Effects of Cigarette-Smoking on the Fetus and Child

Abstract

For the Health of Our Children, Please Don9t Smoke was the message on a sign sent recently by the American Academy of Pediatrics to its members to be posted in their waiting-rooms (Fig. 1). Cigarette-smoking by the mother during pregnancy can affect the fetus, and smoking by either parent in the presence of the child may affect his health. BIRTHWEIGHT AND FETAL BREATHING MOVEMENTS Many studies have now shown that if the mother smokes during pregnancy the birthweight of the infant is reduced, on the average, by about 200 gm. 1,2 Yerushalmy protested that the effect was due not to smoking but to constitutional differences in smokers as compared with nonsmokers. 3-6 Since Yerushalmy9s death, his argument has been continued by Burch 7,8 and Hickey et al. 9 in a debate with Goldstein. 10-12 Astrup et al. 13 in Denmark had attempted to resolve the matter in a study which showed that carboxyhemoglobin levels from carbon monoxide exposure of rabbits and from cigarette-smoking in pregnant women were both correlated with reduction in the birthweight of the offspring. This seeming support form animal experimentation and from human laboratory observations did not satisfy Hickey et al. 14 who claimed that some smokers may, in using tobacco, compensate for a deficiency in biogenic amine physiology–and the carboxyhemoglobin may, for genetic reasons, be more slowly cleared from the blood by smokers than by non-smokers. Hence innate differences in the mothers might account for the correlation between blood levels and birthweight. This rationale seems strained, especially when one considers that the effect, observed in many different races, cultures and geographic areas, is dose-related, independent of factors known or suspected to influence birthweight, corrected within six months by accelerated growth rate (as if a toxic influence had been removed), and not found if the mother gives up smoking before the start of her pregnancy.