title: Can prenatal vitamin K1 (phylloquinone) supplementation replace prophylaxis at birth?
abstract: OBJECTIVE
  To assess the effect of prenatal vitamin K1 on the coagulation status of newborns.
  
  
  METHODS
  We measured noncarboxylated prothrombin and performed the Normotest in two groups of 5-day-old infants whose mothers were given oral vitamin K1, 10 mg/day for 2 weeks at least 10 days before delivery, or were untreated.
  
  
  RESULTS
  Noncarboxylated prothrombin was found in one of 74 treated women and 13 of 186 controls, a nonsignificant difference. The mean (+/- standard deviation) Normotest value was 59.6 +/- 10.1% (range 38.9-84.4) for the treated group and 53.4 +/- 9.9% (range 16.3-89.9) for the controls, a statistically significant difference (P < .001).
  
  
  CONCLUSIONS
  Based on the Normotest results, we suggest that vitamin K crosses the placenta and persists to activate the vitamin K-dependent coagulant factors until at least the fifth day of life. Thus, prenatal vitamin K1 administration may replace prophylaxis at birth.
authors.affiliation: Department of Obstetrics and Gynecology, Oita Medical University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Anai
authors.forename: Y
authors.initials: Y
authors.lastname: Hirota
authors.forename: J
authors.initials: J
authors.lastname: Yoshimatsu
authors.forename: M
authors.initials: M
authors.lastname: Oga
authors.forename: I
authors.initials: I
authors.lastname: Miyakawa
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange / Q000502:physiology; D011247:Pregnancy; D011295:Prenatal Care; D010837:Vitamin K 1 / Q000627:therapeutic use*; D014813:Vitamin K Deficiency / Q000517:prevention & control*; D006475:Vitamin K Deficiency Bleeding / Q000517:prevention & control*
chemical_list: D010837:Vitamin K 1