Ovulation suppression for endometriosis for women with subfertility

Background Endometriosis is the presence of endometrial glands or stroma in sites other than the uterine cavity and appears to be an oestrogen-dependent condition. This dependency has prompted the therapeutic use of ovulation suppression agents in an effort to improve subsequent fertility. Objectives To assess the effectiveness of ovulation suppression agents, including danazol, progestins and oral contraceptives, in the treatment of endometriosis-associated subfertility in improving pregnancy outcomes including live births. Search methods We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register of trials (February 2009), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2009), MEDLINE (1966 to February 2009), EMBASE (1980 to February 2009), and reference lists of articles. Selection criteria Randomised trials comparing an ovulation suppression agent with placebo or no treatment, a suppressive agent with danazol, or a gonadotropin-releasing hormone analogue (GnRHa) with oral contraception in women with endometriosis. Data collection and analysis Two review authors independently extracted data and assessed quality. We contacted study authors for additional information. Main results Twenty-five trials were included. Only two studies reported live births. The odds ratios (OR) for pregnancy following ovulation suppression versus placebo or no treatment was 0.97 (95% confidence interval (CI) 0.68 to 1.34, P = 0.8) for all women randomised, and 1.02 (95% CI 0.70 to 1.52, P = 0.82) for subfertile couples only despite the use of a variety of suppression agents. There was no evidence of benefit from the treatment. The common OR for pregnancy following all agents versus danazol was 1.38 (95% CI 1.05 to 1.82, P = 0.02) for all women randomised, and 1.37 (95% CI 0.94 to 1.99, P = 0.10) for subfertile couples only. When GnRHa and danazol were directly compared, the OR was 1.45 (95% CI 1.08 to 1.95, P = 0.01) for all women randomised, and 1.63 (95% CI 1.12 to 2.37, P = 0.01) for subfertile couples only, in favour of GnRHa. No effect was observed for GnRHa compared with oral contraception (OR 0.93, 95% CI 0.41 to 2.12, P = 0.86 for all women randomised; OR 0.83, 95% CI 0.34 to 2.05, P = 0.69 for subfertile couples only). Authors' conclusions There is no evidence of benefit in the use of ovulation suppression in subfertile women with endometriosis who wish to conceive.