Pregnancy and fertility following bariatric surgery: a systematic review.

CONTEXT: Use of bariatric surgery has increased dramatically during the past 10 years, particularly among women of reproductive age.

OBJECTIVES: To estimate bariatric surgery rates among women aged 18 to 45 years and to assess the published literature on pregnancy outcomes and fertility after surgery.

EVIDENCE ACQUISITION: Search of the Nationwide Inpatient Sample (1998-2005) and multiple electronic databases (Medline, EMBASE, Controlled Clinical Trials Register Database, and the Cochrane Database of Reviews of Effectiveness) to identify articles published between 1985 and February 2008 on bariatric surgery among women of reproductive age. Search terms included bariatric procedures, fertility, contraception, pregnancy, and nutritional deficiencies. Information was abstracted about study design, fertility, and nutritional, neonatal, and pregnancy outcomes after surgery.

EVIDENCE SYNTHESIS: Of 260 screened articles, 75 were included. Women aged 18 to 45 years accounted for 49% of all patients undergoing bariatric surgery (>50,000 cases annually for the 3 most recent years). Three matched cohort studies showed lower maternal complication rates after bariatric surgery than in obese women without bariatric surgery, or rates approaching those of nonobese controls. In 1 matched cohort study that compared maternal complication rates in women after laparoscopic adjustable gastric band surgery with obese women without surgery, rates of gestational diabetes (0% vs 22.1%, P < .05) and preeclampsia (0% vs 3.1%, P < .05) were lower in the bariatric surgery group. Findings were supported by 13 other bariatric cohort studies. Neonatal outcomes were similar or better after surgery compared with obese women without laparoscopic adjustable gastric band surgery (7.7% vs 7.1% for premature delivery; 7.7% vs 10.6% for low birth weight, P < .05; 7.7% vs 14.6% for macrosomia, P < .05). No differences in neonatal outcomes were found after gastric bypass compared with nonobese controls (26.3%-26.9% vs 22.4%-20.2% for premature delivery, P = not reported [1 study] and P = .43 [1 study]; 7.7% vs 9.0% for low birth weight, P = not reported [1 study]; and 0% vs 2.6%-4.3% for macrosomia, P = not reported [1 study] and P = .28 [1 study]). Findings were supported by 10 other studies. Studies regarding nutrition, fertility, cesarean delivery, and contraception were limited.

CONCLUSION: Rates of many adverse maternal and neonatal outcomes may be lower in women who become pregnant after having had bariatric surgery compared with rates in pregnant women who are obese; however, further data are needed from rigorously designed studies.