Hypertensive Disorders of Pregnancy and Maternal Cardiovascular Disease Risk Factor Development: An Observational Cohort Study

Abstract

Background: Women with a history of hypertensive disorders of pregnancy (HDP) are nearly twice as likely to develop cardiovascular disease (CVD) as those who are normotensive during pregnancy. However, the emergence of CVD risk factors after HDP is less well-understood.

Objective: To identify associations between HDP and maternal CVD risk factors and chart the trajectory of risk factor development after pregnancy.

Design: Observational cohort study.

Setting: United States.

Participants: 58 671 parous NHS II (Nurses' Health Study II) participants who did not have CVD or risk factors of interest at baseline.

Measurements: Women were followed for self-reported physician diagnosis of chronic hypertension and hypercholesterolemia and confirmed type 2 diabetes mellitus (T2DM) from their first birth through 2013; mean follow-up ranged from 25 to 32 years across these end points. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs, with adjustment for prepregnancy confounders.

Results: Compared with women who were normotensive during pregnancy, those with gestational hypertension (2.9%) or preeclampsia (6.3%) in their first pregnancy had increased rates of chronic hypertension (HRs, 2.8 [95% CI, 2.6 to 3.0] and 2.2 [CI, 2.1 to 2.3], respectively), T2DM (HRs, 1.7 [CI, 1.4 to 1.9] and 1.8 [CI, 1.6 to 1.9], respectively), and hypercholesterolemia (HRs, 1.4 [CI, 1.3 to 1.5] and 1.3 [CI, 1.3 to 1.4], respectively). Although these women were more likely to develop CVD risk factors throughout follow-up, the relative risk for chronic hypertension was strongest within 5 years after their first birth. Recurrence of HDP further elevated risks for all end points.

Limitation: Participants self-reported HDP.

Conclusion: Women with HDP in their first pregnancy had increased rates of chronic hypertension, T2DM, and hypercholesterolemia that persisted for several decades. These women may benefit from lifestyle intervention and early screening to reduce lifetime risk for CVD.

Primary funding source: National Institutes of Health.

Figure 1.. Multivariable-adjusted cumulative incidence of chronic hypertension, type 2 diabetes mellitus, and hypercholesterolemia by hypertensive disorder in first pregnancy through 40 years since first birth.

Curves are obtained at the mean and mode values for the following continuous and categorical covariates, respectively : age at first birth (27 years), age in 1989 (35 years), race/ethnicity (white), parental education (12 years), physical activity at ages 18–22 (1–3 months/year), pre-pregnancy smoking (never), pre-pregnancy body mass index (normal weight: 18.5–24.9 kg/m²), pre-pregnancy alcohol consumption (≤1 drink/week), pre-pregnancy Alternative Healthy Eating Index (AHEI) score (3^rd quintile), pre-pregnancy oral contraceptive use (≥4 years), family history of chronic hypertension (present; chronic hypertension model only) and family history of type 2 diabetes mellitus (absent; type 2 diabetes mellitus model only). * P-value <0.001 from a global test of the difference in the distribution of time to risk factor development between hypertensive disorder in first pregnancy exposure groups. IQR = interquartile range.