Maternal smoking: greater effect on males, fetal tobacco syndrome?

We tested the recently proposed criteria for a Fetal Tobacco Syndrome (FTS) on a sample of 925 primiparous black women (including 204 smokers) and their neonates. The proposed FTS criteria included proportional growth retardation (ponderal index greater than 2.26, birth weight less than 2,500 g) in term neonates. Only 19 neonates (2%) in our study fulfilled the FTS morphometric criteria, and of these only 8 had smoking mothers. Nonetheless, the negative effect of maternal smoking on fetal growth (birth weight and length) as reported from earlier investigations was clearly evident in our own data (P less than .01). Separate analysis by fetal sex revealed that the negative effect of maternal smoking upon fetal growth is more pronounced among males than females. We concluded that fetal sex should be taken into account in studies of maternal smoking effects. As for evidence for the existence of the FTS, it remains to be proven.