Severe neonatal protein C deficiency: prevalence and thrombotic risk

J Pediatr. 1991 Nov;119(5):793-8. doi: 10.1016/s0022-3476(05)80305-1.


Severe deficiencies of protein C, a pivotal coagulation-regulatory protein, have been reported in neonates as an apparently transient condition. In this prospective study, cord blood was collected at 193 deliveries and assays of protein C were correlated with clinical status, other coagulation results, and outcome. Protein C levels of less than 0.1 unit/ml were found most frequently in preterm infants with respiratory distress, infants of diabetic mothers, and infants of twin gestations. Levels of protein C correlated with levels of factor VIII activity but did not correlate with markers of consumptive coagulopathy. A protein C level less than 0.1 unit/ml was significantly correlated with the subsequent onset of thrombosis, even when the effects of gestational age and birth weight were excluded. Low cord blood levels of protein C may reflect delayed maturation or increased turnover in certain infants and appear to convey an independent risk of thrombosis, but the critical concentration of protein C necessary to maintain neonatal hemostasis is not known.

MeSH terms

  • Antithrombin III / analysis
  • Blood Proteins / analysis
  • Carrier Proteins / blood
  • Colorado / epidemiology
  • Disseminated Intravascular Coagulation / blood
  • Disseminated Intravascular Coagulation / epidemiology*
  • Disseminated Intravascular Coagulation / etiology
  • Fetal Blood / chemistry
  • Glycoproteins / blood
  • Heparin Cofactor II / analysis
  • Humans
  • Infant, Newborn
  • Prevalence
  • Protein C / analysis
  • Protein C / antagonists & inhibitors
  • Protein C Deficiency*
  • Protein S
  • Risk Factors
  • Thrombosis / blood
  • Thrombosis / epidemiology*
  • Thrombosis / etiology


  • Blood Proteins
  • Carrier Proteins
  • Glycoproteins
  • Protein C
  • Protein S
  • Heparin Cofactor II
  • Antithrombin III