Article Text
Abstract
Background: Vitamin K deficiency bleeding (VKDB) in infants is a rare but serious worldwide problem, particularly in Southeast Asia. Apart from exclusive breast-feeding, little is known of materno-fetal risk factors that predispose to VKDB.
Objectives: To assess (a) the relationships between functional vitamin K insufficiency in a large cohort of Thai mothers to that of their newborn infants and (b) the importance of delivery risk factors and maternal intakes of vitamin K as determinants of neonatal vitamin K status.
Methods: Vitamin K status was assessed by measuring undercarboxylated prothrombin (PIVKA-II) in 683 mothers and in the cord blood of their babies by sensitive immunoassay. Dietary phylloquinone (vitamin K1; K1) intakes were assessed in 106 of these mothers by food frequency questionnaire.
Results: Babies were categorized as ‘normal’ (n=590) or ‘high-risk’ (n=93) according to birth weight and delivery type. PIVKA-II was detectable (>0.15 Arbitrary Units (AU)/ml) in 85 mothers (12.4%) and 109 babies (16.0%) with median levels of 0.78 and 1.04 AU/ml in mothers and babies, respectively. ‘High-risk’ babies had both a higher median detectable PIVKA-II concentration than ‘normal-risk’ babies (3.1 vs. 1.0 AU/ml, p=0.02) and a higher prevalence of clinically relevant (>5.0 AU/ml) concentrations (p=006). Mothers with K1 intakes below the U.S. recommended ‘Adequate Intake’ for pregnancy (<90 µg/d) had a higher prevalence of detectable PIVKA-II (18.8%) than those with adequate intakes (3.3%) (p=0.01).
Conclusions: Functional, clinically relevant, vitamin K insufficiency was more common in ‘high-risk’ than ‘normal-risk’ newborns. Vitamin K insufficiency in mothers was linked to lower dietary K1 intakes during pregnancy.