Racial and Ethnic Disparities in Stillbirth among Pregnant Women with Obesity

Objective The aim of this study was to examine the relationship between obesity and risk of stillbirth among pregnant women with obesity in the United States, with a focus on racial and ethnic disparities. Study Design We conducted a retrospective cross-sectional analysis of birth and fetal data from the 2014 to 2019 National Vital Statistics System (N = 14,938,384 total births) to examine associations between maternal body mass index (BMI) and risk of stillbirth. Cox's proportional hazards regression model was used to compute adjusted hazard ratios (HR) as a measure of risk of stillbirth in relation to maternal BMI. Results The stillbirth rate was 6.70 per 1,000 births among women with prepregnancy obesity, while the stillbirth rate among women with a normal (nonobese) prepregnancy BMI was 3.85 per 1,000 births. The risk of stillbirth was greater among women with obesity compared with women without obesity (HR: 1.39; 95% confidence interval [CI]: 1.37-1.41). Compared with non-Hispanic (NH) Whites, women identifying as NH-other (HR: 1.66; 95% CI: 1.61-1.72) and NH-Black (HR: 1.31; 95% CI: 1.26-1.35) were at higher risk of stillbirth, while Hispanic women had a decreased likelihood of stillbirth (HR: 0.38; 95% CI: 0.37-0.40). Conclusion Obesity is a modifiable risk factor for stillbirth. Public health awareness campaigns and strategies targeting weight management in women of reproductive age and racial/ethnic populations at highest risk for stillbirth, are needed. Key Points Stillbirth rates differ by race and ethnicity. Risk of stillbirth was greatest among women with obesity. Stillbirth rates rise with ascending prepregnancy BMI.