Functional ovarian cysts in premenopausal and gynecologically healthy women.

The present study describes 29 women coincidentally found to have ovarian cysts while participating in a cross-sectional study. The prevalence of functional ovarian cysts is determined. In this study, 428 women, aged 14-45 years, were examined by transvaginal ultrasonography. The women were gynecologically healthy and were using either no contraception, intrauterine contraceptive devices, none of which were hormone releasing, or oral contraception (OC). Cysts were defined as cystic spaces larger than 30 mm. All women were asymptomatic and regularly menstruating.The prevalence of ovarian cysts was lower for women using OC than for women using no contraception or using intrauterine contraceptive devices. The relative risk (measured as the prevalence proportion ratio) of having an ovarian cyst when using OC was 0.22 (CI: 0.13-0.39), compared to women not using OC. No difference was found in the prevalence of ovarian cysts between women using intrauterine contraceptive devices and women using no contraception. The prevalence of ovarian cyst increased throughout the menstrual cycle in women not using OC. This relation was not found in the group of users of OC. The majority of the cysts resolved within the first few days of menstruation. Sixty-five percent of the cysts persisting after menstruation had resolved at the first control examination 3 months later, independently of use of OC. Low-dose monophasic contraceptive pills seem to have a protective effect against development of functional ovarian cysts, independent of the type of gestagen and the dose of ethinylestradiol used. Ovarian cysts resolved independently of treatment with OC. The use of intrauterine contraceptive device had no influence on the occurrence of functional ovarian cysts.