Reference ranges for circulating white blood cells and platelets in Very Low Birth Weight Infants (VLBW). 1301

Very low birth weight infants have different values of circulating neutrophils when compared to Manroe's reference ranges for neutrophil indices. In fact, using these reference ranges would diagnose a large number of premature infants with neutropenia. Recently, these reference ranges have been predicted to be much lower in infants <1500 gms however the ranges were not evaluated by different gestational ages (Mouzinho et al, Pediatrics, 1994). This study examined the circulating levels of white blood cells, neutrophils, and platelets in VLBW infants within the first 12 hours of life to determine normative values. Table

Table 1

The platelet counts in this population of VLBW infants do not demonstrate thrombocytopenia. The circulating white cell values are lower than described and the circulating neutrophil values are lower than values described in Manroe's reference. The neutrophil reference ranges identified in this population, at less than 12 hours of life, may well be a normal finding as suggested by Mouzinho et al. If so, lower circulating neutrophil values may be an expected finding in the VLBW infant admission white cell count.