Effect of mothers' smoking habits on birth weight of their children

Abstract

Obstetrical and smoking histories were recorded for 2,042 pregnant women delivered in six Birmingham maternity hospitals during the summer of 1958. The mean weight of infants of mothers who smoked regularly throughout pregnancy was 6 oz. (170 g.) less than that of infants of mothers who never smoked during pregnancy (6.93 lb. and 7.33 lb. respectively). This was more than the difference in weight between male and female infants and between first and later births. It was sufficient to lower significantly the incidence of surgical induction among smokers. The effect of smoking upon birth weight was unrelated to maternal weight, age, and parity, or to the complications of pregnancy. It was not due to shortening gestation (brought about by early onset of labour). It is concluded, therefore, that smoking during pregnancy substantially retards foetal growth. © 1959, British Medical Journal Publishing Group. All rights reserved.