Abstract P313: Cumulative Birth History and Incident Hypertension 2-7 Years After a First Birth

Abstract

Background: Women with adverse pregnancy outcomes (APOs) have excess cardiovascular (CV) risk, often presenting as chronic hypertension (HTN) after delivery. The accrual of CV risk according to complete birth history is understudied. Methods: The nuMoM2b Heart Health Study is a prospective cohort of nulliparous individuals at 8 US sites followed from the 1 st trimester (baseline) of their 1 st pregnancy to a CV visit 2-7 years later. This analysis (n=3483) includes those with up to 2 births delivered before the CV visit; those with HTN before the 1 st pregnancy were excluded. APOs (hypertensive disorders of pregnancy, gestational diabetes, preterm birth, birthweight <5 th %ile, stillbirth) were adjudicated via medical record (70%) or self-report (30%). Individuals were analyzed by APO history; those with no APOs were the referent (Table). HTN status 2-7 years after baseline was evaluated (BP ≥130/80 mmHg or medication). Multivariable logistic regression estimated the association between APO history and incident HTN (aOR; iHTN) accounting for baseline demographics, CV risk factors, and race/ethnicity, understood as a social construct, given known disparities in APOs and CVD. Results: Individuals with no APO in either birth had the lowest iHTN (n=1224; 13.2%; Table). Those with recurrent APO (n=227; iHTN 33.0%) and APO in the 1 st birth and no later births (n=534; iHTN 36.7%) had the highest iHTN. Accounting for covariates, those with a 1 st birth APO and no later births had 2.54-fold (95% CI 1.93, 3.34) higher iHTN. Those with APOs in both births and APO in only the 2 nd birth had 2.12-2.13-fold increased odds of iHTN. Those with an APO in the 1 st birth and an uncomplicated 2 nd birth had modestly elevated iHTN (aOR 1.35, 95% CI 0.99, 1.85). Conclusion: The risk of iHTN after a 1 st birth differs depending upon the cumulative birth history, with recurrent APO or APO in a 1 st birth with no later births portending the highest risk for iHTN. Longer term follow-up is needed to assess the contribution of additional reproductive factors to loss of CV health.