Hemolytic disease in ABO-incompatible preterm infants

A new study by Israeli investigators shows that hemolytic disease and neonatal jaundice are absent in some ABO-incompatible infants delivered preterm, shedding increased light on the impact of gestational age on hemolytic reactions. The findings were published in Pediatric Blood & Cancer.

Data are lacking on ABO incompatibility in preterm infants, said the researchers, who retrospectively assessed medical records of 118 ABO-incompatible infants born at 29 to 34 weeks’ gestation and 118 controls matched for gestational age. All of the deliveries were at the Sheba Medical Center Tel-Hashomer between 2009 and 2012.

Maternal and neonatal outcome parameters were similar in both groups, as were hematocrit levels and need for blood transfusion throughout hospitalization. During the first 10 days of life, the ABO-incompatible infants did have higher bilirubin levels but they did not differ from the controls in need for phototherapy.

When the researchers divided the groups by gestational age, they found differences in hematological or jaundice factors for infants born at 29 to 31 weeks’ gestation. Direct antiglobulin test (DAT) results were higher, however, among ABO-incompatible infants born at 32 to 34 weeks’ gestation than in the controls born at similar gestational ages (7% vs 0%, P = 0.014) and they also had higher bilirubin levels.