Effect of lead on fetal growth in a Canadian smelter city, 1961-1990.

The fetuses of women who live adjacent to a large lead smelter may experience intrauterine growth retardation that results from the mothers' systemic availability of lead absorbed from their environment. In this study, the authors used 30 y of birth records (n = 9329) to obtain fetal growth measurements for the smelter city and a suitable control city. The authors determined rates of intrauterine growth retardation (small-for-date births) for 5-y periods, and they determined the estimated relative risk of intrauterine growth retardation that occurred in the smelter city and compared it with the control city. The risk of intrauterine growth retardation for women in the smelter city was not significantly greater (odds ratio = 0.83) for either the 30-y period or each of the 5-y periods (odds ratio range = 0.51-1.33). The authors concluded that fetal growth was not affected by the amount of lead absorbed by women who lived in a smelter environment.