Ovarian cysts in pregnancy: does ultrasound make traditional management inappropriate?

In a retrospective series of 131 ovarian tumors associated with pregnancy, 81 (including one carcinoma and six tumors of borderline malignancy) were removed. Eighty-three cysts were examined by ultrasound. All 15 of less than 5 cm in diameter resolved spontaneously. Of 68 larger than 5 cm in diameter, 39 had a simple internal echo pattern and a smooth wall; 19 of these disappeared, and the histology of seven others suggested they might have resolved if treated conservatively. Three of the tumors of borderline malignancy also showed a simple ultrasound pattern, but higher-resolution machines may have differentiated two of these. We suggest a policy of selective conservative management of ovarian cysts during pregnancy on the basis of the ultrasound appearance.