Video display terminals and the risk of spontaneous abortion

The relationship between the electromagnetic fields emitted by video display terminals (VDTs) and spontaneous abortion (miscarriage) has been a public health concern for over a decade. Extremely-low-frequency fields have been implicated in seasonal spontaneous abortions among those who used electric blankets or ceiling-cable electric heat. Studies of very-low-frequency electromagnetic fields and spontaneous abortion have concentrated on the effects of VDTs. Full-time female telephone operators, half of whom were directory-assistance operators who used VDTs, and half who were general operators who did not use them were surveyed to determine the effects of working at VDTs. Eight hundred eighty-two pregnancies (in 730 women) met the criteria of the study. There was no increase in the risk of spontaneous abortion among those women who used VDTs. Although statistically a moderate increase could not be ruled out, various other measures of risk make an association unlikely. Spontaneous abortion was more frequent among those who drank alcohol heavily, smoked cigarettes, or had a thyroid disorder. There were no differences in VDT use outside the workplace that could have influenced the results. There was no way to measure very early (subclinical) fetal loss in this study, nor was the effect of VDT use on older women (over 33 years of age) or unmarried women measured, and these women are in the majority in the population. The study found that abdominal exposure to extremely-low-frequency fields was similar to exposure found in the home, and there was no evidence of an increased risk. (Consumer Summary produced by Reliance Medical Information, Inc.)