Spontaneous abortions were analyzed in an industrialized Finnish community according to the occupation and workplace of both the women and their husbands. Information about spontaneous abortions and births was obtained from the hospital discharge register, and data about the women and their families were collected from census files. When compared with all women employed outside the home, women who worked at a textile plant (factory A, a clothing manufacturer) had an increased rate of spontaneous abortion (16.7 per cent vs 11.4 per cent). The rate of spontaneous abortions among women employed at factory A differed according to the husband's workplace. The odds ratio for women employed at factor A whose husbands worked at a large metallurgical factory was 3.8, whereas the odds ratio for women whose husbands worked elsewhere was 1.2. Between 1973 and 1976, the rate of spontaneous abortions in this town was consistently lower for the summer period. (May-August) than for the other periods of the year.
PIP: The effects of occupational and other environmental factors of the frequency of spontaneous abortions was studied in a single Finnish community, Kokkola, a town with over 30,000 inhabitants. The frequency of hospitalized spontaneous abortion in Kokkola and in the surrounding area exceeds that of other parts of Finland. The metallurgical industry of Kokkola emits cadmium and other heavy metals and a sulfur factor discharged sulfur dioxide into the air until shut down in 1977. From the computerized hospital discharge registry maintained by the Finnish National Board of Health, information was obtained on all women for Kokkola who had been treated for spontaneous abortion (diagnoses numbers 643 and 645), for induced abortion (diagnoses numbers 640-642), or who gave birth (diagnoses 650-662) between 1974-77. A patient was only included once if she had been discharged from hospital twice within 4 months with any diagnosis used. The data comprised 3216 pregnancies, 2377 of which were births. Because of underreporting, the births covered 94% of all the officially recorded births in Kokkola between 1974-77. Increasing parity increased the risk of spontaneous abortion only among those under age 25 (with relatively few pregnancies for the 2 and 3+ parity data points). There were seasonal changes in the rates of spontaneous abortion. The rates were calculated per pregnancies that had started 3 months earlier. The rates were 3-7 percentage units above average in March and April and dropped in June and July by 3-4 percentage units below average. These changes were constant for the 3 years studied. The rates and ratios of spontaneous abortion were investigated according to the occupation of both the women and their husbands. The rate for all the women of Kokkola was 9.5% and the ratio was 12.9% Industrial workers had the highest rate (12.2%), but their rate failed to differ significantly from the rate for all economically active (working) women. The rate and ratio of spontaneous abortion for working women were significantly higher than the respective rate and ratio of economically active women. Women working in industry were hospitalized because of spontaneous abortion more often than other women in the community. No such clear occupational correlations were found for the paternal occupation if it was analyzed without consideration of the maternal occupation. When compared with all women employed outside the home, women who worked at a textile plant (factory A, a clothing manufacturer) had an increased rate of spontaneous abortion (16.7% vs 11.4%). The odds ratio for women who worked at factory A whose husbands worked at a large metallurgical factory was 3.8; the odds ratio for husbands who worked elsewhere was 1.2.