Effects of Weight Gain on Delivery Outcomes in an Obese Pregnant Population [17D

Abstract

INTRODUCTION: The 2009 Institute of Medicine guidelines recommend 11-20 pounds weight gain for all pregnant women with a BMI ≥30. This study examines the effect of weight gain/loss on delivery outcomes in relation to class of obesity. METHODS: A retrospective cohort of 1,440 women receiving care at a large Medicaid clinic from 2013-2016 with pre-gravid BMI ≥30 was reviewed. Eligible women were non-smokers with a singleton pregnancy initiating care prior to 20 weeks. Multinomial logistic regression analysis compared gestational weight change to primary outcome of birth-weight percentile and secondary outcome of delivery type. RESULTS: Inclusion criteria were met by 889 women, with 485 in Class 1 (BMI 30-34.9), 218 in Class 2 (BMI 35-39.9), and 186 in Class 3 (BMI ≥40). Class 1 patients that lost weight were more likely to have a small-for-gestational-age (SGA) infant (P=.040) compared to Class 1 patients who had recommended weight gain. Class 2 and 3 patients had no statistically significant increase in SGA infants with weight loss or weight gain below recommendations. Class 2 patients that gained above recommendations were more likely to have a C-section during labor (P<.001) while Class 3 patients that gained above recommendations were more likely to have a scheduled C-section (P=.010). CONCLUSION: Class 2 and Class 3 mothers may benefit from less weight gain than current recommendations without increasing their risk of SGA infants. Further research is needed to ascertain if weight gain recommendations should be stratified based on obesity class.