Urinary nickel concentrations and selected pregnancy outcomes in delivering women and their newborns among arctic populations of Norway and Russia

The two objectives of this study were to compare urinary nickel excretion i n pregnant women and their newborns living in the Murmansk and Arkhangelsk Counties of Russia with that in comparable Norwegian populations living in Finnmark and the city of Bergen and to assess the influence on pregnancy ou tcome of different risk variables, specifically urinary nickel concentratio ns and questionnaire-based anamnestic information. Life-style information a nd urine samples were collected from 50 consecutive mother-infant pairs fro m hospital delivery departments in three Russian and three Norwegian commun ities. Pregnancy outcomes were verified from medical records. Urinary nicke l excretion was significantly higher in the Russian communities, independen t of the presence of a nickel refinery as a local environmental source. The birth weight and mean body mass index of the newborn children (BMIC) were significantly lower (p < 0.001) in the Russian groups, with or without adju stment for gestational age. A multivariate linear regression analysis indic ated that maternal urinary nickel concentration had no impact on birth weig ht. The maternal body mass index (BMI) and maternal height were positive ex planatory variables, maternal urinary creatinine is suggested as a weak neg ative factor. Smoking was shown to be a strong negative predictor only in t he Norwegian group among whom there was a significantly higher smoking freq uency (p= 0.005). The significant contribution of a country factor in the p redictive model is interpreted to indicate that a number of important risk factors for low birth weight were not identified.