Essential fatty acid composition of plasma phospholipids and birth weight:a study in term neonates

Background: Essential fatty acids (EFAs) in umbilical cord blood samples ar e associated with attained birth weight in premature infants and low-birth- weight neonates. Objective: The objective was to investigate relations between the EFA compo sition of cord and maternal plasma phospholipids and birth weight in term n eonates. Design: This was a cross-sectional study in 627 singletons born at term. Th e plasma phospholipid EFA composition of the mothers was determined by gas- liquid chromatography at study entry (less than or equal to 16 wk gestation ), at delivery, and in cord plasma at birth. Birth weights were normalized to SD scores. Results: In cord plasma, the dihomo-gamma -linolenic acid concentration was positively related to weight SD scores. Both arachidonic acid (AA) and doc osahexaenoic acid (DHA) were negatively related to weight SD scores. EFA-st atus indicators showed similar negative associations, whereas eicosatrienoi c acid concentrations were positively related to neonatal size. In maternal plasma, proportions of n-3 long-chain polyenes (LCPs) and n-6 LCPs decreas ed during pregnancy. Larger decreases in AA, DHA, n-3 LCP, and n-6 LCP frac tions were observed in mothers of heavier babies. Higher concentrations of LCPs in maternal plasma were, however, not related to a larger infant size at birth. Conclusions: A lower biochemical EFA status in umbilical cord plasma and a larger decrease in maternal plasma LCP concentrations are associated with a higher weight-for-gestational-age at birth in term neonates. Our findings do not support a growth-stimulating effect of AA or DHA; however, they do s uggest that maternal-to-fetal transfer of EFAs might be a limiting factor i n determining neonatal EFA status.