Selenium concentrations in maternal and umbilical cord blood at 24-42 weeks of gestation: basis for optimization of selenium supplementation to premature infants.

BACKGROUND & AIMS: Selenium (Se) deficiency may have deleterious effects on premature infants. Umbilical cord (UC) Se concentrations presumably reflect fetal Se concentrations and represent reference values that should be achieved in premature infants. We aimed to establish reference data of Se serum concentrations in parturient women and their neonates across gestation. SUBJECTS AND METHODS: Parturient mothers and their newborn infants born after 24-42 weeks of gestation were enrolled. Only appropriate for gestational age (GA) singleton infants were included. Se serum concentrations were measured by atomic absorption spectrometry, in blood samples from parturient mothers and their infants (umbilical blood). Demographic, perinatal and labor data were obtained, and their correlations with umbilical Se serum concentrations, maternal Se serum concentrations, and the maternal-umbilical Se difference were examined.
RESULTS: UC Se serum concentrations increased as gestation progressed (P<0.01). A statistically significant linear relationship was found between UC Se serum concentrations and GA (R=0.341, P<0.0001), birth weight (R=0.237, P=0.002), and 5-min Apgar score (R=0.202, P<0.01). Using multiple regression analysis, only GA was significantly associated with UC serum Se concentration (P=0.012). Maternal Se serum concentration were stable throughout gestation, and maternal-umbilical Se difference was negatively correlated with GA (R=-0.337, P<0.0001) and birth weight (R=-0.369, P<0.0001).
CONCLUSIONS: UC Se serum concentration increases and the maternal-umbilical Se difference declines with gestation progression, probably reflecting fetal accretion of Se. With the current Se supplementation in premature infants, Se concentrations are lower than those measured in our study. We, therefore, suggest a two-fold increase or more in the recommended Se dosage.