Malformations and chromosome anomalies in spontaneously aborted fetuses with single umbilical artery.

Presence of a single umbilical artery was noted 13 times among a series of 879 consecutively collected, spontaneously aborted embryos and fetuses. This rate of 1.5% is approximately twice that reported from the largest series of term births. Eight of the 13 fetuses had additional serious malformations. Of nine successfully karyotyped fetuses, six had chromosome anomalies. All six occurred in fetuses with severe malformations in addition to the single umbilical artery. The presence of single umbilical artery with other major anatomic defects may be a significant predictor of the presence of chromosome anomalies in live births. Early recognition of offspring with chromosome anomalies will be useful in counseling the family and in managing the care of the infant.