Impact of Gestational Weight Gain Recommendations for Obese Women on Neonatal Morbidity.

Introduction: In 2013, the American College of Obstetricians and Gynecologists (ACOGs) developed gestational weight gain guidelines to minimize the risks associated with obesity during pregnancy. However, a growing body of evidence suggests that current recommendations should be revised for obese women.

Objective: The objective of this study is to assess the impact of gestational weight gain recommendations for obese women (body mass index ≥ 30 kg/m) on neonatal and maternal outcomes in Quebec.

Study Design: Secondary analysis of the QUARISMA trial was performed including obese women who delivered a full-term singleton in cephalic presentation from 2008 to 2011 in Quebec. Outcomes assessed were composite risks of major neonatal and maternal complications, minor neonatal and maternal complications, as well as obstetrical interventions. Outcomes were compared between weight gain recommendations (reference group) and three weight gain/loss categories using logistic regressions. In second analysis, obese women were stratified by obesity class.

Results: Among the 16,808 eligible obese women, 605 lost weight during pregnancy, 2,665 gained between 0 and 4.9 kg, 4,355 gained weight within the recommendations (5-9.09 kg), and 9,183 gained at least 9.1 kg. Results showed a significant reduction in major neonatal morbidity (adjusted odds ratio [aOR] = 0.69, 95% confidence interval [CI] = 0.51-0.94), minor maternal morbidity (aOR = 0.79, 95%CI = 0.67-0.93), and assisted vaginal delivery (aOR = 0.82, 95%CI = 0.68-0.99) among women who gained 0 to 4.9 kg compared with the reference group. Cesarean delivery and preeclampsia/eclampsia were significantly reduced with weight loss (aOR = 0.76, 95%CI = 0.64-0.89 and 0.58, 95%CI = 0.42-0.78) compared with the reference group. Weight gain above recommendations was associated with an increased risk of minor neonatal morbidity, major and minor maternal morbidity, as well as cesarean delivery.

Conclusion: Compared with a weight gain within the recommendations, a gestational weight gain/loss of less than 5 kg in obese women is associated with a reduced risk of major neonatal morbidity, minor maternal morbidity, preeclampsia/eclampsia, cesarean delivery, and assisted vaginal delivery. Guidelines on gestational weight gain for obese women should be updated.

Key Points: · Gestational weight gain/loss of less than 5 kg reduces the risk of perinatal complications.. · As suggested by ACOG recommendations, guidelines for obese women should be updated.. · Recommendations stratified by obesity class should be included in revised guidelines..