Effect of Mothers' Smoking Habits on Birth Weight of their Children

It has been reported that when pregnant rats and rabbits are exposed to tobacco smoke their offspring weigh less than those of control animals (Essenberg, Schwind, and Patras, 1940; Schoeneck, 1941). A similar observation has been made in respect of pregnant women. Simpson (1957) collected data over a three-year period from American maternity hospitals and found that the incidence of premature births (those weighing 5½ 1b.— 2.5 kg.—or less) among women who smoked was double that among non-smokers and increased fairly regularly with the amount smoked. No explanation was offered for this observation, but it is clear from the data that age, parity, and social circumstances had little to do with it.