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.