Rhogam administration is indicated in Rh negative blood types patients with Rh positive fetuses in order to prevent alloimunization. In general is contraproductive to determine fetal blood type and the partner is taken as reference. Should the administration be missed, the mother becomes sensitized to Rh positive antigens. Although the current pregnancy continues unaffected all the future pregnancies with Rh positive blood types fetuses may have a catastrophic outcome. Maternal antibodies enter fetal circulation destroying red blood cells and causing sever anemia that can be fatal to the baby. Although there are means to determine the severity of fetal anemia (middle cerebral artery Doppler), and means to intervene (percutaneous umbilical blood sampling and intrauterine transfusion) the sanction is heroic and sequela can’t always be fully prevented. Therefore it appears more reasonable to emphasize on prophylaxis knowing that once sensitized, the administration of Rhogam becomes futile.
We offer the full dose scheduled at 28 weeks and another repeated dose postpartum. Should one have experienced a first trimester miscarriage or abnormal bleeding during the pregnancy we recommend reduced dose or full dose depending on the timing and circumstances.