Preeclampsia Risk in Women Exposed in Utero to Diethylstilbestrol

To assess whether preeclampsia risk is elevated in pregnancies of diethylstilbestrol (DES)-exposed daughters.This study used data from the National Cancer Institute DES Combined Cohorts Follow-up Study. A total of 285 preeclampsia cases (210 exposed and 75 unexposed) occurred in 7,313 live births (4,759 DES exposed and 2,554 unexposed). Poisson regression analysis estimated relative risks and 95% confidence intervals (CI) for preeclampsia adjusted for age at the index pregnancy, parity, education, smoking, body mass index, year of diagnosis, and cohort.In utero DES exposure was associated with nearly a 50% elevation in preeclampsia risk. Adjustment for preeclampsia risk factors attenuated the relative risk slightly (1.42, 95% CI 1.04-1.94). The excess risk with DES was concentrated among women who developed preeclampsia in their first pregnancies (relative risk 1.81, 95% CI 1.17-2.79), who were exposed before 15 weeks of gestation (relative risk 1.57, 95% CI 1.11-2.23), and who were treated with magnesium sulfate (relative risk 2.10, 95% CI 0.82-5.42). Among DES-exposed women who had a prior hysterosalpingogram, preeclampsia prevalence was higher in those with uterine abnormalities (12.4%) than in those without (7.7%).These data suggest that in utero exposure to DES is associated with a slightly elevated risk of preeclampsia, and that one possible biological mechanism involves uterine abnormalities.