Objective: To analyse the association between oral contraceptive use and the risk of uterine fibroids.
Design: We considered data collected in a case-control study on risk factors for uterine fibroids.
Participants: We studied 843 women with uterine fibroids, whose clinical diagnosis dated back no more than two years. Controls were 1557 non-hysterectomised patients younger than 55 years admitted for acute, non-gynecological, non-hormonal, non-neoplastic conditions.
Results: A total of 254 cases (30.1%) and 360 controls (23.1%) reported ever using oral contraceptives: the odds ratio (OR) for ever vs never users was 1.1 (95% CI 0.8-1.3). The risk in current users was below unity when compared with never users (OR 0.3, 95% CI 0.2-0.6), while ex-users had a risk of fibroids comparable with never users (OR 1.1, 95% CI 0.9-1.4). The risk of uterine fibroids decreased with duration of oral contraceptive use: compared with never users, the estimated OR was 0.8 (95% CI 0.5-1.2) in ever users for four to six years and 0.5 (95% CI 0.3-0.9) for seven years or more (chi2 trend = 4.6, P = 0.03).
Conclusions: Although the role of selection bias should be carefully evaluated, the present data suggest that uterine fibroids should not be considered a contra-indication for oral contraceptive use.
PIP: A study was conducted to analyze the association between oral contraceptive (OC) use and risk of uterine fibroids. Subjects of the study included 843 women whose clinical diagnosis of uterine fibroids dated back no more than 2 years prior to the study. Use of OCs was found in 30.1% of subjects and 23.1% of controls. The frequency of uterine fibroids was lower in current OC users and inversely related to duration of use. No association emerged between fibroid risk and OC use. No apparent pattern of risk emerged with time since first or last OC use. The findings indicate that uterine fibroids should not be considered a contraindication for OC use.