Antenatal vitamin K therapy of the low-birth-weight infant.

Abstract

The purpose of our study was to determine whether maternal vitamin K1 administered antenatally improved global coagulation parameters and the levels of specific vitamin K-dependent proteins in low-birth-weight infants. Thirty-three preterm mothers admitted in labor were assigned in a prospective, blinded fashion to receive either intramuscular vitamin K1 (17) or placebo (16). At delivery cord blood samples were tested for prothrombin time, activated partial thromboplastin time, factor II and protein C activity, and antigen levels. Statistical analysis was by Student t test. No statistically significant differences could be demonstrated with regard to group mean values for global tests (prothrombin time, activated partial thromboplastin time) or specific vitamin K-dependent protein levels (factor II, protein C) in newborns whose mothers received antenatal vitamin K compared with those who did not. These results would suggest that antenatal vitamin K1 therapy to mothers < 32 weeks' gestation has no significant effect on the level of vitamin K-dependent factors in the fetus.