Guidelines Favor Restrictive Transfusion Threshold for Very Preterm Neonates

Newly published guidelines recommend a restrictive transfusion strategy for very preterm newborns. The consensus statement was developed by an international group of experts that included neonatologists, hematologists and transfusion medicine specialists and published in JAMA Network Open.

The guidelines recommend transfusion thresholds based on postnatal week, as well as the need for respiratory support. For newborns requiring no or little respiratory support, thresholds of 10, 8.5 and 7 g/dL are recommended for postnatal weeks 1, 2 and 3, respectively. For preterm newborns (defined as born at 30 weeks gestation or earlier) requiring respiratory support, the guidelines recommend thresholds of 11, 10 and 9 g/dL, respectively. Respiratory support is defined as invasive mechanical ventilation, continuous positive airway pressure or noninvasive intermittent positive pressure ventilation, or a nasal cannula flow rate of at least 1 L/minute.

The group called the recommendations conditional with a moderate certainty of evidence – meaning that “while most parents would desire the given recommendation, many would not, due to variability in individual values, preferences and resources.” They added that the recommendations require “careful consideration of individual patient factors.”

The recommendations fill a gap in red blood cell (RBC) transfusion decision-making. AABB periodically updates RBC transfusion guidelines for adults. Multifactorial anemia is common among very preterm neonates, yet clinicians caring for very preterm newborns have had no evidence-based guidelines for when RBC transfusion is needed.

“The decision to transfuse RBCs requires assessment of the balance between benefits and harms. Transfusions of RBCs may improve cerebral oxygenation, which has been associated with lower risk of death or neurodevelopmental impairment. However, RBC transfusions may increase risks of serious adverse effects,” the group noted.

The recommendations are based on a Grading of Recommendations, Assessment, Development, and Evaluation (GRADE)-based evaluation of six randomized controlled trials including 3,482 newborns (51.3% females). The trials all compared restrictive versus liberal transfusion thresholds in neonates.

The expert group developed two key questions examining short-term and long-term outcomes based on liberal versus restrictive transfusion thresholds. Short-term outcomes included survival, short-term morbidity (including bronchopulmonary dysplasia, intraventricular hemorrhage, periventricular leukomalacia, retinopathy of prematurity and necrotizing enterocolitis) and transfusion-related serious adverse events. Long-term outcomes included mortality, neurodevelopmental disability at 2 years corrected and school age, as well as social and behavioral problems at school age.