Smoking risk to babies

Middle-class women who smoke while pregnant do little harm to their unborn babies. Smokers from poorer backgrounds do risk damage to their children, but only because they combine cigarettes with alcohol and a poor diet.

Emma Tominey, from the London School of Economics, studied data on 3,368 mothers and 6,860 children taken between 1973 and 2000. Smoking during pregnancy reduced birth weight by 5.6%, but when adjusted for other factors it accounted for just 1.8%.