A Prospective Cohort Study of Prenatal Diethylstilbestrol Exposure and Cardiovascular Disease Risk

Prenatal exposure to diethylstilbestrol (DES), a prototype endocrine-disrupting chemical, is associated with risk for adverse reproductive outcomes and cancer in women. We investigated whether cardiovascular disease (CVD) risk might also be greater in women prenatally exposed to DES.

DES-exposed (n = 3941) and -unexposed (n = 1705) women participating in the Combined DES Cohort Follow-up Study were followed prospectively from 1994 to 2013. Prenatal DES exposure (or lack of exposure) was documented in the birth record or physician's note. Participants reported by questionnaire any "serious medical conditions requiring hospitalization, surgery or long-term treatment," including coronary artery disease (CAD), myocardial infarction (MI), and stroke. We sought physician's verification of self-reports and identified CVD deaths from the National Death Index. Hazard ratios (HRs) with 95% confidence intervals (CIs) from Cox proportional hazard regression models estimated associations between DES exposure and CVD incidence, adjusted for birth year, original cohort, and potential confounders.

In comparison of the exposed to the unexposed women, the HRs for reported conditions were 1.74 (95% CI, 1.03 to 2.93) for CAD, 2.20 (95% CI, 1.15 to 4.21) for MI, 1.01 (95% CI, 0.54 to 1.90) for stroke, and 1.31 (95% CI, 0.93 to 1.86) for the combined conditions (i.e., total CVD). The HRs were similar for verified outcomes (CAD, 1.72; MI, 2.67; stroke, 0.92; and total CVD, 1.25) and with additional adjustment for hypertension, diabetes, and high cholesterol (HRs: CAD, 1.67; MI, 2.04; stroke, 0.96; and total CVD, 1.24).

These data demonstrate associations in women who have prenatal DES exposure with CAD and MI, but not with stroke, which appear to be independent of established CVD risk factors.