Transfusion of Prematures Trial
Transfusion of Prematures (TOP) Trial: Does a Liberal Red Blood Cell Transfusion Strategy Improve Neurologically-Intact Survival of Extremely-Low-Birth-Weight Infants as Compared to a Restrictive Strategy?
The objective of the TOP trial is to determine whether higher hemoglobin thresholds for
transfusing ELBW infants resulting in higher hemoglobin levels lead to improvement in the
primary outcome of survival and rates of neurodevelopmental impairment (NDI) at 22-26 months
of age, using standardized assessments by Bayley.
Long-term outcomes of extremely low birth weight (ELBW) preterm infants, those weighing less
than or equal to 1000 g at birth, are poor and pose a major health care burden. Virtually
all of these infants are transfused, but at inconsistent hemoglobin (Hgb) thresholds.
The investigators propose in TOP to randomize infants less than or equal to 1000 g BW and <
29 weeks GA to receive red blood cell (RBC) transfusions according to one of two strategies
of Hgb thresholds, either a high Hgb (liberal transfusion) or a low Hgb (restrictive
transfusion) algorithm. It is currently unknown which transfusion strategy is superior. TOP
is powered to demonstrate which strategy reduces the primary outcome of death or
neurodisability in survivors at 22-26 months.
A secondary study entitled "Effect of Blood Transfusion Practices on Cerebral and Somatic
Oximetry", also known as the NIRS study, will determine differences in cerebral oxygenation
and fractional tissue oxygen extraction with NIRS between high and low hemoglobin threshold
groups during red blood cell transfusions. The investigators also propose to determine
whether abnormal cerebral NIRS measures are a better predictor of NDI than hemoglobin alone
and whether abnormal mesenteric NIRS measures are associated with the development of NEC
within the 48 hours following a transfusion.
- Birth weight less than 1000 grams.
- Gestational age at least 22 weeks but less than 29 completed weeks
- Admitted to the NICU within 48 hours of life
- Considered nonviable by the attending neonatologist
- Cyanotic congenital heart disease
- Parents opposed to the transfusion of blood
- Parents with hemoglobinopathy or congenital anemia
- In-utero fetal transfusion
- Twin-to-twin transfusion syndrome
- Isoimmune hemolytic disease
- Lack of parental consent
- Severe acute hemorrhage, acute shock, sepsis with coagulopathy, or need for
- Prior blood transfusion on clinical grounds beyond the first 6 hours of life
- High probability that the family is socially disorganized to the point of being
unable to attend follow-up at 22-26 months.