IV. Antenatal prophylaxis in the prevention of Rh hemolytic disease of the fetus and newborn (HDN)

Gac Méd Méx Vol. 140, Suplemento No. 3, 2004 Rh haemolytic disease of the fetus and newborn (HDN) is a condition in which the lifespan of the infant’s red cells is shortened by the binding of specific IgG Rh antibodies produced by the mother, which transfer across the placenta. The disease begins in intra-uterine life and shows a wide spectrum of severity. Not all D-positive infants born to mothers with anti-D are affected by HDN. Some infants are only mildly affected and the hemolytic process is most severe after birth; however, jaundice and anemia become more severe at birth. More severely affected infants, if not treated with exchange transfusion, develop profound hyperbilirubinaemia which impregnates the basal ganglia causing kernicterus with signs of brain damage leading to death within a week of birth in 70% of cases; those who survive have permanent brain damage characterized by choreoathetosis and spasticity and, in milder cases, by high-frequency deafness. The most severe manifestation of HDN is profound anaemia, developing in utero as early as the 18th week of gestation and leading to hydrops fetalis with generalized edema, ascites, hepatosplenomegaly, erythroblastosis and a high mortality.