Pediatricians, although caring for newly born infants, often have limited knowledge of abnormalities of the placenta that may affect the infant. Few articles on this subject appear in pediatric journals. Pediatricians gain relevant personal experience indirectly, and in fact, seldom see even grossly abnormal placentas. Until recently, the treatment of most distressed newly born infants has been supportive and nonspecific; consequently, study of obstetrical events has not appeared important in the medical management of the infant. The purpose of this article is to encourage pediatricians to evaluate the effect of placental abnormalities on newborn infants. Gross structural or mechanical abnormalities of the cord and placenta will be emphasized. Little is known about abnormal placental function and its effect on the fetus. Abnormalities of placental implantation, such as circumvallate placenta associated with midterm abortion or placenta accreta causing incomplete placental separation after delivery of the infant, are not included because of