Fetal Erythrocytes in Maternal Circulation After Spontaneous Abortion

Abstract

Transplacental passage of fetal erythrocytes occurs in 32% of patients undergoing spontaneous abortion. Intrauterine instrumentation for incomplete abortion favors the placental passage of larger volumes of fetal cells. The relationship of isoimmunization to transplacental hemorrhage, although clearly established in term pregnancies, remains to be elucidated after abortion. Because of the unknown risk of sensitization from this cause, and since 26% of our patients show evidence of transplacental hemorrhage of 0.05 ml or more, the practice of administering anti-Rho γ-globulin after abortion in an Rh-negative patient seems indicated. We suggest that early isoimmunization, and thus apparent subsequent failures in Rh prophylaxis, may be caused by a large fetal hemorrhage which occurs during pregnancy after threatened abortion.