A newborn with positive antiglobulin test whose mother took methyldopa in pregnancy.

Methyldopa is known to cause the production of autoantibodies against red blood cells (RBCs), leading to a positive direct antiglobulin test (DAT) and hemolytic anemia. In about 20% of patients taking methyldopa, IgG autoantibodies develop against RBCs. However, most of the patients do not have hemolysis. A small percentage of such DAT-positive patients, about 2% of those taking methyldopa, develop an autoimmune hemolytic anemia (AIHA). The fact that the DAT is positive in the newborn with unconjugated hyperbilirubinemia is considered as an isoimmune hemolytic disease caused by blood group incompatibility. In this article, a newborn with jaundice and positive DAT without hemolysis is reported. Her mother had the history of taking methyldopa in her pregnancy. Thus, when newborns are detected with positive DAT and jaundice, without blood group incompatibility, mothers should be questioned regarding drugs used in their pregnancy.