Transvaginal sonographic ovarian findings in a random sample of women 25-40 years old

Objective To investigate the occurrence rate of adnexal lesions in premenopausal women. Methods A random sample of women 25-40 years old was invited to undergo a transvaginal ultrasound examination, and 335 women were examined. The criteria used to define an adnexal lesion were either a cystic lesion with its largest diameter of at least 25 mm within the pelvic region, or the appearance of solid parts in any lesion regardless of size. Results Adnexal lesions were found in 26/335 cases, (7.8%) (95% confidence interval (CI), +/-2.9%). The occurrence rate of ovarian cysts was 22/335 (6.6%) (95% CI, +/- 2/7%). There were no differences between the women with or without ovarian cysts related to age, smoking habits, parity or body mass index. At follow-up 3 months later, 18 of the 22 (82%) cysts had disappeared (95% CI, +/-16%). Women using progesterone contraception (either oral contraception or an intrauterine device with levonorgestrel) had a significantly higher relative risk of 2.7 (95% CI, 1.1-6.9) of functional cysts as compared to women with natural cycles. Polycystic ovaries were found in 10.2% (95% CI, +/-4.2%) of the women not using any hormonal contraception. The mean volumes of the polycystic ovaries were significantly larger compared to those in natural cycles. Conclusion Adnexal lesions are common in asymptomatic women in the age group 25-40 years, but four out of five ovarian cysts disappeared spontaneously after 3 months. The ultrasound appearance of the cyst, the woman's family history and her own feelings must be considered if a persisting cyst is to be surgically removed or followed by repeated transvaginal ultrasound.