Abstract
Extract: Maternal smoking during pregnancy was associated with reductions in birth weights and crown-heel lengths, but not in ponderal indices of four groups of full term infants. The reductions in crown-heel lengths were statistically significant in three of the four groups of infants. The effects of smoking on fetal growth did not appear to be related to poor maternal nutrition. Mean weight gains during the last two trimesters of pregnancy were not significantly different in smoking and nonsmoking mothers and were above the mean weight gains recommended by the National Research Council.
Speculation: The effects of smoking and poor maternal nutrition, as measured by low weight gains during the last two trimesters of pregnancy, are about the same with respect to linear growth of the fetal skeleton, but differ with respect to ponderal indices. Ponderal indices are not affected by smoking but tend to be markedly reduced if maternal weight gains during pregnancy are low.