Uterine fibroids risk and history of selected medical conditions linked with female hormones.

To understand the role of several medical conditions on the risk of uterine fibroids, we analysed the findings of a large case-control study. Cases were 843 women aged 54 or less (median age 43 years, range 21-54) with histologically confirmed uterine fibroids, whose clinical diagnosis dated back no more than 2 years. Indications for surgery were recurrent menorrhagia or ultrasound evidence of fibroids larger than 10 cm in diameter. Controls were 1557 women aged 54 years or less of comparable quinquennia of age (median age 43 years, range 21-54) who had not undergone hysterectomy and were admitted for acute, non-gynecologic, non-hormonal, non-neoplastic conditions to a network of hospitals with a similar catchment area. Clinical history of severe overweight was inversely associated with the risk of fibroids (multivariate odds ratio (OR), OR: 0.6, 95% confidence intervals (CI): 0.5-0.8). An increase in the frequency of fibroids was seen in women with a history of benign breast disease (OR: 1.2, 95% CI: 0.9-1.6) and particularly of breast biopsies (OR: 2.0, 95% CI: 1.2-3.5). The results of this large dataset indicate that medical conditions known or likely to be related to female hormones are not important determinants of the risk of fibroids.