Intrapartum levels of trace metals in maternal blood in relation to umbilical cord blood values: lead, iron, copper, zinc.

The study was designed to measure the gradients of lead, iron, copper and zinc from maternal blood to cord blood in pregnant urban and rural women. The concentrations of iron, copper, zinc and lead were measured by means of atomic absorption spectometry (AAS) in whole blood of 100 normal parturients and 92 of their neonates. Levels of lead in cord blood were not significantly different from those in maternal blood. This ratio was associated with similar iron and zinc ratios. Neonatal birth weight was negatively correlated with maternal copper levels, whereas cord blood zinc values positively correlated with placental weight. Rural women showed higher maternal to cord blood lead ratios than urban women. The implications of these findings are discussed.