Meconium ferritin amounts and birth size of neonates: a pilot study

Purpose

Ferritin amounts that accumulate in the meconium may provide new postnatal insights into intrauterine iron homeostasis and neonatal preparedness for the postnatal period. The most dynamic increases in fetal iron stores and fetal growth occur during the third trimester.

Materials and methods

This study involved 122 neonates born between 36 and 41 weeks of gestation, with birth weights from 2650 ​g to 4960 ​g and birth lengths ranging from 50 ​cm to 60 ​cm. Ferritin amounts per gram of meconium were determined via ELISA in the first meconium passed after birth.

Results

A significant week-by-week increase in the birth weight and length (p ​< ​0.05) was accompanied by decreasing meconium ferritin amounts (p ​= ​0.021) across the gestational age range of 36–41 weeks. There were negative correlations (p ​< ​0.05) between the systematic decrease in meconium ferritin amounts and the gestational age across the same range (r ​= ​-0.18) and between ferritin amounts and the birth weight and length of newborns (r ​= ​-0.20 and r ​= ​-0.31). Neonates born at 36–37 weeks of gestation had lower birth weight and length, while their meconium ferritin amounts were nearly twice as high as in neonates born at 38–39 weeks or 40–41 weeks (p ​< ​0.05).

Conclusions

Systematic decreases in meconium ferritin amounts from 36 to 41 weeks of gestation may suggest a gradual and gestational age-appropriate maturation of the mechanisms responsible for adaptation of the fetus to postnatal life. Determining a cut-off value for meconium ferritin amounts could aid in optimal management of newborns after birth.