The effect of pregnancy before and/or after bariatric surgery on weight loss

Background: Women of childbearing age represent 31%-36% of patients undergoing bariatric surgery. However, the influence of pregnancy before or after bariatric surgery on surgery outcomes is unclear. Objectives: The aim of the present study was to compare the effect of pregnancy before and after bariatric surgery on overall weight loss. Setting: An academic center in the United States. Methods: All female patients who had a successful pregnancy between 2005 and 2014 were included. The window of inclusion was <= 3 years, either before or after surgery. Control patients included a cohort of female patients who had not been pregnant, matched on a 2:3 ratio for age, initial body mass index, type of procedure, and duration of follow-up. Results: A total of 62 patients delivered within 3 years either before or after surgery. Data were compared with a matched cohort of 92 patients who had never conceived. Mean age at surgery was 33.8 years, and mean body mass index at surgery was 48.2 kg/m(2). Laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, and adjustable gastric banding were performed in 75.9%, 12.9%, and in 11.0% of cases, respectively. After an average matched follow-up period of 43.9 months, percentage excess weight loss was 68.0% +/- 26.0% in the nonpregnant group compared with 53.0% +/- 25.0% in the pregnant group (P<.01). The percentage total weight loss was 24.0% +/- 11.0% in the study group compared with 31.0% +/- 12.0% in the matched cohort (P<.01). Multivariate analysis showed that pregnancy before bariatric surgery had a more negative effect on weight loss compared with patients who had never been pregnant (odds ratio: -3.8; 95% confidence interval, -6.6 to -1.0; P<.01). Conclusion: Pregnancy before bariatric surgery increases the likelihood of reduced weight loss after surgery. Patients wishing to conceive should be informed that weight loss outcomes may vary depending on the timing of pregnancy relative to bariatric surgery. (C) 2016 American Society for Metabolic and Bariatric Surgery. All rights reserved.