Endometriosis in pregnancy - diagnostics and management.

OBJECTIVE: Endometriosis in pregnancy predominantly tends to regress or to stay stable but small part of endometriomas and nodules of deep infiltrating endometriosis may undergo the process of decidualization. Therefore, the foci of endometriosis enlarge their volume and change their structure due to cellular hypertrophy and stromal edema associated with higher vascularization caused by the hormonal changes in pregnant women. Consequently, these totally benign lesions may resemble malignant tumors in ultrasound examination. DESIGN: Review article. SETTING: Department of Obstetrics and Gynecology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague. METHODS: A literature review of published data on decidualization of endometriosis. RESULTS: Majority of decidualized ovarian endometriomas is asymptomatic so it is mostly accidentally found during the routine ultrasound check-ups within the frame of perinatologic screening. The rounded, smooth, highly vascularized solid papillary projections in internal wall of endometroid cysts are the most specific characteristics of decidualization. If ultrasound simple rules are not applicable or show probable malignancy, the pregnant patient should be referred to a tertiary center for expert ultrasound assessment. Magnetic resonance is indicated in cases of uncertain ultrasound findings, because it can clarify the diagnostics due to its high accuracy in detection of products of blood degradation and ability of diffusion-weighted imaging to recognize lower tissue cellularity of benign decidualized endometriomas in comparison to malignant ovarian tumors. CONCLUSION: If the imaging methods confirm supposed decidualized endometriosis, watch and wait management based on regular ultrasound examinations during the whole pregnancy and after childbed is recommended. The regression of the tumor size and disappearance of the solid portions within endometriomas is expected after delivery. Decidualized endometriosis is rarely a source of gestational or obstetrical complications demanding acute surgical intervention. Elective surgical procedures in pregnant women are indicated only if expert ultrasound or magnetic resonance imaging assess the masses as border-line or invasive tumors (carcinomas) and in cases of suspicious changes of the originally presumed benign cysts during the surveillance.