[The effect of mothers' occupation on body mass of newborns born at term].

The body mass is one of the major indicators which determine the clinical condition of newborns, influence the rate of neonatal mortality and further development of newborns. In order to prevent malformations it is necessary to identify factors which impair the fetus development and cause fetal hypotrophy. The main objective of the study was to find out whether mothers' occupational work affected the body mass of infants born at term. The study covered a group of 1015 women randomly sampled among those who had delivered their babies in the Polish Mother Memorial Hospital in Lódź, during the years 1992-94. In this group the percentage of working women accounted for 69%. The comparison of the body mass in infants born to women employed and not employed during pregnancy did not indicate differences. However, it was found that male infants born to employed mothers showed a lower body mass than those born to not employed mothers. The effect of some factors modifying infants' body mass was different in the case of not employed women than in those employed. In the group of not employed women a significantly lower body mass in infants was observed in the following subgroups: mothers under 24 years of age, spontaneous abortion of one of previous pregnancies, consumption of large quantity of caffeine (equivalent of > two cups of coffee), and poor economic status. Smoking during pregnancy decreased the body mass of infants in both groups of women. In the group of working women, chronic diseases before pregnancy and diseases involving fever during pregnancy proved to be factors affecting the body mass of infants. The indicators of perinatal medical care (the beginning of medical care and the number of visits during pregnancy) in working women were better than in those not working. None of factors characterizing occupational work affected significantly the body mass of infants. Slightly lower infants' body mass was observed only in those born to mothers working overtime (> 9 hrs daily), involved in hard physical work or working in the environment with harmful chemical and physical factors. According to the data obtained, a negative effect of occupational work on the fetus development should not be overestimated. Nevertheless, the performance of occupational work may aggravate a negative effect of woman's bad health condition on the fetus development.