patients became pregnant within the first postoperative year (early group), whereas 13 patients delayed pregnancy until after 1 year (late group). The early and late groups were similar in age and BMI (Table 1). During the pregnancy, all patients maintained adequate nutritional intake based on albumin levels, B12, thiamine, and calcium monitoring. Of the 21 pregnancies in the early group, there were 5 miscarriages, 1 ectopic pregnancy, and 1 set of twins. Of the remaining pregnancies, all were carried to term except for the set of twins. The set of twins were carried to 35 weeks gestation and had low birth weight (2325 g, 1786 g). All of the babies carried to term were born healthy, and no congenital defects were observed. The average birth weight was 2868 g, with a range of 1786 to 3940 g. Nine babies were delivered vaginally, whereas 6 were delivered by cesarean section. Three of the cesarean deliveries were repeat cesarean sections. Before gastric-bypass surgery, 8 patients reported problems with infertility. Patients in the early group had an average weight gain of 4 lb. There was a wide range of change in weight with some patients losing up to 70 lb during their pregnancy and with others gaining weight up to 45 lb. After their pregnancies, most of the patients were able to lose further weight (average 14 lb) except for 1 patient who gained 31 lb. Complications during pregnancy were minimal with 1 patient having symptomatic cholelithiasis requiring hospitalization. She subsequently had a laparoscopic cholecystectomy after delivering her baby. Other complications included bed rest (n ⫽ 1), preterm labor (n ⫽ 1), and slight hypertension (n ⫽ 1). One patient had mild iron deficiency that corrected with supplements. In the late group, 13 patients delayed pregnancy after 1
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Table 1 Characteristics of early and late group pregnancies
Mean age Mean body mass index At surgery At pregnancy‡ Preterm births Average weight gain during pregnancy‡ Type of delivery Vaginal Cesarean Pregnancy complications Major* Minor† Delivery complications Fetal complications
Early group (n ⫽ 21)
Late group (n ⫽ 13)
P value
32
34
.147
49 35 1 set of twins 4 lb
46 28 2 sets of twins 34 lb
.192 .0024‡
9 (60.0%) 6 (40.0%)
6 (46.2%) 7 (58.8%)
.002‡ .464
5 (23.8%) 5 (25%) 0
1 (7.7%) 3 (21%) 1 placental abruption 1 ectopic pregnancy 0
.132* 1.000†
Patients in the early group had a significantly higher BMI at pregnancy than patients in the late group. Age, BMI and average weight gain during pregnancy comparison in the 2 groups performed by t test. P values of .05 or less were considered statistically significant. No significant difference in BMI at surgery, age, type of delivery, and pregnancy complications. * Major includes preeclampsia and miscarriages. † Minor includes preterm labor, hypertension, cholelithiasis, and iron deficiency. ‡ Results showed average weight gain during pregnancy to be statistically significantly less in the early group than in the late group (4 lb versus 34 lb, P ⫽ .002).
year of gastric-bypass surgery. There were 3 sets of twins with 2 sets of twins born preterm. Both preterm sets of twins had low birth weight (1616-1899 g). All other pregnancies were carried to term. The average birth weight was 2727 g with a range of 1616 to 3895 g. Seven patients had cesarean section with 1 patient having repeat cesarean section delivery. The other 6 patients underwent vaginal delivery. All of these babies were also born healthy and without congenital defects. Four patients had reported difficulty becoming pregnant before their weight-loss surgery. Within the late group, the average weight gain was 34 lb with a range of 13 to 75 lb. After their pregnancy, most of the patients were able to lose weight gained during the pregnancy (average 21 lb). Complications during pregnancy in the late group included placental abruption (n ⫽ 1), preterm labor (n ⫽ 2), preeclampsia (n ⫽ 1), and bed rest (n ⫽ 1). No nutritional deficiencies were noted in the late group. A statistical comparison found no difference in the incidence of preterm labor, preeclampsia, fetal birth weight, or rate of cesarean section (Table 1). Comments The course of pregnancy within the first year after weight-loss surgery was not significantly different compared with those who became pregnant beyond the first year. Although the early group gained less weight during pregnancy, there were no statistically significant differences in regards to fetal birth weight, term pregnancy, and complications (Table 1). Prior early reports of pregnancy com-
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plications after weight-loss surgery and jejunal intestinal bypass included gastrointestinal bleeding [19], anemia [14], intrauterine growth retardation [20], and neural tube defects [21,22]. From these early experiences and case reports, the metabolic changes and potential effects of weight-loss surgery on pregnancy warrant close surveillance of fetal growth and screening for nutritional deficiencies. Women who become pregnant after bariatric surgery are advised to continue with vitamin supplementation including vitamin B12, iron, and folate. Recent studies with pregnancy after Roux-en-Y gastric bypass have shown no adverse perinatal outcomes [9,23]. Sheiner et al [9] reviewed 298 pregnancies after restrictive and malabsorptive bariatric surgery and found no difference in pregnancy or perinatal complications compared with women in the general population. They also observed a higher incidence of fetal macrosomia (birth weight ⬎4 kg) associated with pregnancy after bariatric surgery, but that was not observed in this study. Pregnancy after gastric-bypass surgery has been found to be well tolerated with minimal metabolic complications including low incidence of B12 and iron deficiencies [15,17]. There has been 1 case report of an infant developing B12 deficiency after being exclusively breastfed from a mother with asymptomatic B12 deficiency [24]. In another case report, 1 mother developed vitamin B12 deficiency that was refractory to oral supplementation and ultimately required blood transfusions to correct her anemia [14]. However, few studies have addressed pregnancies conceived within the first year of weight-loss surgery. Printen and Scott [15] found that pregnancy within the period of rapid weight loss did not adversely affect the mother or developing fetus. Pregnancy in obese patients can carry a higher incidence of complications involving increased risk of gestational diabetes, gestational hypertension, preeclampsia, fetal anomalies, fetal macrosomia, preterm labor, and increased cesarean delivery [2]. In another study, Cedegren [25] reported a 3-fold higher incidence of antepartum stillbirth in morbidly obese women compared with control women. Recent studies also suggest that obesity in pregnancy is associated with an increased risk of neural tube defects, especially spina bifida [26,27]. Werler et al [27] examined neural tube defects in obese women along with their daily folate intake and concluded that women with an absolute body weight greater than 70 kg were not protected against neural tube defects with the recommended daily intake of folate. They also found that the risk of neural tube defects increases with maternal weight regardless of folic acid intake. The mechanism of this resistance is still unknown, but several theories include potentially lower levels of folate are reaching the fetus because of poor absorption and higher metabolic demands [2]. With the higher incidence of complications associated with maternal obesity, the benefits of gastric-bypass surgery and weight loss on pregnancy are still yet to be determined. Many of the women in the early group had irregular menstrual periods or were anovulatory before their weightloss surgery. Therefore, many did not expect to become pregnant so soon after surgery. After losing a significant amount of weight, menstrual cycles can normalize and infertility problems can resolve [28]. This normalization of menstrual cycles can lead to “surprise” pregnancies within
the first year after gastric-bypass surgery. If patients are not ready for children after weight-loss surgery, they should be advised to consider contraception during their first year to prevent “surprise” pregnancies. Patients who become pregnant after weight-loss surgery are followed more frequently than the general population with serial ultrasounds every 4 to 6 weeks starting at 24 weeks gestation to monitor fetal growth. Patients in the early and late group were managed similarly during their pregnancy by monitoring maternal nutrition and fetal development. The patients in the early group did have a higher incidence of miscarriage (24%) than the late group (0%). This is slightly higher than the normal range compared with the 15% to 20% incidence within the general population. Although this was not statistically significant because of the small number of subjects, patients may still need to be cautioned about the potential for miscarriage within the first postoperative year. A larger study would be needed to examine the risk of miscarriage in the early group compared with those in the late group. Low statistical power exists in general for most of the outcomes evaluated. This suggests that the study was underpowered, and it may not be able to detect statistical group differences for some outcomes when differences actually exist. Recommendations have maintained that women should delay pregnancy 12 to 18 months to avoid detrimental effects during the rapid weight-loss phase [11,13,29]. This would prevent the potential risk of the mother or baby from becoming unhealthy during this phase [13]. During this time, only small meals are being consumed while incurring significant weight loss. At our institution, we also recommend that women delay pregnancy 1 year after bariatric surgery. In our review, the potential adverse outcomes on the fetus or mother during the first year after weight-loss surgery were not seen. No significant episodes of malnutrition, adverse fetal outcomes, or intrauterine growth retardation were seen in either group. Most of the complications were minimal in each group. Major complications in the early group were limited to 1 ectopic pregnancy. In the late group, 1 patient had placental abruption complicated by disseminated intravascular coagulation, but a healthy baby was delivered by emergency cesarean section. Both the mother and baby did well. In our study, patients had similar overall weight loss after their pregnancies in both the early group (99 lb) and the late group (113 lb). Thus, patients in the early group were still able to lose weight despite becoming pregnant within 1 year of their gastric-bypass surgery. Because more people are choosing gastric-bypass surgery to treat their morbid obesity, we will be seeing more women of childbearing age. With nutritional supplements and careful monitoring of the fetus and mother, early detection of problems with the pregnancy can be identified and corrected. Although patients are advised to delay pregnancy 12 to 18 months after weight-loss surgery, the results of this study have shown minimal complications related to nutrition, fetal development, and pregnancy. This continues to support that pregnancy after weight-loss surgery is safe with proper monitoring and counseling. Although we still support that delaying pregnancy after the first year as a safe option, we propose that patient and physician anxiety over poor outcomes of pregnancy during the first year can be allayed.
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References [1] Allison DB, Fonatine DR, Manson JE, et al. Annual deaths attributable to obesity in the United States. JAMA 1999;282:1530 – 8. [2] Hall L, Neubert G. Obesity and pregnancy. Obstet Gynecol Surv 2005;60:253– 60. [3] Clegg A, Colquitt J, Sidhu M, Royle P, et al. Clinical and cost effectiveness of surgery for morbid obesity: a systematic review and economic evaluation. Int J Obes Relat Metab Disord 2003;27: 1167–77. [4] Wittgrove AC, Clark GW, Schubert KR. Laparoscopic gastric bypass, Roux en-Y: techniques and results in 75 patients with 3–30 months follow-up. Obes Surg 1996;6:500 – 4. [5] Kumari AS. Pregnancy outcome in women with morbid obesity. Int J Gynaecol Obstet 2001;73:101–7. [6] Cnattingius S, Bergstrom R, Liworth L, Kramer MS. Prepregnancy weight and the risk of adverse pregnancy outcomes. N Engl J Med 1998;338:147–52. [7] Ratner RE, Hamner LH, Isada NG. Effects of gestational weight gain in morbidly obese women: fetal morbidity. Am J Perinatol 1990;7: 295–9. [8] Isaacs JD, Magnon EF, Martin RW, et al. Obstetric challenges of massive obesity complicating pregnancy. J Perinatol 1994;14:10 – 4. [9] Sheiner E, Levy A, Silverberg D, et al. Pregnancy after bariatric surgery is not associated with adverse perinatal outcome. Am J Obstet Gynecol 2004;190:1335– 40. [10] Raymond R. Hormonal status, fertility, and pregnancy before and after bariatric surgery. Crit Care Nurs Q 2005;28:263– 8. [11] Martin LF, Finigan K, Nolan T. Pregnancy after adjustable gastric banding. Obstet Gynecol 2000;95:927–30. [12] Woodard C. Pregnancy following bariatric surgery. J Perinat Neonatal Nurs 2004;18:329 – 40. [13] Wittgrove AC, Jester L, Wittgrove P, Clark GW. Pregnancy following gastric bypass for morbid obesity. Obes Surg 1998;8:461– 6. [14] Gurewitsch ED, Smith-Levitin M, Mack J. Pregnancy following gastric bypass surgery for morbid obesity. Obstet Gynecol 1996;88:658 – 61. [15] Printen KJ, Scott D. Pregnancy following gastric bypass for the treatment of morbid obesity. Am Surg 1982;48:363–5. [16] Richards DS, Miller DK, Goodman GN. Pregnancy after gastric bypass for morbid obesity. J Reprod Med 1987;32:172– 6. [17] Rand CS, Macgregor AM. Medical care and pregnancy outcome after gastric bypass surgery for obesity. South Med J 1989;82:1319 –20. [18] Dixon JB, Dixon ME, O’Brien PE. Pregnancy after lap-band surgery: management of the band to achieve healthy weight outcomes. Obes Surg 2001;11:59 – 65. [19] Ramirez MM, Turrentine MA. Gastrointestinal hemorrhage during pregnancy in a patient with history of vertical-banded gastroplasty. Am J Obstet Gynecol 2001;173:1630 –1. [20] Granstrom L, Granstrom L, Backman L. Fetal growth retardation after gastric banding. Acta Obstet Gynecol Scand 1990;69:533– 6. [21] Haddow JE, Hill LE, Kloza EM, Thanhauser D. Neural tube defects after gastric bypass. Lancet 1986;1:1330. [22] Martin L, Chavez GF, Adams MJ Jr, et al. Gastric bypass surgery as maternal risk factor for neural tube defects. Lancet 1988;1:640 –1. [23] Marceau P, Kaufman D, Biron S, et al. Outcome of pregnancies after biliopancreatic diversion. Obes Surg 2004;14:318 –24. [24] Grange DK, Finlay JL. Nutritional vitamin B12 deficiency in a breastfed infant following maternal gastric bypass. Pediatr Hematol Oncol 1994;11:311– 8. [25] Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol 2004;103:219 –24. [26] Waller DK, Mills JL, Simpson JP, et al. Are obese women at higher risk for producing malformed offspring? Am J Obstet Gynecol 1994; 170:541– 8. [27] Werler MM, Louik C, Shapiro S, et al. Prepregnant weight in relation to risk of neural tube defects. JAMA 1996;275:1089 –92. [28] Deitel M, Stone E, Kassam HA, et al. Gynecologic-obstetric changes after loss of massive excess weight following bariatric surgery. J Am Coll Nutr 1998;7:147–53. [29] Kakarla N, Dailey C, Marino T, et al. Pregnancy after gastric bypass surgery and internal hernia formation. Obstet Gynecol 2005;105: 1195– 8.
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Discussion Corrigan McBride, M.D. (Omaha, NE): The number of bariatric surgical procedures in this country is growing every year. ASBS estimates there will be over 200,000 gastric bypasses performed in 2006; 80% to 90% of the patients who are considering surgery tend to be female, and the mean age in most large studies ranges from about 38 years to 42 years so they are certainly in their reproductive ages. The authors today presented a retrospective study of 2,432 bariatric surgery patients. They do maintain a database that they update regularly with clinic records, telephone calls, and surveys according to the manuscript. And all of these data are prospectively collected. They were able to identify 34 patients who had pregnancy after bariatric surgery, and they divided these patients into 2 groups. An early group became pregnant in the first year and a late group who delayed their pregnancy until after 1 year. Because of the increasing information that is available to the patients on the Internet in the lay press, most of us now get these questions very commonly from our prospective patients, so I think this is a very important topic to touch on. But I do have several questions: first, you did not provide any data on whether or not these were first pregnancies or whether they were third, fourth, or fifth pregnancies. It would be interesting to know how post– bariatric surgery pregnancies compared with pre– bariatric surgery pregnancies. Second, compliance is a major problem in the bariatric surgical population. If you recommend that they wait 1 year, but they get pregnant anyway in that first year, does this indicate that they will be noncompliant with your other recommendations, such as vitamins, diet, exercise, and follow-up? In other words, how many pregnant patients are there that you do not know about because you have lost these people to follow-up? And finally, because the patients’ primary motivator for surgery has been weight loss and improve their health, what impact did these pregnancies have on their final excess body weight loss, BMI, and the resolution of their preoperative comorbidities? Kai Nishi, M.D. (Los Angeles, CA): The literature suggests that prenatal vitamins be given on top of the standard regimen of B12 and multivitamins given to postbypass patients. Do you recommend this? Tuoc Dao, M.D. (Dallas, TX): In regards to your first question about the number of pregnancies these patients had, I did review that data in these women. For the majority of the patients, this was their first pregnancy. Many of these women had infertility problems related to their obesity, and they had difficulties becoming pregnant before their weight loss. Some women during their interview also stated that infertility problems were one of the reasons they pursued weight-loss surgery. After significant weight loss, their menstrual cycles can regulate and increase their fertility and ability to conceive. There were 5 patients in the study that had prior pregnancies. When comparing prebariatric pregnancies to postbariatric pregnancies, these women after their gastric-bypass
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surgery did have a decreased incidence of preeclampsia, pregnancy induced hypertension, and gestational diabetes. Patients had less complications related to their pregnancy after their weight loss. As far as noncompliance, that is always an issue with our patients. The only thing we can do is provide good information and counseling to our patients about bariatric surgery and the importance of compliance to ensure successful weight loss long term. At our institution, we have a program in place for long-term follow-up with our patients. We have outpatient appointments at regular intervals. We also continue to send out letters, surveys, and make telephone calls to maintain contact with our patients. Because a number of patients will inevitably be lost to follow-up, it is important that others in the medical community be aware of these issues as well. It is difficult to know the exact number of patients that have become pregnant after their gastric bypass, but it is most likely an underestimated number. Because more patients are undergoing Roux-en Y gastric-
bypass surgery, these issues will become more common and prevalent. Overall, the pregnancies did not negatively affect the patients’ ability to lose weight in both groups of patients. On average, their final weight loss from the initial time of surgery was 99 lb for the early group and 113 lb for the late group. The final BMI was also similar in both the early and late groups (33 versus 30). They were still able to experience the same benefits as other nonpregnant gastric-bypass patients. For a majority of the women, their comorbidities, including hypertension and diabetes, did resolve after significant weight loss. There were a small percentage of patients, 5% to 10%, which failed surgical treatment. They were unable to maintain their weight loss long term. Dr Nishi, it is recommended that patients take prenatal vitamins in addition to their standard supplements of B12 and multivitamins after they become pregnant. These prenatal vitamins include folate, which is important for fetal growth and prevention of birth defects.
Papers presented
Pregnancy outcomes after gastric-bypass surgery Tuoc Dao, M.D., Joseph Kuhn, M.D., Dale Ehmer, M.D., Tammy Fisher, R.N., Todd McCarty, M.D.* Baylor University Medical Center, 3409 Worth Street, Suite 420, Dallas, TX 75246, USA Manuscript received April 15, 2006; revised manuscript August 10, 2006 Presented at the 58th Annual Meeting of the Southwestern Surgical Congress, Kauai, Hawaii, April 3–7, 2006
Abstract Background: The purpose of this study is to compare outcomes of patients who become pregnant within the first year after surgery and those who delayed pregnancy until after 1 year after surgery. Methods: A retrospective review was performed to identify patients who became pregnant after their gastric-bypass surgery from 2001 to 2004. Endpoints included pregnancy complications, fetal birth weight and outcome, delivery method, weight change during pregnancy, and nutrition. Results: Of 2,423 patients who had undergone bariatric surgery from 2001 to 2004, 21 patients became pregnant within the first year after surgery and 13 became pregnant after 1 year. Similar outcomes were seen between the 2 groups regarding fetal weight, term pregnancy, and complications. Conclusions: Pregnancy outcomes within the first year after weight-loss surgery revealed no significant episodes of malnutrition, adverse fetal outcomes, or pregnancy complications. Anxiety over poor outcomes of pregnancy during the first year after bariatric surgery can be allayed. © 2006 Excerpta Medica Inc. All rights reserved. Keywords: Pregnancy; Gastric-bypass surgery
Obesity defined as a body mass index (BMI) ⬎30 kg/m2 is a growing problem in the United States and also worldwide. It is becoming the leading cause of preventable morbidity and mortality. Because the incidence of obesity is increasing, it is currently the second leading cause of death [1]. Because conservative management with diet and exercise has failed to obtain lasting results for some patients, more invasive treatments have become valuable options. Bariatric surgery has been proven effective for treating obesity [2– 4]. About 25% of women are affected by obesity, and one third of these women are of reproductive age [2]. Many of them are also seeking surgical treatment for obesity. Obese women who become pregnant have an increased incidence of complications including gestational diabetes mellitus, gestational hypertension, preeclampsia, fetal macrosomia, cesarean deliveries, and anesthesia-related complications compared with women with normal BMI (18 –25 kg/m2) [5–9]. With bariatric surgery and subsequent weight loss, these morbidities related to obesity would appear to be
reduced or eliminated [10]. However, limited data are available examining outcomes of pregnancy after gastric bypass [9,11–18]. The majority of recent studies have supported that pregnancy after gastric-bypass surgery is safe [14,16], but recommendations have advised women to delay pregnancy for 12 to 18 months after bariatric surgery [11,13]. During the first year after surgery, patients undergo a rapid weight loss phase, and there is the concern that the patient or baby may become unhealthy in this relative starvation state [13]. There is a potential for developing iron, vitamin B12, folate, and calcium deficiencies after malabsorptive surgery [11]. We hypothesize that pregnancy within the first year with proper nutrition and monitoring will have similar outcomes to those patients who delay pregnancy after 1 year. In our retrospective review, we examine the outcomes of pregnancy after gastric-bypass surgery in patients who become pregnant within the first year (early group) and those who delayed the onset of pregnancy after 1 year of their surgery (late group).
* Corresponding author. Tel.: ⫹1-214-824-9963; fax: ⫹1-214-8247167. E-mail address: [email protected]
Methods and Materials A retrospective review was performed to identify patients who became pregnant after their gastric-bypass sur-
0002-9610/06/$ – see front matter © 2006 Excerpta Medica Inc. All rights reserved. doi:10.1016/j.amjsurg.2006.08.041
T. Dao et al. / The American Journal of Surgery 192 (2006) 762–766
gery from 2001 to 2004 at a single institution. This information is maintained in a database that includes all patients that have undergone gastric-bypass surgery from 2001 to present and is regularly maintained through clinical records, surveys, and telephone interviews. Informed consent was obtained from each of the patients, and approval was obtained from the institutional review board. These patients underwent Roux-en-Y gastric bypass with a 15- to 30-mL pouch. Patients are routinely advised to delay pregnancy until 1 year after surgery. After identifying the women who became pregnant after gastric-bypass surgery, additional information was obtained about their pregnancy, birth, and outcomes through office charts, hospital records, and telephone interviews. These women were separated into 2 groups: those who became pregnant within the first postoperative year (early group) and those who delayed pregnancy after the first year (late group). The following clinical data were examined: complications during pregnancy, fetal birth weight, fetal outcome, method of delivery, weight change during and after pregnancy, and nutritional outcome. Results Of 2432 patients undergoing weight-loss surgery from 2001 to 2004, 34 patients reported becoming pregnant after surgery. Thirty-three patients underwent laparoscopic Rouxen-Y gastric bypass, whereas 1 patient had an open procedure. Twenty-one patients became pregnant within the first postoperative year (early group), whereas 13 patients delayed pregnancy until after 1 year (late group). The early and late groups were similar in age and BMI (Table 1). During the pregnancy, all patients maintained adequate nutritional intake based on albumin levels, B12, thiamine, and calcium monitoring. Of the 21 pregnancies in the early group, there were 5 miscarriages, 1 ectopic pregnancy, and 1 set of twins. Of the remaining pregnancies, all were carried to term except for the set of twins. The set of twins were carried to 35 weeks gestation and had low birth weight (2325 g, 1786 g). All of the babies carried to term were born healthy, and no congenital defects were observed. The average birth weight was 2868 g, with a range of 1786 to 3940 g. Nine babies were delivered vaginally, whereas 6 were delivered by cesarean section. Three of the cesarean deliveries were repeat cesarean sections. Before gastric-bypass surgery, 8 patients reported problems with infertility. Patients in the early group had an average weight gain of 4 lb. There was a wide range of change in weight with some patients losing up to 70 lb during their pregnancy and with others gaining weight up to 45 lb. After their pregnancies, most of the patients were able to lose further weight (average 14 lb) except for 1 patient who gained 31 lb. Complications during pregnancy were minimal with 1 patient having symptomatic cholelithiasis requiring hospitalization. She subsequently had a laparoscopic cholecystectomy after delivering her baby. Other complications included bed rest (n ⫽ 1), preterm labor (n ⫽ 1), and slight hypertension (n ⫽ 1). One patient had mild iron deficiency that corrected with supplements. In the late group, 13 patients delayed pregnancy after 1
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Table 1 Characteristics of early and late group pregnancies
Mean age Mean body mass index At surgery At pregnancy‡ Preterm births Average weight gain during pregnancy‡ Type of delivery Vaginal Cesarean Pregnancy complications Major* Minor† Delivery complications Fetal complications
Early group (n ⫽ 21)
Late group (n ⫽ 13)
P value
32
34
.147
49 35 1 set of twins 4 lb
46 28 2 sets of twins 34 lb
.192 .0024‡
9 (60.0%) 6 (40.0%)
6 (46.2%) 7 (58.8%)
.002‡ .464
5 (23.8%) 5 (25%) 0
1 (7.7%) 3 (21%) 1 placental abruption 1 ectopic pregnancy 0
.132* 1.000†
Patients in the early group had a significantly higher BMI at pregnancy than patients in the late group. Age, BMI and average weight gain during pregnancy comparison in the 2 groups performed by t test. P values of .05 or less were considered statistically significant. No significant difference in BMI at surgery, age, type of delivery, and pregnancy complications. * Major includes preeclampsia and miscarriages. † Minor includes preterm labor, hypertension, cholelithiasis, and iron deficiency. ‡ Results showed average weight gain during pregnancy to be statistically significantly less in the early group than in the late group (4 lb versus 34 lb, P ⫽ .002).
year of gastric-bypass surgery. There were 3 sets of twins with 2 sets of twins born preterm. Both preterm sets of twins had low birth weight (1616-1899 g). All other pregnancies were carried to term. The average birth weight was 2727 g with a range of 1616 to 3895 g. Seven patients had cesarean section with 1 patient having repeat cesarean section delivery. The other 6 patients underwent vaginal delivery. All of these babies were also born healthy and without congenital defects. Four patients had reported difficulty becoming pregnant before their weight-loss surgery. Within the late group, the average weight gain was 34 lb with a range of 13 to 75 lb. After their pregnancy, most of the patients were able to lose weight gained during the pregnancy (average 21 lb). Complications during pregnancy in the late group included placental abruption (n ⫽ 1), preterm labor (n ⫽ 2), preeclampsia (n ⫽ 1), and bed rest (n ⫽ 1). No nutritional deficiencies were noted in the late group. A statistical comparison found no difference in the incidence of preterm labor, preeclampsia, fetal birth weight, or rate of cesarean section (Table 1). Comments The course of pregnancy within the first year after weight-loss surgery was not significantly different compared with those who became pregnant beyond the first year. Although the early group gained less weight during pregnancy, there were no statistically significant differences in regards to fetal birth weight, term pregnancy, and complications (Table 1). Prior early reports of pregnancy com-
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plications after weight-loss surgery and jejunal intestinal bypass included gastrointestinal bleeding [19], anemia [14], intrauterine growth retardation [20], and neural tube defects [21,22]. From these early experiences and case reports, the metabolic changes and potential effects of weight-loss surgery on pregnancy warrant close surveillance of fetal growth and screening for nutritional deficiencies. Women who become pregnant after bariatric surgery are advised to continue with vitamin supplementation including vitamin B12, iron, and folate. Recent studies with pregnancy after Roux-en-Y gastric bypass have shown no adverse perinatal outcomes [9,23]. Sheiner et al [9] reviewed 298 pregnancies after restrictive and malabsorptive bariatric surgery and found no difference in pregnancy or perinatal complications compared with women in the general population. They also observed a higher incidence of fetal macrosomia (birth weight ⬎4 kg) associated with pregnancy after bariatric surgery, but that was not observed in this study. Pregnancy after gastric-bypass surgery has been found to be well tolerated with minimal metabolic complications including low incidence of B12 and iron deficiencies [15,17]. There has been 1 case report of an infant developing B12 deficiency after being exclusively breastfed from a mother with asymptomatic B12 deficiency [24]. In another case report, 1 mother developed vitamin B12 deficiency that was refractory to oral supplementation and ultimately required blood transfusions to correct her anemia [14]. However, few studies have addressed pregnancies conceived within the first year of weight-loss surgery. Printen and Scott [15] found that pregnancy within the period of rapid weight loss did not adversely affect the mother or developing fetus. Pregnancy in obese patients can carry a higher incidence of complications involving increased risk of gestational diabetes, gestational hypertension, preeclampsia, fetal anomalies, fetal macrosomia, preterm labor, and increased cesarean delivery [2]. In another study, Cedegren [25] reported a 3-fold higher incidence of antepartum stillbirth in morbidly obese women compared with control women. Recent studies also suggest that obesity in pregnancy is associated with an increased risk of neural tube defects, especially spina bifida [26,27]. Werler et al [27] examined neural tube defects in obese women along with their daily folate intake and concluded that women with an absolute body weight greater than 70 kg were not protected against neural tube defects with the recommended daily intake of folate. They also found that the risk of neural tube defects increases with maternal weight regardless of folic acid intake. The mechanism of this resistance is still unknown, but several theories include potentially lower levels of folate are reaching the fetus because of poor absorption and higher metabolic demands [2]. With the higher incidence of complications associated with maternal obesity, the benefits of gastric-bypass surgery and weight loss on pregnancy are still yet to be determined. Many of the women in the early group had irregular menstrual periods or were anovulatory before their weightloss surgery. Therefore, many did not expect to become pregnant so soon after surgery. After losing a significant amount of weight, menstrual cycles can normalize and infertility problems can resolve [28]. This normalization of menstrual cycles can lead to “surprise” pregnancies within
the first year after gastric-bypass surgery. If patients are not ready for children after weight-loss surgery, they should be advised to consider contraception during their first year to prevent “surprise” pregnancies. Patients who become pregnant after weight-loss surgery are followed more frequently than the general population with serial ultrasounds every 4 to 6 weeks starting at 24 weeks gestation to monitor fetal growth. Patients in the early and late group were managed similarly during their pregnancy by monitoring maternal nutrition and fetal development. The patients in the early group did have a higher incidence of miscarriage (24%) than the late group (0%). This is slightly higher than the normal range compared with the 15% to 20% incidence within the general population. Although this was not statistically significant because of the small number of subjects, patients may still need to be cautioned about the potential for miscarriage within the first postoperative year. A larger study would be needed to examine the risk of miscarriage in the early group compared with those in the late group. Low statistical power exists in general for most of the outcomes evaluated. This suggests that the study was underpowered, and it may not be able to detect statistical group differences for some outcomes when differences actually exist. Recommendations have maintained that women should delay pregnancy 12 to 18 months to avoid detrimental effects during the rapid weight-loss phase [11,13,29]. This would prevent the potential risk of the mother or baby from becoming unhealthy during this phase [13]. During this time, only small meals are being consumed while incurring significant weight loss. At our institution, we also recommend that women delay pregnancy 1 year after bariatric surgery. In our review, the potential adverse outcomes on the fetus or mother during the first year after weight-loss surgery were not seen. No significant episodes of malnutrition, adverse fetal outcomes, or intrauterine growth retardation were seen in either group. Most of the complications were minimal in each group. Major complications in the early group were limited to 1 ectopic pregnancy. In the late group, 1 patient had placental abruption complicated by disseminated intravascular coagulation, but a healthy baby was delivered by emergency cesarean section. Both the mother and baby did well. In our study, patients had similar overall weight loss after their pregnancies in both the early group (99 lb) and the late group (113 lb). Thus, patients in the early group were still able to lose weight despite becoming pregnant within 1 year of their gastric-bypass surgery. Because more people are choosing gastric-bypass surgery to treat their morbid obesity, we will be seeing more women of childbearing age. With nutritional supplements and careful monitoring of the fetus and mother, early detection of problems with the pregnancy can be identified and corrected. Although patients are advised to delay pregnancy 12 to 18 months after weight-loss surgery, the results of this study have shown minimal complications related to nutrition, fetal development, and pregnancy. This continues to support that pregnancy after weight-loss surgery is safe with proper monitoring and counseling. Although we still support that delaying pregnancy after the first year as a safe option, we propose that patient and physician anxiety over poor outcomes of pregnancy during the first year can be allayed.
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References [1] Allison DB, Fonatine DR, Manson JE, et al. Annual deaths attributable to obesity in the United States. JAMA 1999;282:1530 – 8. [2] Hall L, Neubert G. Obesity and pregnancy. Obstet Gynecol Surv 2005;60:253– 60. [3] Clegg A, Colquitt J, Sidhu M, Royle P, et al. Clinical and cost effectiveness of surgery for morbid obesity: a systematic review and economic evaluation. Int J Obes Relat Metab Disord 2003;27: 1167–77. [4] Wittgrove AC, Clark GW, Schubert KR. Laparoscopic gastric bypass, Roux en-Y: techniques and results in 75 patients with 3–30 months follow-up. Obes Surg 1996;6:500 – 4. [5] Kumari AS. Pregnancy outcome in women with morbid obesity. Int J Gynaecol Obstet 2001;73:101–7. [6] Cnattingius S, Bergstrom R, Liworth L, Kramer MS. Prepregnancy weight and the risk of adverse pregnancy outcomes. N Engl J Med 1998;338:147–52. [7] Ratner RE, Hamner LH, Isada NG. Effects of gestational weight gain in morbidly obese women: fetal morbidity. Am J Perinatol 1990;7: 295–9. [8] Isaacs JD, Magnon EF, Martin RW, et al. Obstetric challenges of massive obesity complicating pregnancy. J Perinatol 1994;14:10 – 4. [9] Sheiner E, Levy A, Silverberg D, et al. Pregnancy after bariatric surgery is not associated with adverse perinatal outcome. Am J Obstet Gynecol 2004;190:1335– 40. [10] Raymond R. Hormonal status, fertility, and pregnancy before and after bariatric surgery. Crit Care Nurs Q 2005;28:263– 8. [11] Martin LF, Finigan K, Nolan T. Pregnancy after adjustable gastric banding. Obstet Gynecol 2000;95:927–30. [12] Woodard C. Pregnancy following bariatric surgery. J Perinat Neonatal Nurs 2004;18:329 – 40. [13] Wittgrove AC, Jester L, Wittgrove P, Clark GW. Pregnancy following gastric bypass for morbid obesity. Obes Surg 1998;8:461– 6. [14] Gurewitsch ED, Smith-Levitin M, Mack J. Pregnancy following gastric bypass surgery for morbid obesity. Obstet Gynecol 1996;88:658 – 61. [15] Printen KJ, Scott D. Pregnancy following gastric bypass for the treatment of morbid obesity. Am Surg 1982;48:363–5. [16] Richards DS, Miller DK, Goodman GN. Pregnancy after gastric bypass for morbid obesity. J Reprod Med 1987;32:172– 6. [17] Rand CS, Macgregor AM. Medical care and pregnancy outcome after gastric bypass surgery for obesity. South Med J 1989;82:1319 –20. [18] Dixon JB, Dixon ME, O’Brien PE. Pregnancy after lap-band surgery: management of the band to achieve healthy weight outcomes. Obes Surg 2001;11:59 – 65. [19] Ramirez MM, Turrentine MA. Gastrointestinal hemorrhage during pregnancy in a patient with history of vertical-banded gastroplasty. Am J Obstet Gynecol 2001;173:1630 –1. [20] Granstrom L, Granstrom L, Backman L. Fetal growth retardation after gastric banding. Acta Obstet Gynecol Scand 1990;69:533– 6. [21] Haddow JE, Hill LE, Kloza EM, Thanhauser D. Neural tube defects after gastric bypass. Lancet 1986;1:1330. [22] Martin L, Chavez GF, Adams MJ Jr, et al. Gastric bypass surgery as maternal risk factor for neural tube defects. Lancet 1988;1:640 –1. [23] Marceau P, Kaufman D, Biron S, et al. Outcome of pregnancies after biliopancreatic diversion. Obes Surg 2004;14:318 –24. [24] Grange DK, Finlay JL. Nutritional vitamin B12 deficiency in a breastfed infant following maternal gastric bypass. Pediatr Hematol Oncol 1994;11:311– 8. [25] Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol 2004;103:219 –24. [26] Waller DK, Mills JL, Simpson JP, et al. Are obese women at higher risk for producing malformed offspring? Am J Obstet Gynecol 1994; 170:541– 8. [27] Werler MM, Louik C, Shapiro S, et al. Prepregnant weight in relation to risk of neural tube defects. JAMA 1996;275:1089 –92. [28] Deitel M, Stone E, Kassam HA, et al. Gynecologic-obstetric changes after loss of massive excess weight following bariatric surgery. J Am Coll Nutr 1998;7:147–53. [29] Kakarla N, Dailey C, Marino T, et al. Pregnancy after gastric bypass surgery and internal hernia formation. Obstet Gynecol 2005;105: 1195– 8.
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Discussion Corrigan McBride, M.D. (Omaha, NE): The number of bariatric surgical procedures in this country is growing every year. ASBS estimates there will be over 200,000 gastric bypasses performed in 2006; 80% to 90% of the patients who are considering surgery tend to be female, and the mean age in most large studies ranges from about 38 years to 42 years so they are certainly in their reproductive ages. The authors today presented a retrospective study of 2,432 bariatric surgery patients. They do maintain a database that they update regularly with clinic records, telephone calls, and surveys according to the manuscript. And all of these data are prospectively collected. They were able to identify 34 patients who had pregnancy after bariatric surgery, and they divided these patients into 2 groups. An early group became pregnant in the first year and a late group who delayed their pregnancy until after 1 year. Because of the increasing information that is available to the patients on the Internet in the lay press, most of us now get these questions very commonly from our prospective patients, so I think this is a very important topic to touch on. But I do have several questions: first, you did not provide any data on whether or not these were first pregnancies or whether they were third, fourth, or fifth pregnancies. It would be interesting to know how post– bariatric surgery pregnancies compared with pre– bariatric surgery pregnancies. Second, compliance is a major problem in the bariatric surgical population. If you recommend that they wait 1 year, but they get pregnant anyway in that first year, does this indicate that they will be noncompliant with your other recommendations, such as vitamins, diet, exercise, and follow-up? In other words, how many pregnant patients are there that you do not know about because you have lost these people to follow-up? And finally, because the patients’ primary motivator for surgery has been weight loss and improve their health, what impact did these pregnancies have on their final excess body weight loss, BMI, and the resolution of their preoperative comorbidities? Kai Nishi, M.D. (Los Angeles, CA): The literature suggests that prenatal vitamins be given on top of the standard regimen of B12 and multivitamins given to postbypass patients. Do you recommend this? Tuoc Dao, M.D. (Dallas, TX): In regards to your first question about the number of pregnancies these patients had, I did review that data in these women. For the majority of the patients, this was their first pregnancy. Many of these women had infertility problems related to their obesity, and they had difficulties becoming pregnant before their weight loss. Some women during their interview also stated that infertility problems were one of the reasons they pursued weight-loss surgery. After significant weight loss, their menstrual cycles can regulate and increase their fertility and ability to conceive. There were 5 patients in the study that had prior pregnancies. When comparing prebariatric pregnancies to postbariatric pregnancies, these women after their gastric-bypass
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surgery did have a decreased incidence of preeclampsia, pregnancy induced hypertension, and gestational diabetes. Patients had less complications related to their pregnancy after their weight loss. As far as noncompliance, that is always an issue with our patients. The only thing we can do is provide good information and counseling to our patients about bariatric surgery and the importance of compliance to ensure successful weight loss long term. At our institution, we have a program in place for long-term follow-up with our patients. We have outpatient appointments at regular intervals. We also continue to send out letters, surveys, and make telephone calls to maintain contact with our patients. Because a number of patients will inevitably be lost to follow-up, it is important that others in the medical community be aware of these issues as well. It is difficult to know the exact number of patients that have become pregnant after their gastric bypass, but it is most likely an underestimated number. Because more patients are undergoing Roux-en Y gastric-
bypass surgery, these issues will become more common and prevalent. Overall, the pregnancies did not negatively affect the patients’ ability to lose weight in both groups of patients. On average, their final weight loss from the initial time of surgery was 99 lb for the early group and 113 lb for the late group. The final BMI was also similar in both the early and late groups (33 versus 30). They were still able to experience the same benefits as other nonpregnant gastric-bypass patients. For a majority of the women, their comorbidities, including hypertension and diabetes, did resolve after significant weight loss. There were a small percentage of patients, 5% to 10%, which failed surgical treatment. They were unable to maintain their weight loss long term. Dr Nishi, it is recommended that patients take prenatal vitamins in addition to their standard supplements of B12 and multivitamins after they become pregnant. These prenatal vitamins include folate, which is important for fetal growth and prevention of birth defects.