Maternal smoking and fetal growth of full term infants.

Abstract

Results of investigation into the effects of maternal smoking and other selected independent variables on fetal growth indicated that smoking by gravida was assoicated with reductions in birth weights and crown-heel lengths, but not with ponderal indices of newborn infants. Mothers of single infants were interviewed following delivery and before discharge about the amount of smoking during pregnancy. Infants were weighed and measured at birth, and step-wise multiple regression analyses were used to interpret the data for 4 groups of infants: males born to primiparas, males born to multiparas, females born to primiparas, and females born to multiparas. Results indicate that maternal smoking during pregnancy was associated with reductions in birth weights and crown-heel lengths, but not in ponderal indices of these groups of full-term infants. The effects of smoking on fetal growth did not appear to be related to poor maternal nutrition, and mean weight gains during the last 2 trimesters of pregnancy were not significantly different in smoking and nonsmoking mothers. Conflicting opinions exist concerning whether the reduction in crown-heel lengths are transitory or not; thus further study is recommended.