Prenatal Diethylstilbestrol Exposure and Risk of Uterine Leiomyomata

First-trimester DES exposure may be associated with an increased risk of uterine leiomyomata

image of Uterine Leiomyomata
These 2013 results suggest that first-trimester DES exposure may be associated with an increased risk of uterine leiomyomata. The association was highest for women exposed to DES in the first trimester, which corresponds to early stages of fetal mullerian development. Image by Nephron via Wikimedia Commons.

2013 Study Abstract

Previous studies evaluating the association of prenatal exposure to diethylstilbestrol (DES), a potent endocrine disruptor, with incidence of uterine leiomyomata (UL) have had conflicting results. We evaluated the association between prenatal DES exposure and incident UL in women in the Nurses’ Health Study II from 1989 to 2009. Women were aged 25–42 years at enrollment and had a prenatal exposure window corresponding to DES use. The analytical sample was larger than previous studies and included 102,164 premenopausal women with intact uteri, no prior history of UL or cancer, and prenatal DES exposure. Multivariable-adjusted Cox proportional hazard models were used to estimate the relationship between DES exposure and UL risk. During 1,273,342 person-years of follow-up, there were 11,831 incident cases of UL. Women with prenatal exposure to DES had a higher incidence of UL compared with unexposed women, with an adjusted hazard ratio of 1.12 (95% confidence interval: 0.98, 1.27). Risk was strongest for women exposed to DES in the first trimester, when exposure corresponds to early stages of fetal Müllerian development (adjusted hazard ratio = 1.21, 95% confidence interval: 1.02, 1.43). These results suggest that first-trimester DES exposure may be associated with an increased risk of UL, but they must be interpreted with concern for detection and recall biases.

2013 Study Conclusions

We found a small positive association between DES exposure and risk of UL. Among women reporting trimester of DES initiation, the association was strongest when DES was initiated in the first trimester. These results should be interpreted with caution because of the possibility of recall bias in both participants and their mothers, as well as detection bias due to increased gynecological surveillance in exposed women. Because DES-exposed women are aging out of leiomyomata research, the possibility for future study of this association is limited. However, studies of DES exposure and outcomes of concern may provide a framework for other similarly acting estrogenic endocrine disruptors, such as Bisphenol A and dioxin.

Sources and Full Study
  • Prenatal Diethylstilbestrol Exposure and Risk of Uterine Leiomyomata in the Nurses’ Health Study II, Oxford Journals, American Journal of Epidemiology, doi: 10.1093/aje/kwt250, 179 (2): 186-191, October 18, 2013.
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