Are oral contraceptives an effective therapy for ovarian cysts?
Oral contraceptives are not an effective treatment for ovarian cysts, whether the cysts are spontaneous or associated with medically induced ovulation. Most cysts resolve without intervention within two to three months. Those that do not resolve in this time frame are more likely to be pathologic in nature and should prompt referral for a surgical evaluation. (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)
Oral contraceptives have long been known to be highly effective at suppressing the development of ovarian cysts. In one study, the relative risk of developing ovarian cysts was 0.22 (95% confidence interval, 0.13 to 0.39) for women taking an oral contraceptive compared with those not taking an oral contraceptive.1 Although oral contraceptives are commonly used to treat ovarian cysts, the authors sought to clarify whether this is appropriate. Eight randomized controlled trials were included in this review. Although the studies were too heterogeneous to conduct meta-analyses for most questions, results from these studies were consistent enough to draw several conclusions.
Five trials looked at spontaneously occurring ovarian cysts, representing a combined total of 398 women. The largest study included 141 women, and four of the studies were conducted in Turkey. The oral contraceptives used in these studies contained ethinyl estradiol combined with desogestrel or levonorgestrel. Individually, none of the five trials found a statistically significant benefit of oral contraceptive use vs. expectant management in expediting resolution of cysts.
Three trials with a total of 288 participants evaluated the effectiveness of oral contraceptives for treating ovarian cysts in women whose ovulation was medically induced. In these studies, ovulation was induced with clomiphene (Clomid), human menopausal gonadotropin, human chorionic gonadotropin, or a combination of these medications. Eligibility criteria for these studies included the presence of an adnexal cyst that was at least 1.5 to 2 cm in diameter. Participants were randomized to monophasic oral contraceptives or expectant management. Problems with randomization, blinding, and sample size estimation were common to all three studies. No benefit of oral contraceptives over expectant management was observed in any trial.
A common finding in the studies included in this review was that ovarian cysts that were not resolving within two to three cycles were often pathologic in nature. For example, in a 2003 study of 62 women randomized to oral contraceptives or expectant management, 19 women had persistent cysts and subsequently underwent laparoscopy.2 Six of the cysts were serous cystadenomas, four were endometriomas, two were mucinous cystadenomas, and one was a mucinous cystadenofibroma. The remaining six were follicular cysts. This reflects the general consensus that functional cysts typically resolve in eight to 12 weeks.3 These findings are also consistent with current guideline recommendations that ovarian cysts smaller than 50 mm be managed expectantly for up to three cycles and that oral contraceptives not be used for treatment.4