Prenatal diethylstilbestrol (DES) exposure is associated with uterine leiomyoma development

Early life exposure to DES causes uterine leiomyomata in laboratory animals. We examined the relationship between prenatal DES exposure and development of uterine leiomyomata in women. Among randomly selected study participants (819 black women, 504 white women), leiomyoma status was determined by ultrasound screening (70%) or surgical record review (7%). We relied on self-report of prior diagnosis in 13%. Leiomyoma status could not be ascertained for 10% and they were excluded from analyses. Prenatal DES exposure was assessed by interview. All five of the black women who reported DES exposure had leiomyomata. Among white women, 76% who reported prenatal DES exposure had leiomyomata compared with 52% of the unexposed (adjusted odds ratio for whites: 2.4; 95% confidence interval CI: 1.1-5.4). Exposed women tended to have larger tumors. Results were robust to sensitivity analyses. Findings support experimental animal data and indicate a role for prenatal estrogen exposure in the etiology of human uterine leiomyoma.