Ovarian endometriosis during pregnancy: a series of 53 endometriomas

The sonographic features of endometriomas and their natural history during pregnancy remain poorly known. The objective of our study was to report our experience concerning the diagnosis, spontaneous progression and management of endometriomas during pregnancy.

A retrospective observational study in 46 patients (53 cysts) presenting with an ovarian endometrioma diagnosed during ultrasound examination at the first trimester of pregnancy. Sonographic findings (according to the criteria of the International Ovarian Tumor Analysis (IOTA) group and how they changed for each cyst during pregnancy and postpartum were reviewed, together with cyst management. The median follow-up was 4 years [IQR: 3-6]. Median age at diagnosis was 31 years [IQR: 27-35].

Among the 53 cysts identified as "endometriomas" on the first-trimester ultrasound examination, 49 (92%) were described like "cyst fluid with ground-glass echogenicity". Fifty-two cysts (98%) had a maximum diameter<100mm, only one cyst (2%) presented papillary projection and 5 cysts (9%) were multiloculated. During the second-trimester ultrasound monitoring of these cysts, of the 33 cysts that we monitored, 8 (24%) increased in size, 11 (34%) decreased in size, 5 (15%) disappeared and 9 (27%) did not change. During the third-trimester ultrasound monitoring of these cysts, of the 13 cysts that we monitored, 5 (39%) increased in size, 5 (39%) decreased in size, 2 (15%) disappeared and 1 (7%) did not change. All children (48 newborns) were born alive at a median gestational age of 39 weeks [IQR=39-40]. Only 10 cysts (19%) required surgical treatment. In all cases, surgery consisted of cystectomy. Two cysts were operated on during pregnancy (between 14 and 17 weeks of gestation) because of symptoms of adnexal torsion, 3 during cesarean section, and 5 postpartum. Four of the 10 (40%) cysts operated on were histopathologically "endometriomas", and one of them was decidualized. Four cysts were mucinous cystadenomas, one was a serous cystadenoma and one cyst was a dermoid cyst.

This study underscores the difficulty of diagnosing endometriomas during pregnancy and the absolute necessity of surgical removal when ultrasonographic findings are doubtful.