Continued follow-up of pregnancy outcomes in diethylstilbestrol-exposed offspring

Objective: To evaluate long-term pregnancy experiences of women exposed to diethylstilbestrol (DES) in utero compared with unexposed women. Methods: This study was based on diethylstilbestrol-exposed daughters, the National Collaborative Diethylstylbistrol Adenosis cohort and the Chicago c ohort, and their respective nonexposed comparison groups. Subjects who coul d be traced were sent a detailed questionnaire in 1994 that contained quest ions on health history, including information on pregnancies and their outc omes. We reviewed 3373 questionnaires from exposed daughters and 1036 quest ionnaires from unexposed women. Results: The response rate was 88% among exposed and unexposed women. Dieth ylstilbestrol-exposed women were less likely than unexposed women to have h ad full-term live births and more likely to have had premature births, spon taneous pregnancy losses, or ectopic pregnancies. Full-term infants were de livered in the first pregnancies of 84.5% of unexposed women compared with 64.1% of exposed women identified by record review (relative risk [RR] 0.76 , confidence interval [CI] 0.72, 0.80). Preterm delivery of first births oc curred in 4.1% of unexposed compared with 11.5% of exposed women, and ectop ic pregnancies in 0.77% of unexposed compared with 4.2% of exposed women. S pontaneous abortion was reported in 19.2% of DES-exposed women compared wit h 10.3% in control women (RR 2.00, CI 1.54, 2.60). According to complete pr egnancy histories (many women had more than one pregnancy), preterm births were more common in DES-exposed women (19.4% exposed versus 7.5% unexposed (RR 2.93 CI 2.23, 3.86). Second-trimester spontaneous pregnancy losses were more common in DES-exposed women (6.3% versus 1.6%; RR 4.25, CI 2.36, 7.66 ). More first-trimester spontaneous abortions occurred in DES-exposed women than in controls (RR 1.31, CI 1.13, 1.53), and DES-exposed women had at le ast one ectopic pregnancy more often than unexposed women (RR 3.84, CI 2.26 , 6.54). Conclusion: Pregnancy outcomes in DES-exposed women were worse than those i n unexposed women. (Obstet Gynecol 2000;96:483-9. (C) 2000 by The American College of Obstetricians and Gynecologists.).