Outcomes of pregnancy after bariatric surgery: results of a French matched-cohort study

Abstract

While the benefits of bariatric surgery (BS) on pregnancy outcomes have been demonstrated for women compared with matched controls on presurgery body mass index (pB-BMI), data are lacking and those benefits are uncertain compared with matched controls on prepregnancy BMI (pP-BMI). Our study aimed to evaluate outcomes (obstetrical and neonatal) of single pregnancy in women previously exposed to BS compared with women unexposed to BS matched on pB-BMI and pP-BMI. Retrospective matched cohort study from 2 observational studies of pregnant women conducted in a French administrative county (Finistère). From April 1, 2015 to January 31, 2019, pregnant women with previous BS (n = 52) were included and compared with 2 different control groups as follows: group A (n = 104), matched for pB-BMI, age, and parity; and group B (n = 104), matched for pP-BMI, age, and parity. In women exposed to BS, mean age was 27.1 (±4.9) years and pB-BMI was 46.0 (±4.6) kg/m2. Operated women differed significantly from group A but not from group B for pP-BMI (29.4 ± 6.1 versus 45.3 ± 4.5 group A versus 28.6 ± 6.6 group B) and gestational diabetes (12.0% versus 44.0% group A versus 17.0% group B), respectively. In the group of women exposed to BS, birth weight (g) was significantly lower (2960 ± 545 versus 3381 ± 735 group A versus 3310 ± 645 group B) and large-for-gestational-age infants less frequent (0% versus 13% group A versus 8% group B). Bariatric surgery reduced risks of excessive fetal growth and gestational diabetes with a trend for a higher risk of small-for-gestational-age, despite matching on pP-BMI suggesting a risk associated to BS and solely to previous surgery-induced weight loss.