Meconium mineral content in small for gestational age neonates

The mineral concentration of meconia of small for gestational age (SGA) newborns were compared with those of appropriate for gestational age (AGA) newborns of similar gestational ages (GA) to determine whether differences may provide clues of possible nutritional deficits of SGA infants, given that levels of meconium minerals could indicate the use of minerals by the fetus and the sufficiency of the maternal supply of minerals. Twenty-one SGA and 24 AGA newborns were included. Eleven SGA and 15 AGA were < or = 35 weeks GA. Ten SGA and nine AGA infants were > or = 36 weeks GA. All meconia from each neonate was processed and assayed for iron, zinc, copper, manganese, calcium, magnesium, and phosphorus. In the < or = 35-week subgroups, the SGA infants had lower meconium iron and manganese concentrations than that of the AGA. Among > or = 36-week newborns, SGA infants had a higher birthweight-adjusted copper concentration than AGA infants, but no differences were observed for the remaining elements. Lower iron and manganese meconium in < or = 35-week SGA infants may reflect either a greater use or a decreased maternal supply. The higher birthweight-adjusted meconium copper in the > or = 36-week SGA infants may be due to a comparatively reduced fetal use or increased maternal supply. These data may assist in clarifying potential mechanisms affecting intrauterine growth and/or potential nutrient deficits in the neonatal period.