Zinc and copper in preterm neonates: relationship with breast milk

The study was conducted to assess copper and zinc levels in neonate's serum, mother's serum, neonate's hair and urine and to ascertain association between them. It is of concern whether zinc and copper deficiency is present at birth and maternal blood and breast milk zinc and copper levels have any effect on this. The study sample included 155 neonates with gestational age 26-41 wks and birth weight 0.550-3.800 kg. Mother's serum, breast milk, neonate's serum, hair, urine samples were analysed for zinc and copper by atomic absorption spectrophotometry. Gestational age was estimated either singly or by combination of date of last normal menses, fetal ultrasonography, and postnatal measures of physical and neurological development by clinical examination and weight by Secca electronic balance. The neonates were classified into term and preterm, small (SGA) and appropriate for gestational age (AGA). Neonates over 37 wks and 2.5 kg served as controls. To assess the dependency, relationship and effectiveness of quantitative predictive variables on the predictions of values, multiple regression analysis was used. Neonates between 26-30 wks gestational age and < 2.5 kg birth weight had significantly low serum zinc and copper. Breast milk zinc was low in mothers delivering preterm and < 2.5 kg neonates. Urinary copper and zinc levels were high in preterm appropriate for gestational age (Pre AGA) than term neonates. Multiple regression analysis revealed that neonate's serum Cu, serum Zn, hair Cu, hair Zn, urine Cu and urine Zn had contribution variability of 49.8%, 51.8%, 49.2%, 16.6%, 52.2% and 68.9%, respectively. The effect of mother's serum, breast milk, and neonate's serum copper and zinc collectively was significant for serum copper (F = 29.59) and hair zinc (F = 32.03). Preterm and low birth weight infants during subsequent growth and development should be supplemented with zinc and copper when on breast feeding.