AbstractA malformed human fetus with multiple congenital anomalies including absence of an umbilical artery is described. These anomalies include malpositioning of the apex of the heart; a “mirror image” position of the liver; mal‐rotation of the gut with absence of external demarcation into small and large intestine; failure of development of the cloacal region with imperforate anus and absence of a urethra; undescended testes and bilaterally mal‐placed scrotal sacs, but the presence of a median phallus in spite of the failure of the ventral abdominal wall to develop fully.Factors known to influence the production of fetal anomalies in man and animals are discussed and a brief review of the literature on single umbilical arteries, which are known to be associated frequently with congenital anomalies, i