Maternal-fetal hemorrhage: its incidence and sensitizing effects.

Although anti-Rh-immune globulin is highly effective in preventing hemolytic diseases of the newborn, there are some failures. The causes for these failures often are unknown and it has been postulated that some of them are caused by the transfer of maternal Rh-positive red cells into the Rh-negative infant at the time of birth. A study of 107 Rh-negative newborn infants born of Rh-positive mothers has demonstrated that maternal-fetal hemorrhage is rare (approximately 2 per cent) and that Rh antibody produced during the first six months in Rh-negative babies is similarly rare. Routine administration of anti-Rh gamma globulin to Rh-negative neonates is not indicated.