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Biomedical subjects

K Rantala

Publications and source records attributed to K Rantala.

7 recordsLinked to original sources

Effects of paternal occupational exposure on spontaneous abortions.

BACKGROUND: Paternal exposure to mutagenic agents has been suggested to affect pregnancy outcome adversely. METHODS: A nationwide data base of medically diagnosed spontaneous abortions and other pregnancies and national census data was used to evaluate the effects of men's occupational exposures on risk of spontaneous abortion in 99,186 pregnancies in Finland. Census data from the years 1975 and 1980 provided information about the occupation, industry, and socioeconomic status. A job-exposure classification was developed to classify women and their husbands according to possible occupational exposures on the basis of their occupational title and industry. RESULTS: In 10% of the pregnancies, the husband was exposed to one or more of the mutagens, and the rate of spontaneous abortion was unaffected (OR = 1.0). Of the 25 specific mutagenic exposures evaluated, paternal exposure to four (ethylene oxide, rubber chemicals, solvents used in refineries, and solvents used in the manufacturing of rubber products) was associated with an increased relative risk of spontaneous abortion. In addition, the risk of spontaneous abortion was higher among wives of rubber products workers than among unexposed men. CONCLUSIONS: Although there is some biological rationale for the findings of this study, these findings need to be confirmed by studies in which individual exposures can be measured directly.

Abortion, Spontaneous

Cardiovascular malformations and maternal exposure to video display terminals during pregnancy.

The possible effects of working with video display terminals (VDTs) during pregnancy on the occurrence of cardiovascular malformations in the offspring was studied in 500 cases and 1055 controls. The cases represented all registered cardiovascular malformations reported in Finland during 1982-84, excluding those with chromosomal anomaly or known genetic syndrome. The controls were randomly selected from all babies born during the same period. Both the case and control mothers were interviewed by midwives using a structured questionnaire approximately three months after delivery. In this interview the mother's occupation, job description and employer during the first trimester were noted, as were large number of other exposures to chemical and physical factors. An industrial hygienist examined all these records for information indicating exposure to VDTs, unaware of case/control status. Work with VDTs during the first trimester of pregnancy was ascertained for 30 case mothers (6.0%, 30/500) and 53 control mothers (5.0%, 53/1055). In logistic regression analysis maternal exposure to VDTs for at least 20h a week during the first trimester of pregnancy showed a point estimate of odds ratio of 1.4 with 95% confidence limits of 0.5 and 3.8, when adjusted for age and alcohol use. Maternal exposure to VDTs was not associated with indicators of fetal growth such as birthweight, placental weight or length of gestation.

Computer Systems

Noise exposure during pregnancy and selected structural malformations in infants.

The study tested the hypothesis of exposure to noise during pregnancy being teratogenic. It included 1,475 Finnish mothers who had given birth to a malformed child (orofacial cleft or structural defect of the central nervous system, skeleton, or heart and great vessels) and 1,475 reference mothers. A special interview soon after delivery yielded the primary information on exposure. Of the 783 mothers who reported noise exposure in the first trimester, 370 were case mothers and 413 were referents. Hygienic assessment indicated that 102 case mothers and 103 referents had been exposed in the first trimester to a sound level of around 80 dB LAeq(8 h) or higher, the overall odds ratio being 1.0 (95% confidence interval 0.7-1.3). Adjustment for potential confounders by logistic regression methods gave similar results. There was no obvious trend suggesting a hazard when different exposure categories were considered.

Congenital Abnormalities

Cardiovascular malformations, work attendance, and occupational exposures during pregnancy in Finland.

To explore for associations between occupational factors and cardiovascular malformations, information on the parents of 160 infants with cardiovascular malformations and 160 control parents was studied. The case infants had been reported consecutively to the Finnish Register of Congenital Malformations. All mothers were interviewed identically after delivery, using both open and pro forma questions about detailed work tasks, exposures, and leisure activities during pregnancy. The interview information was evaluated blindly. Neither parental occupational titles nor maternal working per se gave new clues to the teratogenic risk; nor did shift working, wearing of personal protective equipment, or the mother's own opinion on exposures during pregnancy. Identified occupational exposures, as categorized by an industrial hygienist, showed no remarkable associations to cardiovascular malformations. Few mothers were exposed substantially to specific occupational hazards. Comparing mothers who used medications in the first trimester with those who did not showed an odds ratio of 2.2 (95% confidence interval 1.3-3.9) when adjusted for potential confounding by multivariate logistic methods.

Abnormalities, Drug-Induced

Birth defects and exposure to video display terminals during pregnancy. A Finnish case-referent study.

In a test of the widely publicized allegation that exposure to video display terminals causes birth defects, interview forms of mothers of 1 475 children reported consecutively to the Finnish Register of Congenital Malformations to have defects of the central nervous system, orofacial clefts, skeletal defects, or cardiovascular malformations and the forms of the same number of their paired referents were studied. The scrutiny revealed 490 mothers with occupational titles indicating potential exposure to video display terminals. Of the 490, 235 were case mothers and 255 were referents. Then, unaware of the case-referent status, three members of the research team perused the mothers' interview descriptions of workday activities for information indicating exposure to video display terminals. Work with such terminals during the first trimester of pregnancy was ascertained for 111 mothers. Of these, 51 were case mothers and 60 were referents. The comparison of the mothers exposed to video display terminals during the first trimester with those not exposed at all showed a crude odds-ratio point estimate of 0.9 with 95% confidence limits of 0.6 and 1.2. Adjustment for potential confounders by multivariate logistic regression methods did not materially affect the risk estimates. The results did not indicate a teratogenic risk for operators of video display terminals.

Adult