Spontaneous Abortion as Risk Indicator in Metal Exposure

Abstract

We have used a nation-wide hospital discharge register to retrieve cases of spontaneous abortion. The frequency of hospitalized spontaneous abortions has been studied in relation to occupational factors. Three study schemes are presented in the application of the spontaneous abortion register in relation to metal work and exposure to metals. Scheme 1 involved a study on the female members of the Union of Metal Workers covering years 1973 – 1979. Eleven hundred spontaneous abortions were recorded for the women. The age-standardized frequency of spontaneous abortions in relation to pregnancies was slightly higher (7.8 percent) for the pregnancies conceived during Union membership, as compared with those (7.1 percent) conceived before or after it. Exposure to sulfur, zinc, cobalt and arsenic was considered possible for workers of a metallurgical plant. Seven spontaneous abortions were recorded, giving a frequency of 21 percent of all pregnancies. Scheme 2 involved analysis of occupations of women and their husbands in a community with metallurgical industry. The rate of spontaneous abortions was higher for all economically active women as compared with all the women in the community. The wives of industrial workers did not deviate from all the women in the community in the rate of spontaneous abortions. The wives of the workers employed at the metallurgical factory had somewhat more spontaneous abortions than the wives of all industrial workers. In scheme 3, the frequency of spontaneous abortions was analysed in relation to the occupation of the woman and her husband as stated in the census taken at the end of 1975. One group of female metal workers (welders) had an abortion rate of 9.5 percent as compared with 8.2 percent for all industrial workers.