Purpose of review: There have been several recent randomized controlled trials collectively aimed at either the prevention or the management of anemia of prematurity. We aim to summarize evidence on prevention, management and long-term outcomes.
Recent findings: Current guidelines for red blood cell transfusion are based on expert opinion and vary. Conservative transfusion policies can reduce the number of transfusions, but other benefits are more uncertain. Delivery room prevention by using delayed cord clamping or cord milking is promising, but requires long-term outcome assessments in preterms. Some measures of hypoxemia to guide 'need' for transfusion have potential, but are not yet ready for general use. Pragmatic management trials have compared a 'restrictive' with a 'liberal' policy with respect to effects on clinically relevant outcomes by neonatal ICU discharge, but conclusions have differed. Follow-up data to 24 months is available for only one study, which showed no benefit in the primary outcome of death and or neurodisability. However, an a-priori subgroup analysis shows benefit in the cognitive Bayley scores, favoring high hemoglobins.
Summary: This field is plagued by lack of replication, small studies and speculative findings. Hence, the risk-benefit ratio of blood transfusions for preterms still needs adequate definition. Evidence suggests that a restrictive hemoglobin, hematocrit threshold or both for transfusion decreases the number of blood transfusions in preterm infants. However, uncertainty remains on long-term outcomes. Large randomized controlled trials are needed to clarify the safety of a lower threshold or the longer-term benefit of a high threshold.