Objective: The null hypothesis of our study is that the incidence of vitamin K deficiency in mother-infant pairs exposed to anticonvulsant drugs is not higher than in controls.
Study design: In this multicenter observational case-control study, 25 pregnant women receiving anticonvulsant therapy and 25 pregnant controls were studied for PIVKA-II (protein induced by vitamin K absence of factor II) and vitamin K1 concentrations at 32 weeks' gestation and at delivery.
Results: PIVKA-II was detectable in 54% of cord samples of the anticonvulsant group and in 20% of controls (chi 2, p = 0.01). In both groups vitamin K1 cord blood levels were predominantly below the detection limit. Maternal vitamin K1 concentrations were lower in women with epilepsy than in controls (Wilcoxon's rank sum test, p < 0.05), but PIVKA-II was rarely present.
Conclusions: The incidence of vitamin K deficiency is increased in neonates exposed to anticonvulsant drugs prenatally. Their mothers, however, are rarely vitamin K deficient.