Obstetrical and neonatal outcomes of pregnancies following gastric bypass surgery: a retrospective cohort study in a French referral centre.

The objective of this study was to analyze obstetrical and neonatal outcomes following Roux en Y Gastric Bypass procedures (RYGBP).A retrospective cohort study was conducted in a single French tertiary perinatal care and bariatric center. The study involved 24 pregnancies, following RYGBP (exposed group) and two different control groups (non-exposed groups). A body mass index (BMI)-matched control group included 120 pregnancies matched for age, parity, and pregnancy BMI. A normal BMI control group included 120 pregnancies with normal BMI (18.5-24.9 kg/m(2)), matched for age and parity. Hospital data were reviewed from all groups in the same 6-year period. Obstetrical and neonatal outcomes after RYGB were compared, separately, to the two different-matched control groups.The median interval from RYGBP to conception was 26.6 (range: 3-74) months. Rates of perinatal complications did not differ significantly between the RYGBP group and normal BMI and BMI-matched controls groups. The rate of Cesarean section before labor was higher in the RYGBP patients than in the normal BMI control group (25\% vs. 9.3\% respectively, p = 0.04). Weight gain was lower in the RYGBP patients than normal BMI control group (5.8 kg vs. 13.2 kg respectively, p < 0.0001). Birthweight was also lower in the RYGBP group than those in normal BMI and BMI-matched controls groups (2,948.2 g vs. 3,368.2 g and 3,441.8 g, respectively, p < 0.0001).RYGBP surgery was associated with reduced birthweight, suggesting a possible role of nutritional growth restriction in pregnancy.