Fetal ovarian cysts: prenatal diagnosis, management and postnatal outcome.

OBJECTIVE: In female fetuses ovarian cysts represent the most important differential diagnosis for intra-abdominal masses. Analyzing our own patient population we investigated whether there was a connection between sonographic parameters and postnatal course, especially with regard to the need for surgical intervention.

PATIENTS AND METHODS: This was a retrospective analysis of cases from the years 1986-1999. The pre- and postnatal data of 64 fetuses who were suspected prenatally to have an ovarian cyst were analyzed. The postnatal outcome was known for all the children.

RESULTS: The diagnosis was made in all cases in the third trimester (median, 35; range, 26-40 weeks' gestation). In 34 of the 64 (53%) cases, resolution of the cyst occurred either prenatally (n = 18, 53%) or postnatally (n = 16, 47%). The cystic structure in the cases with resolution was isolated, smooth-walled (n = 29) or heterogeneous (n = 5). Postnatal surgery was performed in 30 of the 64 (47%) children. In 18 of the 30 children a fenestration of the ovary was performed (60%). In this group there were 13 children with an isolated, smooth-walled ovarian cyst and five children with a heterogeneous cyst. Twelve of the 30 (40%) children underwent an ovariectomy. Among these 12 children there were eight cases with a heterogeneous cystic structure and four cases with an isolated, smooth-walled cystic structure. Of the 30 cases that underwent surgery, 29 had a follicular cyst and one had an ovarian teratoma (with a heterogeneous internal structure). In three fetuses aspiration of cyst fluid was undertaken and subsequent resolution occurred in one case. The other two cases had to undergo postnatal fenestration.

CONCLUSIONS: When an ovarian cyst is suspected prenatally, serial ultrasound monitoring should follow and delivery should take place in a perinatal center. The prenatal findings should also be checked postnatally by ultrasound. Prenatal aspiration of the cyst seems to be of no advantage and should be carried out only in special individual cases.