Increased incidence of neonatal vitamin K deficiency resulting from maternal anticonvulsant therapy.

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.

31P nuclear magnetic resonance and zero-point titration compared for measuring free magnesium concentration in erythrocytes.

Intracellular ionized magnesium concentrations ([Mg2+]i) were measured in erythrocytes by 31P nuclear magnetic resonance (NMR) and zero-point titration in 14 controls and seven patients with renal magnesium loss. The mean intracellular ionized magnesium concentration in controls measured by 31P NMR was 0.20 (SD 0.

Reference values of magnesium and potassium in mononuclear cells and erythrocytes of children.

Reference values for magnesium and potassium contents of mononuclear cells and erythrocytes were estimated in cord blood and in children from infancy through adolescence. No differences were detected between results for boys and girls. The mononuclear magnesium content was independent of age and was within the adult range of values.