Maternal nickel exposure and congenital musculoskeletal defects.

OBJECTIVE: To investigate whether women occupationally exposed to nickel in early pregnancy are at elevated risk of delivering a newborn with a malformation or deformation of the musculoskeletal system (ICD-10: Q65-Q79). METHODS: Data about the newborn, maternal occupation and workplace were obtained using the Kola Birth Register (KBR). Each record in the KBR was assigned a categorical nickel (Ni) exposure rating according to the occupation the delivering woman had at the time of becoming pregnant. This was achieved by using as a guideline the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The reference population was delivering women from the source population with background exposure level. In total, the study population consisted of 22,965 births. RESULTS: Three hundred and four infants (13.3/1,000 births; 95% confidence interval (CI): 11.9-14.7) were diagnosed with isolated musculoskeletal defect(s) at birth. The adjusted odds ratio for the association between the maternal exposure to Ni and this outcome was 0.96 (95% CI: 0.76-1.21) per unit increase in exposure category. CONCLUSION: The incidence of defects in the musculoskeletal system at birth was high, especially for feet deformities, but we found no effect of maternal exposure to water-soluble Ni on the risk of delivering a newborn with a defect. However, the incidence among women working in the copper refinery was higher than in the other employment groups.

The prevalence of selected pregnancy outcome risk factors in the life-style and medical history of the delivering population in north-western Russia.

OBJECTIVES: A population-based birth registry has been set up for the Arctic town of Moncegorsk in north-western Russia. This investigation describes the health status of the delivering population, including pregnancy history and the prevalence of obesity, infections, smoking and alcohol abuse during the pregnancy period. An overview of the occupations of the delivering population is also presented. METHODS: The birth registry contains detailed and verified information about the newborn, delivery, pregnancy and the mother for 21,214 births by women from Moncegorsk in the period 1973-97. RESULTS: Of the delivering women, 15.7% had experienced one or more spontaneous abortions, and 47.4% had at least one induced abortion. More than 9% had suffered pelvic inflammatory disease (PID) in their past. The local nickel company employed 9016 (42.5%) of the delivering women; of these 17% worked in production areas with exposures to compounds of nickel, among other hazards, and 38% are judged to have had possible, or probable, exposure of this type. CONCLUSION: Compared with the delivering population in Norway, that in Moncegorsk was younger and had a lower prevalence of obesity, diabetes and heavy smoking. The most worrisome findings were the high prevalence of a history of abortion and PID. A relatively high proportion of the women worked in physically demanding, or/and nickel-exposed occupations.