Direct intravascular fetal blood transfusion by fetoscopy in severe Rhesus isoimmunisation.

Two fetuses with severe anaemia due to rhesus incompatibility each received two early blood transfusions (between 23 and 25 weeks) by fetoscopy. The blood was given directly into an umbilical vessel, either at the umbilicus or at the placental cord insertion. Fetal blood samples were taken before and after transfusion to assess the haematological status of the fetus. One grossly hydropic fetus survived.