The effect of early and late umbilical cord clamping on neonatal hematocrit

Objective: To compare the effect of early and late cord clamping (LCC) on neonatal hematocrit at 2 and 18 h of life. Study Design: In this double-blind randomized trial, 64 healthy fullterm vaginally born neonates were randomly allocated to either early (30 s) or late (3 min) umbilical cord clamping. During the interval between delivery and cord clamping, the attendant held the neonate supine at the level of the introitus. Neonatal venous hematocrit was measured at 2 and 18 h of life. Result: Neonatal hematocrit at 2 h of life (61 +/- 4.9 vs 61.6 +/- 4.5%) and 18 h of life (56.9 +/- 4.1 vs 56.2 +/- 3.9%) was not significantly different between the two groups. This was also true for neonatal polycythemia (20 vs 23.5%). In the LCC group, placental residual blood volume (PRBV) was 39.5% lower and estimated neonatal blood volume (ENBV) was 7.1% higher than that in the early cord clamping (ECC) group (P<0.001). Conclusion: Late cord clamping does not lead to a significant difference in the hematocrit level of the neonate or neonatal polycythemia, but is associated with a significant increase in ENBV and a significant decrease in PRBV. Further trials should examine the effect of delaying cord clamping for a longer period of time or changing the position that the neonate is held in to determine whether these variations result in more clinically significant results.