Fetal-maternal macrotransfusion--a study of 400 postpartum women.

The results of postpartum fetal cell counting in 400 Rh-negative patients delivering Rh-positive infants are presented and correlated with the mode of delivery and the ABO blood group relationship of baby and mother. Manipulative procedures, especially Caesarean section, are shown to increase the incidence of macrotransfusion. To make the most economical use of the new 125 microgram doses of anti-D gamma globulin, quantitation of fetal-maternal transfusions is shown to be vital if the existing level of protection from rhesus sensitization is to be maintained or increased.