Effect of vitamin K administration on acarboxy prothrombin (PIVKA-II) levels in newborns.

PIVKA-II (protein induced by vitamin K absence or antagonist-II) was measured in two groups of newborns, one group being given 5 mg vitamin K at birth and the other untreated. The untreated group had a significantly higher proportion of PIVKA-II positive babies at 3 and 5 days of age than did the treated group. When vitamin K was administered to newborn babies whose normotest levels were less than 30%, it was found that the higher the pre-treatment PIVKA-II levels the greater the response to vitamin K, as monitored by the normotest. Thus PIVKA-II levels might be more useful than a coagulation test, since the low activity of vitamin K dependent coagulation factors sometimes reflects not vitamin K deficiency but impaired production of these factors because of immaturity. The findings support the view that vitamin K given prophylactically at birth will help to prevent neonatal bleeding.