Supplementation of vitamin K in pregnant women receiving anticonvulsant therapy prevents neonatal vitamin K deficiency.

Abstract

The null hypothesis of this study is that extra vitamin K administered to pregnant women on a regimen of enzyme-inducing anticonvulsant therapy will not decrease the frequency of symptoms of vitamin K deficiency in their neonates. A multicenter case-control study was performed on 16 pregnant women on anticonvulsant therapy who received 10 mg of vitamin K1 daily from 36 weeks of pregnancy onward. Concentrations of PIVKA-II (protein induced by vitamin K absence for factor II) and of vitamin K1 were determined in cord blood and compared with those in 20 controls. In none of 17 cord samples was PIVKA-II detectable, compared with 13 of 20 in controls (chi 2, p < 0.001). Median cord vitamin K1 level was 530 pg/ml compared with below detection limit in most controls. Antenatal vitamin K1 treatment decreases the frequency of vitamin K deficiency in neonates of mothers on anticonvulsant therapy.