Polycystic ovary syndrome and risk of uterine leiomyomata.

OBJECTIVE: To examine the association between polycystic ovary syndrome (PCOS) and the risk of uterine leiomyomata (UL).
DESIGN: Prospective cohort study.
SETTING: Participants from the Black Women's Health Study, an ongoing prospective cohort study of African-American women aged 21-69 years in 1995 residing in the United States. Participants completed mailed questionnaires about their health status every 2 years. PATIENT(S): Premenopausal women with no history of UL at the start of follow-up (N = 23,571). INTERVENTION(S): No interventions were administered. MAIN OUTCOME MEASURE: Incidence of UL among those with and without self-reported, physician-diagnosed PCOS over a 6-year period of follow-up (1997-2003). Medical-record validation in a random subset of UL cases confirmed 96% of diagnoses. RESULT(S): During 114,373 person-years of follow-up, 3,631 new cases of UL confirmed by ultrasound (N = 2,926) or hysterectomy (N = 705) were reported. After adjustment for potential confounders, the incidence of UL was 65% higher among women with PCOS than women without PCOS (incidence rate ratio, 1.65; 95% confidence interval, 1.21-2.24). The incidence rate ratios remained constant with increasing time after the diagnosis of PCOS. Results were similar when analyses were confined to women reporting a recent Papanicolaou smear, a proxy for a pelvic examination. CONCLUSION(S): The present study suggests a positive association between PCOS and UL in African-American women.