Pregnancy outcomes in women after bariatric surgery compared with obese and morbidly obese controls

OBJECTIVE: To estimate the rates of pregnancy outcomes of women after bariatric surgery relative to women in a control groups. METHODS: The study was a chart review. Presurgery and prepregnancy body mass index (BMI) were calculated for 70 patients who had undergone bariatric surgery and who had a subsequent singleton pregnancy. Four control patients were then randomly selected for each case patient: two with a BMI within 6 points of the average presurgery BMI and two with a BMI within 6 points of the average prepregnancy BMI. The primary outcomes were the rates of gestational diabetes or hypertensive disorders of pregnancy. RESULTS: There was a significant decrease in rate of gestational diabetes in bariatric surgery patients (0.0%) as compared with both control groups (morbidly obese 16.4%, obese 9.3%; corrected odds ratio (OR) _{morbidly obese} 0.04, with a 95% confidence interval [CI] 0.00-0.62, P<.01; corrected OR _obese 0.07, CI 0.00-1.20, P=.01). There was no significant difference in the rate of hypertensive disorders of pregnancy with bariatric surgery. Additionally, neonates were significantly more likely to be small for gestational age (SGA) in the bariatric surgery group (17.4%) than the morbidly obese group (5.0%) (OR 3.94, CI 1.47-10.53, P<.01). CONCLUSION: Bariatric surgery is associated with reduction in gestational diabetes in a subsequent pregnancy, but possibly at the expense of an increase in SGA neonates. LEVEL OF EVIDENCE: II.