Developmental anomaly with a single umbilical artery in the umbilical cord occurs very rarely. In this work the author has attempted to find this anomaly in normal full-term pregnancies, on the ground of corrosion casts of fetal appendages. Placentas with umbilical cords and fetal membranes were taken from normal pregnancies, where neonates were healthy, and their birth weight was normal. It was established, that this variety was present in two organs among 53 placentas (3.8% of cases).

Keywords: single umbilical artery, Umbilical Cord, normal full-term pregnancy