Gestational Weight Gain and Pregnancy Complications in a High-Risk, Racially and Ethnically Diverse Population

Background: Evidence used to guide the current Institute of Medicine (IOM) gestational weight gain (GWG) recommendations is largely derived from studies of European descent, and as such the guidelines are the same for all races and ethnicities. The guidelines are also the same for prepregnancy obesity classes I through III. Objective: Considering these literature gaps, we aim to (1) determine the association between the IOM GWG guidelines and three common pregnancy complications: preeclampsia, gestational diabetes mellitus, and cesarean delivery in a racially and ethnically diverse population; and (2) assess whether the association between GWG and pregnancy complications differs by race/ethnicity or prepregnancy body mass index (BMI) categories, particularly obesity classes I through III. Methods: To address these aims, we analyzed data from the Boston Birth Cohort. We calculated GWG using data from electronic medical records or, when missing, from a postdelivery questionnaire. We examined GWG continuously and categorically using the IOM formula. Results: Of the 5,568 women included, 54.5% met the IOM criterion for excessive GWG. Compared to women who had adequate GWG, women who gained excessive weight had 1.65 (95% confidence interval [CI] 1.27-2.14) times greater odds of preeclampsia; 1.68 (95% CI 1.15-2.46) times greater odds of gestational diabetes; and no significant change in odds of cesarean delivery (odds ratio [OR] = 1.14, 95% CI 0.99-1.31). Associations did not differ by race, ethnicity, or prepregnancy BMI categories including comparisons of obesity class I versus II or III (all p-values for interaction >0.05). Conclusions: In this racially and ethnically diverse population, excessive GWG was associated with higher odds of preeclampsia, gestational diabetes, and nonsignificantly, with cesarean delivery. Associations did not differ appreciably by race, ethnicity, or prepregnancy BMI categories. Our results support the relevance of the IOM GWG recommendations in racially and ethnically diverse populations, and in women in the higher prepregnancy obesity classes.