Women of reproductive age usually release an egg about once a month. The ovary gets an egg from the inside of the ovary to its surface by creating a blister or fluid-filled space around the developing egg. When the blister (or cyst) reaches the surface of the ovary, it bursts and releases the egg into the abdominal cavity. After this occurs, the blister can develop into another type of cyst, which makes a hormone (progesterone) that helps the pregnancy to grow. Most of these cysts come and go without problems. Sometimes, however, the cysts get large or painful; others may remain for months. Several decades ago, health care providers learned that women taking birth control pills had fewer cysts, since the pills usually kept an egg from being released. Based on this fact, many clinicians started treating these cysts with birth control pills to make them go away faster.
In March 2014, we did a computer search for all randomized controlled trials that studied use of birth control pills to treat these benign (also called functional) cysts. We wrote to researchers to find other trials. We found eight trials from four countries; they included 686 women. Three trials included women receiving drugs to help them get pregnant. The other five included women who developed cysts without fertility treatment. In none of these trials did oral contraceptives help the cysts go away faster. Thus, birth control pills should not be used for this purpose. A better approach is waiting two or three months for the cysts to go away on their own.
Although widely used for treating functional ovarian cysts, combined oral contraceptives appear to be of no benefit. Watchful waiting for two or three cycles is appropriate. Should cysts persist, surgical management is often indicated.
Functional ovarian cysts are a common gynecological problem among women of reproductive age worldwide. When large, persistent, or painful, these cysts may require operations, sometimes resulting in removal of the ovary. Since early oral contraceptives were associated with a reduced incidence of functional ovarian cysts, many clinicians inferred that birth control pills could be used to treat cysts as well. This became a common clinical practice in the early 1970s.
This review examined all randomized controlled trials that studied oral contraceptives as therapy for functional ovarian cysts.
In March 2014, we searched the databases of CENTRAL, PubMed, EMBASE, and POPLINE, as well as clinical trials databases (ClinicalTrials.gov and ICTRP). We also examined the reference lists of articles. For the initial review, we wrote to authors of identified trials to seek articles we had missed.
We included randomized controlled trials in any language that included oral contraceptives used for treatment and not prevention of functional ovarian cysts. Criteria for diagnosis of cysts were those used by authors of trials.
Two authors independently abstracted data from the articles. One entered the data into RevMan and a second verified accuracy of data entry. For dichotomous outcomes, we computed the Mantel-Haenszel odds ratio with 95% confidence interval (CI). For continuous outcomes, we calculated the mean difference with 95% CI.
We identified eight randomized controlled trials from four countries; the studies included a total of 686 women. Treatment with combined oral contraceptives did not hasten resolution of functional ovarian cysts in any trial. This held true for cysts that occurred spontaneously as well as those that developed after ovulation induction. Most cysts resolved without treatment within a few cycles; persistent cysts tended to be pathological (e.g., endometrioma or para-ovarian cyst) and not physiological.