Mineral composition of meconium: effect of prematurity.

OBJECTIVES

We hypothesized that the concentration of major essential mineral elements in meconium correlate with gestational age (GA) or birth weight. To verify this premise we determined the concentration in meconium of calcium, magnesium, phosphorus, copper, zinc, iron, and manganese.

METHODS

Thirty-four appropriate for age singleton infants without major congenital anomalies were divided into four GA groups (in weeks): 24 to 28; 29 to 33; 34 to 37; 38 to 42, or in birth weight groups (in g): < 1500; 1500-1999; 2000-2499; > or = 2500. Meconium was collected until the appearance of transitional stools and lyophilized for analysis.

RESULTS

When adjusted for birth weight, the concentrations of calcium, copper, iron and phosphorus were higher in the meconium of 24 to 28 week GA infants than in those of the 38 to 42 week GA newborns. Birth weight adjusted copper concentration was highest in the 29 to 33 week GA group, while the remaining elements did not change across the range of GA. Meconium copper concentration in infants born with < 2000 g was higher than in those born with a weight > or = 2500 g.

CONCLUSIONS

These results could serve as normative data of a noninvasive examination of the mineral nutritional "history" of the fetus, and, eventually, to better evaluate possible neonatal deficiencies in infants with intrauterine growth retardation or other types of complicated intrauterine courses.