Extremely low birthweight infants become anaemic during their care in the neonatal intensive care unit because of the physiological anaemia experienced by all newborn infants compounded by early umbilical cord clamping, blood loss by phlebotomy for laboratory monitoring and delayed erythropoiesis. The majority of these infants receive transfusions of packed red blood cells, usually based on haemoglobin values below a certain threshold.

Previous smaller studies have not given clear guidance with respect to the haemoglobin thresholds that should trigger transfusions or even if this is the best way to decide when to transfuse an infant. Two large clinical trials of similar design comparing higher and lower haemoglobin thresholds for transfusing extremely low birthweight infants were recently published, the ETTNO and TOP trials. These trials found reassuringly conclusive and concordant results.

Unless information to the contrary emerges from the school-age examinations of the TOP trial infants, practitioners should be comfortable using transfusion thresholds within the ranges used in the ETTNO and TOP trials.

Author: Edward F Bell

Correspondance to : Dr Edward F Bell, Pediatrics, The University of Iowa Roy J and Lucille A Carver College of Medicine, Iowa City, Iowa 52240, USA; edward-bell@uiowa.ed

Bell EF. Arch Dis Child Fetal Neonatal Ed 2022;107:F126–F130