Fetal Cell Counting as an Evaluation of Rh Prophylaxis with Antenatally Administered Anti‐RhO (D) Gamma Globulin

Abstract

Fetal cell counts were performed on pregnant women at 34 wk gestation following an injection of Anti-Rho (D) .gamma.-globulin at 28 wk gestation. In cases where the fetus was Rho (D) positive and ABO compatible, the fetal cell detection rate and the mean number detected were considerably less than those where the fetus was Rh negative. Postpartum fetal cell counts after 1 and 2 antenatal anti-Rho (D) .gamma.-globulin injections were also less when the baby was Rh positive than when the baby was Rh negative. Antigen clearance is probably part of the mechanism involved in Rh prophylaxis by the use of anti-Rho (D) .gamma.-globulin.