Is a small platelet mass associated with intraventricular hemorrhage in very low-birth-weight infants?

OBJECTIVE: We sought to determine whether, among very low-birth-weight (VLBW) neonates, the platelet mass was associated with common perinatal factors, and whether a low platelet mass in the first days following birth was associated with a higher incidence and/or severity of intraventricular hemorrhage (IVH).

STUDY DESIGN: This was a cross-sectional, retrospective cohort analysis of VLBW infants admitted to a level 3 neonatal intensive care unit from June 2003 to July 2006, n=408. Platelet mass was calculated and recorded on the day of birth and for 2 consecutive days thereafter. All neonates had a screening cranial sonogram on day 4 of life. Statistical analysis included analysis of variance and Mann-Whitney U-test.

RESULT: Neonates born to mothers with pre-eclampsia had a smaller platelet mass (1921 fl/nl ± 603 vs 2297 fl/nl ± 747; P<0.01). The same was found among neonates with intrauterine growth restriction (IUGR). In contrast, neonates born after histological chorioamnionitis had a larger platelet mass (2400 fl/nl ± 749 vs 2036 fl/nl ± 674; P<0.01). No effect of platelet mass, measured on the day of birth, was observed related the outcomes of IVH, severe IVH or death. However, those with a platelet mass <10th percentile on the 2 subsequent days following birth were more likely to have severe IVH or death.

CONCLUSION: Among VLBW neonates, pre-eclampsia and IUGR are associated with a lower platelet mass, owing to their effect on platelet count. Histological chorioamnionits is associated with a larger platelet mass. A mass <10th percentile on the days following birth was associated with severe IVH and/or death, but it remains unclear whether this is a cause of, or an effect of, the IVH.