Spontaneous abortions among nickel-exposed female refinery workers

A case-control study to investigate whether women employed in nickel-exposed work areas in early pregnancy are at elevated risk of spontaneous abortion (SA). Data about pregnancy outcome and maternal factors were obtained about each delivery and SA from women in selected work places. Each pregnancy record was assigned a categorical nickel (Ni) exposure rating according to the women's occupations at pregnancy onset. The guidelines were the …