Association between prenatal nickel exposure and preterm low birth weight: possible effect of selenium.

There is a proposed link between prenatal nickel (Ni) exposure and preterm low birth weight (PLBW); however, this association remains unclear. Selenium (Se) may modify this relationship by protecting against Ni toxicity. Concentrations of Ni and Se were measured in urine samples collected from 408 pregnant women (102 PLBW cases and 306 matched controls) in China. Conditional logistic regression was utilized to explore the association between Ni levels and PLBW, as well as the effect modification by Se on this association. A significant association was observed between higher maternal urinary Ni levels and risk of PLBW [adjusted odds ratio (OR) = 2.80 (95% confidence interval (CI): 1.44, 5.44) for the highest tertile], and this association was more apparent among female infants than that among male infants. Further analyses showed that mothers with high urinary Ni and low urinary Se levels had a significantly increased risk for PLBW [adjusted OR = 2.87 (95% CI: 1.09, 7.56)] compared with the mothers with low urinary Ni and high urinary Se levels. Our study indicates that prenatal exposure to Ni was a risk factor for PLBW. Se might provide protection against the toxicity of Ni.