Smoking in late pregnancy is linked to lower IQ in offspring

Mothers who smoke in late pregnancy risk having children with lower intelligence. Young men whose mothers smoked 20 or more cigarettes a day had IQs that were on average 6.2 points below those of sons of non-smokers, research has found (Paediatric and Perinatal Epidemiology 2005;19:4-11).

The more cigarettes a woman smoked, the greater the risk. The association was as strong in children with high social status as in low status offspring.

“Our results reveal significant long term effects of maternal smoking …