Racial Differences in Adverse Pregnancy Outcomes and Incident Hypertension: A Mediation Analysis.

Area of Science:

• Reproductive Health
• Cardiovascular Health
• Health Disparities

Background:

• Adverse pregnancy outcomes (APOs) are linked to increased hypertension risk.
• Black women face higher rates of both APOs and hypertension compared to White women.
• The role of APOs in contributing to Black-White hypertension disparities is not well understood.

Purpose of the Study:

• To investigate whether APOs mediate the racial disparity in hypertension.
• To quantify the potential reduction in hypertension disparities if APO disparities were eliminated.

Main Methods:

• Prospective recruitment of nulliparous individuals in the nuMoM2b-HHS study across 8 US centers.
• Follow-up assessments 2-7 years postpartum to determine incident hypertension.
• Analysis using targeted maximum likelihood estimation to model the impact of eliminating APO disparities on Black-White hypertension differences.

Main Results:

• Higher incidence of APOs (hypertensive disorders of pregnancy, preterm birth, small-for-gestational age) observed in Black versus White participants.
• Incident hypertension was significantly higher in Black versus White individuals postpartum.
• Eliminating racial disparities in APOs could decrease the Black-White hypertension disparity by 13.9% to 18.2%.

Conclusions:

• Adverse pregnancy outcomes partially mediate the observed Black-White differences in hypertension.
• APOs represent a potential pregnancy-specific pathway contributing to racial disparities in hypertension.
• Targeting disparities in adverse pregnancy outcomes may help reduce long-term hypertension risk differences.