Abstract 14953: Racial and Ethnic Disparities in Preterm Birth Among Individuals With Hypertensive Disorders of Pregnancy in the United States, 2020-2021

Introduction: Preterm birth (PTB) is a common adverse outcome in pregnancies complicated by hypertensive disorders of pregnancy (HDP). PTB and HDP are each associated with higher risk of cardiovascular disease (CVD) in both the pregnant individual and their offspring. Racial and ethnic disparities have been described individually in PTB and HDP but the frequency of PTB among individuals with HDP, and whether differences exist by maternal race and ethnicity, is not known.

Methods: We used cross-sectional data from the National Center for Health Statistics and included nulliparous individuals aged 15-44 years with a singleton, live birth who had new-onset HDP (gestational hypertension or preeclampsia) in the US in 2020 and 2021. We calculated the frequency of PTB (gestational age < 37 weeks) among those with HDP (%), overall and stratified by self-reported maternal race and ethnicity group (American Indian/Alaskan Native [AIAN], non-Hispanic Asian/Pacific Islander [API], Hispanic, non-Hispanic Black [NHB], non-Hispanic White [NHW]). We compared the frequency of PTB in each racial and ethnic group to the referent group (NHW) with age-standardized rate ratios (aRR).

Results: Among 302,817 individuals with HDP, 0.7% were AIAN, 0.8% API, 18.7% Hispanic, 15.5% NHB, and 57.2% NHW. The frequency of PTB among individuals with HDP was 17.6% (95% 17.4-17.8) in 2020 and 18.0% (17.8-18.2) in 2021. Significant racial and ethnic differences were observed in the frequency of PTB with HDP in 2020 and 2021 ( Table ). In 2021, compared with NHW individuals, AIAN (aRR 1.2 [1.0-1.4]), Hispanic (aRR 1.1 [1.1-1.2]), and NHB (aRR 1.4 [1.3-1.4]) individuals had a significantly higher risk of PTB with HDP.

Conclusions: In 2020-2021, nearly 1 out of 5 nulliparous individuals with HDP also experienced PTB. Identifying and addressing drivers of racial and ethnic differences in the co-occurrence of PTB and HDP may offer an opportunity to mitigate disparities in intergenerational CVD risk.