title: The effect of Leboyer delivery on blood viscosity and other hemorheologic parameters in term neonates.
abstract: OBJECTIVE
  This study was done to compare postnatal alterations in blood viscosity, hematocrit value, plasma viscosity, red blood cell aggregation, and red blood cell deformability in term neonates undergoing both early umbilical cord clamping and delivery according to the Leboyer method.
  
  
  METHODS
  The umbilical cords of 15 healthy, term infants were clamped within 10 seconds of birth (early cord clamping), and 15 infants delivered according to the Leboyer method were placed on the mother's abdomen, and the umbilical cords were clamped 3 minutes after birth. Hemorheologic parameters were studied in umbilical cord blood at 2 hours, 24 hours, and 5 days from the time of delivery.
  
  
  RESULTS
  The residual fetal placental blood volume decreased from 45 +/- 8 ml/kg (x +/- SD) after early cord clamping to 25 +/- 5 ml/kg after delivery by the Leboyer method. After Leboyer-method delivery, the hematocrit value rose from 48% +/- 5% at birth to 58% +/- 6% 2 hours after delivery, 56% +/- 7% at 24 hours, and 54% +/- 8% after 5 days. Blood viscosity in the Leboyer-method group increased by 32% within the first 2 hours but did not change significantly during the following 5 days. Plasma viscosity, red blood cell aggregation, and red blood cell deformability were not affected by the mode of cord clamping.
  
  
  CONCLUSIONS
  Delivery by the Leboyer method leads to a significant increase in blood viscosity as a result of increasing hematocrit value, whereas other hemorheologic parameters are similar to those of infants with early cord clamping.
authors.affiliation: Department of Pediatrics, University of Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Nelle
authors.forename: E P
authors.initials: EP
authors.lastname: Zilow
authors.forename: M
authors.initials: M
authors.lastname: Kraus
authors.forename: G
authors.initials: G
authors.lastname: Bastert
authors.forename: O
authors.initials: O
authors.lastname: Linderkamp
mesh_terms: D001809:Blood Viscosity; D003250:Constriction; D036861:Delivery, Obstetric / Q000379:methods*; D004903:Erythrocyte Aggregation; D004907:Erythrocyte Deformability; D005260:Female; D006400:Hematocrit; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D011247:Pregnancy; D012212:Rheology; D013997:Time Factors; D014470:Umbilical Cord