A Cardiff University research project has for the first time studied whether smoking during pregnancy can directly make children more likely to behave anti-socially.
The unique study by scientists at the University's Schools of Medicine and Psychology examined the records of 779 children born by in-vitro fertilisation (IVF) whose prenatal environment was provided by either a related mother or an unrelated mother. They found a link between anti-social behaviour in children whose mothers smoked in pregnancy – but only when the mother was genetically linked to the child.
When the child came from a donated egg and donated embryo – egg or embryo donation or surrogacy - there was no link, suggesting factors other than smoking during pregnancy influence anti-social behaviour.
The results of the study, funded by the Wellcome Trust, are published today (Tuesday 3 February 2009) in Proceedings of the National Academy of Sciences .
It is well-established that smoking during pregnancy, whether the mother is genetically related to the baby or not has an adverse effect on birth weight. However, links between what mothers do in pregnancy and how it may affect the mental health and behaviour of children are less researched. While mothers who smoke during pregnancy are more likely to have anti-social children, it has not been clear if this is a direct result of the smoking. The Cardiff University researchers were able to study IVF children, with differing degrees of genetic relation to their parents, to disentangle the effects of genetic influences and the prenatal environment.
The study is the first study of its kind in the world to allow these effects to be separated. In the published paper, the researchers looked at effects of mother's smoking in pregnancy on the child's birth weight and the child's behaviour, paying particular attention to mothers not genetically related to their unborn baby.