Body Mass Index, Weight Gain, and Hypertensive Disorders in Pregnancy

This study examines the interrelationship between gestational weight gain, pre-pregnancy body mass index (BMI), race/ethnicity, and their association with hypertensive disorders during pregnancy (HDP).

Data from the 2004-2011 national Pregnancy Risk Assessment Monitoring System (PRAMS) were analyzed. Women with singleton live births were included in the analysis (N = 270,131). Gestational weight gain was categorized reflecting the Institute of Medicine (IOM) weight gain recommendation (no gain/weight loss; ≤11, 12-14; 15-25; 26-35; ≥36 pounds). Pre-pregnancy BMI (underweight; normal; overweight; obese) and race/ethnicity (non-Hispanic (NH) White, NH-Black, Hispanic, and NH-other) were examined. Hypertensive disorders during pregnancy were dichotomized (HDP; no HDP). Data were stratified by BMI and race/ethnicity, and multiple logistic regression analysis was conducted to generate odds ratios and 95% confidence intervals (CIs).

Compared to normal and overweight women who gained the IOM recommended weight, higher odds of HDP was observed in those who gained ≥36 pounds regardless of their race/ethnicity. Among obese NH-White (odds ratio (OR) = 1.29, 95% CI = 1.11, 1.50) and Hispanic women (OR = 1.64, 95% CI = 1.05, 2.54), the odds of HDP was higher among those who gained 25-35 pounds and those who gained ≥36 pounds (OR = 1.59, 95% CI = 1.37, 1.85) and (OR = 2.20, 95% CI = 1.41, 3.44), respectively. However, for NH-Black obese women, higher odds of HDP was observed among those who gained ≥36 pounds (OR = 1.34, 95% CI = 1.04, 1.73).

Although there are some ethnic/racial variations, pregnant women who exceeded gestational weight gain recommendations are at increased risk of HDP. Health care providers should consider the interrelationship between pre-pregnancy gestational weight gain (GWG) and BMI when counseling patients regarding HDP.