To understand better those factors relevant to the increment of rise in platelet count following a platelet transfusion among thrombocytopenic neonates.

We reviewed all platelet transfusions over 6 years in our multi-neonatal intensive care unit system.

For every platelet transfusion in 8 neonatal centers we recorded: (1) platelet count before and after transfusion; (2) time between completing the transfusion and follow-up count; (3) transfusion volume (mL/kg); (4) platelet storage time; (5) sex and age of platelet donor; (6) gestational age at birth and postnatal age at transfusion; and magnitude of rise as related to (7) pre-transfusion platelet count, (8) method of enhancing transfusion safety (irradiation vs pathogen reduction), (9) cause of thrombocytopenia, and (10) donor/recipient ABO group.

We evaluated 1797 platelet transfusions administered to 605 neonates (median one/recipient, mean 3, and range 1-52). The increment was not associated with gestational age at birth, postnatal age at transfusion, or donor sex or age. The rise was marginally lower: (1) with consumptive vs hypoproductive thrombocytopenia (P < .001); (2) after pathogen reduction (P < .01); (3) after transfusing platelets with a longer storage time (P < .001); and (4) among group O neonates receiving platelets from non-group O donors (P < .001). Eighty-seven neonates had severe thrombocytopenia (<20 000/μL). Among these infants, poor increments and death were associated with the cause of the thrombocytopenia.

The magnitude of post-transfusion rise was unaffected by most variables we studied. However, the increment was lower in neonates with consumptive thrombocytopenia, after pathogen reduction, with longer platelet storage times, and when not ABO matched.