The risk of developing severe bronchopulmonary dysplasia: evaluating associations with the nucleated red blood cell count at birth and volume of transfusions received.

INTRODUCTION

The nucleated red blood cell (NRBC) count at birth and blood transfusions received prior to 36 weeks postmenstrual age (PMA) are both associated with the risk of developing retinopathy of prematurity (ROP). We examined the association of these two factors with the risk of developing bronchopulmonary dysplasia (BPD).

METHODS

We retrospectively analyzed records of infants in five Intermountain Health Neonatal Intensive Care Units during the past four years who were born <32 weeks gestation, had an NRBC count at birth, and BPD scoring. We expressed NRBC counts as multiples of the control mean (MoM), with the control mean determined by the refineR algorithm. We report red blood cell (RBC) and platelet transfusions received before 36 weeks PMA.

RESULTS

The NRBC count of 896 infants was not independently associated with BPD risk. However, RBC transfusions received before 36 weeks were associated with BPD risk (p < 0.01). All 39 infants who developed severe BPD received multiple RBC transfusions (volume range 36-501 mL/kg) and 15 (38%) also received platelet transfusions (range 16-489 mL/kg).

CONCLUSIONS

An elevated NRBC count at birth is not an independent risk factor for developing severe BPD, but the number and volume of RBC transfusions received are associated factors.