Maternal coronary heart disease and mortality following hypertensive disorders of pregnancy and/or diabetes.

BACKGROUND

Pre-pregnancy hypertension (HTN), hypertensive disorders of pregnancy (HDP), and diabetes have been linked to increased risk of post-pregnancy coronary heart disease (CHD) and all-cause mortality, but few studies have investigated their cumulative impact. This study aimed to assess the potential relationship between pre-pregnancy HTN, HDP, and diabetes and their cumulative impact on maternal cardiovascular outcomes defined as incident CHD and all-cause mortality within 5 years of delivery and over the entire study period (up to 14 years after delivery).

METHODS

This retrospective cohort study included 430,545 women aged 12-49 with ≥ 1 singleton, live birth in South Carolina (2004-2016) including non-Hispanic White (NHW; 59.2%), non-Hispanic Black (NHB; 31.4%), and Hispanic (9.4%) women. Birth certificate and hospitalization/emergency department (ED) visit data defined pre-pregnancy HTN, HDP (preeclampsia, eclampsia, gestational HTN), and diabetes (pre-pregnancy, gestational). Hospitalization/ED visit and death certificate data defined incident CHD and all-cause mortality. Covariate-adjusted Cox proportional hazard models were used to assess associations between CHD and mortality by exposure.

RESULTS

After adjustment for covariates relative to women without any of the three conditions (diabetes, pre-pregnancy HTN, HDP), incident CHD risk was increased within 5 years of delivery for women with diabetes (HR = 1.57; 95% CI 1.28-1.92), HDP (HR = 1.85; 95% CI 1.60-2.15), HDP and diabetes (HR = 2.29; 95% CI 1.73-3.03), HDP and pre-pregnancy HTN (HR = 3.13; 95% CI 2.66-3.68), and all three conditions (HR = 4.87; 95% CI 3.95-6.01). All-cause mortality risk was increased for diabetes (HR = 1.34; 95% CI 1.01-1.78), HDP and pre-pregnancy HTN (HR = 1.53; 95% CI 1.15-2.03), and all three conditions (HR = 2.25; 95% CI 1.51-3.36), but not HDP or HDP and diabetes.

CONCLUSIONS

Within 5 years of delivery, incident CHD and all-cause mortality rates were highest for women with two or three conditions, specifically HDP, diabetes, and/or pre-pregnancy HTN, with all rates higher for NHB than NHW women. Thus, it is critical to implement clinical prevention strategies to improve risk factor screening and identification among women of child-bearing age.