The relationship between maternal blood cadmium, zinc levels and birth weight of babies in non-occupationally exposed pregnant women in Benin City, Nigeria

Abstract

The delivery of babies with low birth weight is a prognosis of neonatal mortality, morbidity and poor health outcomes later in life. This study evaluates the levels of cadmium, zinc and calculated cadmium/zinc ratio in non-occupationally exposed pregnant women at delivery and their relationship with birth weight of babies.

Blood cadmium, plasma zinc and calculated cadmium/zinc ratio were determined in 200 pregnant women at delivery and 100 non-pregnant women which served as controls. Blood cadmium and plasma zinc were assayed by electrothermal Atomic Absorption Spectrometer and spectrophotometric method respectively.

Maternal blood cadmium and cadmium/zinc ratio were significantly higher in those with low birth weight (p<0.001) while plasma zinc was significantly lower than in those who gave birth to babies with normal weight (p<0.001). The anthropometric measurements: birth weight, head circumference and length were significantly lower in babies with low birth weight than in normal birth weight (p<0.05). Blood cadmium and cadmium/zinc ratio correlated inversely with birth weight (r=-0.461; p<0.02) while plasma zinc, head circumference (r=0.392; p<0.05) and length (r=0.390; p<0.05) correlated positively with neonatal birth weight (r=0.482; p<0.02) (r=0.392; p<0.05) (r=0.390; p<0.05) respectively. Concerted effort should be made to check environmental pollutions to avoid their harmful effects on human reproduction and birth weight of neonates.

Keywords: Blood Cadmium, Zinc, Cadmium/Zinc Ratio and Low Birth Weight