Abstract MP093: Preterm Delivery is Associated with Maternal Cardiovascular Risk Factors

Abstract

Background: Women with a history of delivering a child preterm have a higher risk of cardiovascular disease (CVD). We sought to evaluate whether these women are also at higher risk of developing CVD risk factors after adjustment for multiple pre-pregnancy risk factors. Methods: We examined the association between preterm delivery (<37 weeks) and development of subsequent chronic hypertension, hypercholesterolemia, and type 2 diabetes mellitus (T2DM) among 59,315 women in the Nurses’ Health Study II. We restricted our study population to parous women who did not experience gestational diabetes or a hypertensive disorder in their first pregnancy and were free of CVD risk factors of interest and events at baseline. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between preterm delivery in first pregnancy and each CVD risk factor. We additionally investigated the association between preterm delivery over a woman’s entire reproductive history and CVD risk factors. Results: Compared to women who delivered their first pregnancy at term, preterm delivery was associated with HRs of 1.13 (95% CI: 1.07, 1.19) for chronic hypertension, 1.06 (95% CI: 1.02, 1.11) for hypercholesterolemia, and 1.21 (95% CI 1.08, 1.35) for T2DM, after adjusting for age, race/ethnicity, parental education, and other pre-pregnancy risk factors (e.g., BMI, smoking, family history of chronic hypertension and T2DM). These associations were stronger in the very preterm group (<32 weeks) than in the moderate preterm group (≥32 to <37 weeks). The risk was highest in the first 10 years after a preterm first birth with HRs of 1.45 (95% CI: 1.23, 1.71) for chronic hypertension, 1.13 (95% CI: 1.02, 1.25) for hypercholesterolemia, and 2.14 (95% CI: 1.33, 3.45) for T2DM. When investigating a woman’s entire reproductive history, we found that, compared to women with at least two births all of which were at term, women with a preterm first birth were at increased risk of chronic hypertension regardless of the gestation lengths of future pregnancies, while women with a preterm first birth and no future births had the highest risk of T2DM. Conclusions: Women with a history of preterm delivery have higher risk of developing chronic hypertension, hypercholesterolemia, and T2DM after pregnancy. These results suggest potential benefits of including preterm delivery in CVD risk scores and screening.