Cheryl Carlson

According to Avery's text. It is possible for Group A or B infants born to incompatable A or B mothers will have a small chance of a positive combs test, though unlikely to cause significant hyperbilirubinemia. "Infants born of ABO-incompatible mother–infant pairs who have a negative direct Coombs test appear to be at no greater risk for developing hyperbilirubinemia than their ABO-compatible counterparts (Ozolek et al., 1994), and the development of significant hyperbilirubinemia in such neonates should prompt an evaluation for a cause other than isoimmunization (Herschel et al., 2002). Similarly, group A or B infants born to incompatible group B or A mothers are not likely to manifest symptomatic ABO hemolytic disease, and less than 1% will have a positive direct Coombs test (Ozolek et al., 1994)."