Uterine leiomyoma and menstrual cycle characteristics in a population-based cohort study

Background: We examined the association of uterine leiomyoma with menstrual cycle characteristics in a population of non-care-seeking women. Methods: This cross-sectional study uses data from the Seveso Women's Health Study (SWHS), a population-based cohort in Italy. Participants included 341 premenopausal women, 30-60 years old, who had an intact uterus and were not pregnant, lactating, or using oral contraception or intrauterine devices. We examined the presence of any ultrasound-detected uterine leiomyoma in relation to self-reported menstrual cycle length, flow length and heaviness of flow. The association of leiomyoma number, volume, tissue layer location and axial position with menstrual cycle characteristics was also examined. Results: Uterine leiomyomata were detected in 73 women (21.4%). After adjustment for covariates, the presence of a leiomyoma was not significantly related to menstrual cycle length, flow length or heaviness of flow [odds ratio (OR) for scanty flow = 1.9, 95% confidence interval (CI) 0.8-4.3; OR for heavy flow = 1.3, 95% CI 0.7-2.5; relative to moderate flow]. Number, volume, tissue layer location (subserosal or intramural) and axial position (anterior or posterior) of the leiomyoma were also not related to menstrual cycle characteristics. Conclusion: In this Italian population of women not seeking gynaecological care, menstrual characteristics are not related to leiomyoma.