969 Correlation between low pre-pregnancy body mass index and adverse perinatal outcomes

Abstract

The aim of this study is to determine if a low pre-pregnancy BMI, specifically <18.5 (underweight) leads to adverse intrapartum and neonatal outcomes, primarily rate of cesarean delivery. After Baylor College of Medicine IRB was obtained, charts of women with who delivered between January 1, 2011 to January 1, 2018 at Ben Taub General Hospital and Texas Children’s Hospital – Pavilion for Women were reviewed. Demographic, intrapartum and postpartum variables were recorded including age, race, parity, mode of delivery, and neonatal outcomes. 71, 134 charts were available for review. Means and standard deviations were used to analyze demographic variables and chi square analysis was used to compare study groups. Of the greater than 70, 000 charts available for review, 1, 115 women had a pre-pregnancy BMI of less than 18.5. Of these women, 198 (17.7%) underwent cesarean delivery. Contrarily, 60, 097 women had a pre-pregnancy BMI of greater than 18.5 (normal weight, overweight, obese) with a cesarean delivery rate of 15% (p=0.040). Additionally, neonatal outcomes such as fetal growth restriction (FGR) were significantly impacted by low pre-pregnancy BMI, with greater than double the rates in underweight women. While much focus is placed on adverse maternal outcomes in higher BMI strata, there is also significant potential for poor outcomes in underweight women. There has previously been a paucity of data investigating women in this cohort, however our large study group and findings demonstrate the need to focus on appropriate weight and weight gain for these women during the antenatal period to decrease cesarean delivery rates and improve perinatal prognosis for both mother and infant.