Advancements in sonographic technology have led to improved prenatal detection of fetal anomalies. Umbilical cord cystic masses are being detected prenatally and several case reports have appeared in the literature. We report three new cases in which umbilical cord cystic masses were detected prenatally; two cases in the later half of pregnancy and one case in the first trimester. The literature was reviewed and summaries of the 23 reported cases of persistent second- and third-trimester umbilical cord cystic masses and their implications are discussed. There is a high association (18 of 23 cases) with lethal chromosomal anomalies and/or congenital malformations suggesting that the finding of an isolated umbilical cord cystic mass should lead to further detailed sonographic evaluation.