Prenatal Diagnosis of Umbilical Artery Aneurysm A Potentially Lethal Anomaly

Aneurysm of the umbilical artery has only rarely been diagnosed prenatally. Of the 4 cases reported in the literature, 3 had trisomy 18 with its classic sonographic stigmata. 1 In all 3 cases, the aneurysm was close to the placental insertion of the cord. In the previously reported case with an isolated umbilical artery aneurysm, there was a single umbilical artery, and the fetus died in utero at 35 weeks despite intensive fetal monitoring.