Naturally occurring anti-Rh antibody.

ALTHOUGH anti-A and anti-B occur normally in all persons of blood Type O, anti-Rh (anti-D) is not normally found even in Rh-negative persons, unless they have had specific stimulation in the form of blood transfusion or incompatible fetus. Only 1 previous case has been reported§ in which the presence of anti-Rh was believed unaccountable on the basis of either transfusion or pregnancy. Case Report Mrs. X, a 24-year-old Type O, Rh-negative woman, was pregnant for the 1st time. At 36 weeks' gestation, the blood was found to contain anti-Rh antibodies in low titer (1:2). Her husband was Rh negative, and . . .