PRENATAL-DIAGNOSIS OF OMPHALOCELE ASSOCIATED WITH UMBILICAL-CORD CYST

Background. To study the cytogenetics, ultrasound findings, biochemica l screening, perinatal outcome, and associated abnormalities in cases of omphaloceles associated with umbilical cord cysts. Methods. From 19 88 to 1994, three cases of omphaloceles with umbilical cord cysts were identified at Mackay Memorial Hospital. We compared the clinical data of our three cases with six other cases in the published literature. Results. Two cases of omphaloceles with umbilical cord cysts were affe cted with trisomy 18. One had bilateral choroid plexus cyst, intrauter ine growth retardation, low levels of maternal serum alpha-fetoprotein and free beta-human chorionic gonadotropin, and the other had cleft l ip and palate, single umbilical artery and intrauterine growth retarda tion, An elevated level of maternal serum alpha-fetoprotein was found in the case with normal karyotype. Elevated levels of amniotic fluid a lpha-fetoprotein were found in two cases. Rupture of the umbilical cor d cyst and disruption of the umbilical cord occurred in one case at de livery. Based on the gross and microscopic examinations, the cord cyst s we observed are likely to be pseudocysts. Conclusion. The umbilical cord cysts most commonly associated with omphaloceles are pseudocysts and allantoic cysts. Among our three cases and the six other cases pub lished in the literature, four out of these nine cases were trisomy 18 . Prenatal diagnosis of omphaloceles or umbilical cord cysts by ultras ound warrants cytogenetic analysis and detailed sonogram to rule out t he possible combination of both abnormalities and trisomy 18. If an om phalocele is associated with a large umbilical cord cyst and a normal karyotype, cesarean section is recommended to prevent the dilemma of i ntrauterine vascular compromise of umbilical blood flow during labor.