The effect of early and late cord-clamping on blood viscosity and other hemorheological parameters in full-term neonates.
This study was done to compare postnatal alterations in blood viscosity (capillary viscometer) and its determinants: hematocrit, plasma viscosity (capillary viscometer), red cell aggregation (Myrenne aggregometer) and red cell deformability (rheoscope) in the first five days of postnatal life in full-term neonates with early (< 10 s) and late (3 min) cord-clamping. The fetal blood volume of the placenta ("residual placental blood volume") decreased from 52 +/- 8 ml/kg of neonatal body weight after early cord-clamping to 15 +/- 4 ml/kg after later cord-clamping. Neonatal blood volume, calculated as the difference between an assumed total feto-placental blood volume of 115 ml/kg and the measured fetal blood volume of the placenta, was 50% higher in the late cord-clamped infants than in the early cord-clamped infants. Both groups showed similar viscosity, hematocrit and other rheological parameters in cord blood. In the infants with early cord-clamping, the hematocrit decreased from 0.48 +/- 0.04 l/l at birth to 0.43 +/- 0.6 l/l after 24 h (p < 0.05). Whole blood viscosity did not change significantly with age. After late cord-clamping, the hematocrit rose from 0.50 +/- 0.04% at birth to 0.63 +/- 0.05 l/l at 2 h of age (p < 0.005) and dropped to 0.59 +/- 0.5 l/l (p < 0.05) at 24 h. Blood viscosity increased by 40% (p < 0.001) within the first 2 h, but did not change significantly during the following five days. In both groups, plasma viscosity and red cell aggregation increased significantly (p < 0.05) on day 5 due to significant increases in total plasma protein and fibrinogen concentrations (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Linderkamp
O
O
Department of Pediatrics, University of Heidelberg, Germany.
Nelle
M
M
Kraus
M
M
Zilow
E P
EP
D001798:Blood Proteins / Q000032:analysis; D001800:Blood Specimen Collection / Q000379:methods* / Q000592:standards; D001809:Blood Viscosity; D001810:Blood Volume; D004903:Erythrocyte Aggregation; D004907:Erythrocyte Deformability; D005069:Evaluation Studies as Topic; D005312:Fetal Blood / Q000737:chemistry*; D006400:Hematocrit; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D010949:Plasma / Q000737:chemistry; D012212:Rheology; D013997:Time Factors; D014470:Umbilical Cord
D001798:Blood Proteins