In VLBW infants, during their first week of life (the time when their risk of intraventricular hemorrhage is greatest), a low hematocrit is associated with a significant prolongation in the bleeding time.

Thrombocytopenia is one of the most common hematological problems among neonates in the neonatal intensive care unit (NICU), but in the majority of cases the kinetic mechanism responsible is unclear. This review focuses on both traditional and innovative methods used to evaluate the mechanisms responsible for thrombocytopenia in neonates, and analyzes the data generated from those methods. Conclusion: Results of studies using new methods for evaluating thrombocytopenia, coupled with recent descriptions of marrow megakaryocyte mass, suggest that decreased platelet production complicates most cases of thrombocytopenia among neonates in the NICU.