Effects of Gestational Weight Gain on Delivery Outcomes in an Obese, Low-Income Population.

Objective: To examine the effects of weight gain/loss on delivery outcomes stratified by class of obesity in an obese, low-income, predominantly minority population.

Methods: A retrospective review of a cohort of 1428 women receiving care at a large Medicaid clinic from 2013 to 2016 with pregravid body mass index ≥30 was conducted. Multinomial logistic regression analysis was used to compare differences in gestational weight change to the primary outcomes of birth-weight percentile and delivery type and secondary outcomes of preterm delivery, preterm labor, gestational diabetes mellitus, and gestational hypertension.

Results: Obesity class 1 patients who lost weight were more likely to have a small-for-gestational-age (SGA) infant compared with those who had recommended weight gain. Obesity classes 2 and 3 patients had no statistically significant increase in SGA infants with weight loss or weight gain below current recommendations. Obesity classes 1 and 2 patients with weight loss had a statistically significant increase in both preterm delivery and preterm labor; however, class 3 patients did not. Obesity class 3 patients who lost weight were significantly more likely to have gestational diabetes mellitus.

Conclusions: Obesity class 3 women may benefit from less weight gain than current recommendations without increasing their risk of SGA infants or preterm birth, especially if gestational diabetes mellitus is present.