Smoking during pregnancy is a no-no. Previous research has shown that it can harm the baby’s brain, change foetal DNA, and lead to childhood obesity. Earlier studies also found a link between smoking during pregnancy and antisocial behavior in children. However, whether this is a causal relationship remains unclear. In order to gain a better understanding, a team of researchers from Brown University and the University of Maryland looked at 3,443 children of women who took part in the Boston and Providence centers of the Collaborative Perinatal Project (CPP) between 1959 and 1966.
The CPP looked at factors during pregnancy and birth that might influence mental, neurological, and physical capabilities of a child, including smoking habits. The team gathered this data, as well as information from court records on the children between 18 and 33 years of age to assess if any crimes had been committed during this time. The team also interviewed 1684 adults with an average age of 39 whose mothers had taken part in the CPP, asking them about their behaviour as a teen and as an adult.
The behaviour was then compared to diagnostic criteria for conduct disorder in juveniles and antisocial personality disorder in adults. The results showed that 59% of women reported any smoking during pregnancy and many reported smoking heavily, with 33.8% smoking a pack or more per day. The team found that for each pack of cigarettes smoked by the mothers per day, there was an additional 30% increase in the chance of children exhibiting three or more symptoms of conduct disorder as a juvenile and more than three times the chance of showing three or more symptoms of antisocial personality disorder as an adult.
Children of mothers who smoked while pregnant also had more than double the chance of having a record of non-violent offences as a juvenile and of committing a violent offence as an adult. The findings were independent of other factors such as a history of mental illness and low educational attainment/income, leading researchers to suggest that smoking while pregnant may have a small to moderate causal effect on the risk of antisocial behavior in the offspring.
“Many important risk factors for [antisocial behaviour] are not modifiable (eg. sex, family history), but maternal smoking in pregnancy is potentially modifiable, and remains prevalent among particular subgroups of women, including teenage mothers and mothers with less than a high school education,” explained the team.
“Although maternal smoking in pregnancy may result in only slight to moderate increases in an offspring’s risk of antisocial behaviour, removing this exposure may have substantial impacts at the population level.” The findings can be found published online in the Journal of Epidemiology & Community Health.