The Absence of One Umbilical Artery in Malformed MZ Twins

Abstract

SummaryThe authors studied the structure of the umbilical cord in a cephalothoracopagus and a holoacardius amorphus. In both cases they met with the absence of one umbilical artery. They discuss on the possible teratogenic influence of this umbilical anomaly, which appears in the acardius as a regular phenomenon, and, along with the velamentous insertion and with the vascular anastomoses bringing about the reverse blood circulation, constitutes the main cause of malformation.