Maternal adnexal masses in pregnancy

Maternal adnexal masses are increasingly detected during pregnancy, primarily due to the widespread use of ultrasound in obstetrics. Most of them are functional cysts that resolve spontaneously. Lesions visualized by ultrasound in adnexal topography may be retroperitoneal or intraperitoneal (non-gynecologic or obstetric/gynecologic formations, such as pregnancy-related masses, subserosal uterine fibroids or true adnexal lesions). The largest number of adnexal lesions do not change their ultrasound morphology in pregnancy. However, endometriomas may decidualize, mimicking borderline or stage I invasive ovarian malignancies. The patient management can be conservative (ultrasound surveillance) or surgery. The decision depends on a series of factors including the risk of malignancy. Until mathematical models have been widely validated in pregnancy, the International Ovarian Tumor Analysis Group recommends using simple benign descriptors and expert subjective assessment to predict the risk of maternal adnexal malignancy in pregnancy. In the future, artificial intelligence could be useful.