Women who smoke during pregnancy are more likely to give birth to babies with behavioral problems, according to a study reported in the current issue of the Journal of Epidemiology and Community Health. The study included 18,000 UK babies born between 2000 and 2002.

The mothers were classified as either non-smokers during pregnancy, quitters, light smokers and those who smoked 10 or more cigarettes a day (heavy smokers). The infants’ temperaments were assessed when they were 9 months old. The results showed that mothers to be who kicked their habit had the most easy-going infants. At the other end of the scale, heavy smokers had the most difficult children. Their babies were much more likely to exhibit negative behavior traits.
Several studies conducted by the March of Dimes have shown that that babies of mothers who smoke during pregnancy undergo withdrawal-like symptoms similar to those seen in babies of mothers who use some illicit drugs. For example, babies of smokers appear to be more jittery and difficult to soothe than babies of nonsmokers. Babies whose mothers smoked during pregnancy are up to three times as likely to die from sudden infant death syndrome (SIDS) as babies of nonsmokers.
Cigarette smoke contains more than 2,500 chemicals. It is not known for certain which of these chemicals are harmful to the developing baby, but both nicotine and carbon monoxide play a role in causing adverse pregnancy outcomes. Studies suggest that babies of women who are regularly exposed to secondhand smoke during pregnancy may have reduced growth and may be more likely to be born with low birth weight. Pregnant women should also avoid exposure to other people’s smoke.

Source: British Medical Journal