Umbilical cord cysts in the second and third trimesters: significance and prenatal approach.

Objectives: This study was carried out to determine the prognosis, and the clinical approach, in fetuses with umbilical cord cysts, during the second and third trimesters of gestation, according to our experience and data in the current literature.

Methods: We identified 10 fetuses with umbilical cord cysts that were diagnosed during the second and third trimesters of pregnancy at three referral centers. All underwent detailed ultrasound evaluation at the time of diagnosis and during follow-up. Prenatal karyotype testing was offered to all women. A MEDLINE review of the literature published from 1980 to 2009 was carried out to identify previous studies and case reports of fetuses with umbilical cord cysts.

Results: In our series of 10 cases, significant additional abnormalities were observed in two during a detailed sonogram. In one case, trisomy 18 was diagnosed, leading to pregnancy termination, and in the other case a neonate with heart defects and a normal karyotype was born. These results differ from those reported in the literature, in which the association between second- and third-trimester umbilical cord cysts and fetal anomalies ranged from 38 to 100%.

Conclusions: In our study, as in other publications, an association was found between the presence of second- and third-trimester umbilical cord cysts and fetal anomalies. The strong association between second- and third-trimester umbilical cord cysts and aneuploidy in the literature seems to be biased, mainly because of the tendency to report abnormal cases. When these findings are accompanied by additional sonographic abnormalities, the association with aneuploidy is clear and should be an indication for fetal karyotype testing.