1. Two-vessel Cord - normally, umbilical cord contains two arteries and one vein (AVA). Absence of one vessel is said to be associated with congenital heart disease and kidney anomalies because they arise from one germ layer - mesoderm.
2. Unusual Cord Length - an unusually short umbilical cord can cause abruptio placenta or an abnormal fetal lie. On the other hand, when the cord is unusually long, the cord can be compressed too easily.