Maternal, Fetal and Infant outcomes Associated with Bariatric Surgery

Objective: The purpose of this study was to determine the association between bariatric surgery and maternal, fetal and infant outcomes. Summary Background Data: Obesity during pregnancy is a risk factor for adverse pregnancy outcomes. Bariatric surgery is the most effective weight loss treatment but the impact of bariatric surgery on pregnancy outcomes remains poorly characterised. Methods: This was a population-based, matched cohort study of prospective databases in Ontario, Canada. Patients with obesity who received bariatric surgery from 2010 to 2016 and subsequently became pregnant matched on multiple factors to non-surgical pregnant patients with obesity. The primary outcomes of interest were the incidence included of gestational diabetes, preeclampsia/HELLP syndrome, small for gestational age (SGA), large for gestational age (LGA), and a composite of severe fetal/infant morbidity/mortality. Multivariable regression evaluated outcomes. Results: 680 patients who underwent bariatric surgery and later became pregnant were matched to 2002 pregnant patients with obesity. Gestational diabetes occurred in 8.7% of the surgery group and 18.8% of the non-surgical group (adjusted OR (aOR) 0.29, 95%CI 0.21-0.40, P <0.001). A lower incidence of preeclampsia/HELLP was observed post-surgery (aOR 0.20, 95%CI 0.13-0.31, P <0.001). Bariatric surgery impacted SGA (aOR 2.74, 95%CI 2.04–3.70, P <0.001) and LGA (aOR 0.25, 95%CI 0.18-0.36, P <0.001). There were no observed associations between bariatric surgery and any adverse fetal or infant outcomes. A lower composite severe fetal/infant morbidity/mortality was observed post-surgery (aOR 0.73, 95%CI 0.54-0.97, P <0.05). Conclusions: Pregnancy after bariatric surgery appears safe and was associated with a reduced risk of several obesity related adverse pregnancy outcomes.