Retinol concentration in maternal and cord serum: Its relation to birth weight in healthy mother-infant pairs

Background: Vitamin A is an essential micronutrient for the development and growth of the fetus. The objective of this study was to identify a possible association between low serum retinol and birth weight in healthy mother-infant pairs in Southern Israel. A secondary objective was to examine ethnic differences in maternal and cord serum retinol. Methods: Serum retinol was measured at delivery from pairs of healthy mothers and healthy mature newborns. Results: Of the 313 mother-infant pairs studied, 56% were Jews and 44% Bedouins. The proportion of infants with birth weight of 2500-2999 g was greater among mothers with lower serum retinol (<0.7 μmol/l) compared to mothers with normal serum retinol (≥0.7 μmol/l) (p<0.001). Cord retinol <0.7 μmol/l was more frequent in infants with birth weight 2500-2990 g compared to infants with birth weight ≥3000 g (p=0.006). Using a split model and stepwise multiple regression analysis, infant's birth weight was significantly influenced by cord retinol concentration in infants born to mothers with low serum retinol; gestational age and cord retinol alone explained 27% of the variability of birth weight in this group. A higher proportion of Bedouin than Jewish infants had serum retinol <0.7 and <0.35 μmol/l (both p<0.001). Conclusion: Low cord and maternal serum retinol may reflect poor vitamin A status of the newborn and the mother, which in turn may affect fetal growth.