An O-positive mother gave birth to an A- negative baby. Afte…

An O-positive mother gave birth to an A- negative baby. After 24 hours the newborn’s bilirubin level rose to 18 mg/dL. A DAT performed on the cord blood specimen was positive with polyspecific AHG and anti-IgG reagents. It is probable that _______ from maternal circulation is coating the newborn’s red blood cells.