EFFECT MEASURES FOR BEHAVIORAL-FACTORS ADVERSELY AFFECTING FETAL GROWTH

The purpose of this study was to estimate the proportion of ultrasonic ally diagnosed fetal growth retardation that may be attributable to po tentially remediable behavioral factors (for example, cigarette smokin g, alcohol use, and drug addiction). We computed multivariate odds rat ios for fetal growth retardation associated with cigarette smoking and alcohol and illicit drug consumption in 350 singleton pregnancies com plicated by fetal growth retardation and 700 controls. The odds ratio of fetal growth retardation among women who smoked throughout pregnanc y was 2.61 (95% confidence interval, 1.38 to 4.93) compared to women w ho claimed to have stopped smoking by the 18th week of gestation. The summary attributable risk of fetal growth retardation associated with behavioral variables measured during the first trimester and thereafte r ranged from 18 to 21%. BY implication, the maximum proportion of fet al growth retardation that could theoretically be prevented by elimina ting these risk factors accounts for about 1% of all births. However, allowance for the limited modifiability of preventable factors and the consistent overlap between them would probably reduce such estimate t o less than 1%. We conclude that only interventions to reduce the prev alence of strong risk factors (for example, preeclampsia, sociodemogra phic variables) may have a substantial effect on the incidence of impa ired fetal growth and subsequent infant morbidity.