Even using nicotine substitutes is bad for the baby
Going cold turkey from smoking whilst pregnant is proven to be the only way to protect your unborn child.
Babies whose mums smoke or even use nicotine patched or chew gum, while pregnant are more likely to have high blood pressure in later life.
The addictive substance is absorbed by the foetus which can lead to heart problems in later life.
The research carried out in America, suspects that the nicotine causes harmful chemicals to form in the babies blood vessels which leads to them not being able to function properly.
More than a quarter of mothers in Britain either smoked during pregnancy or gave up as soom as they found out they were expecting, according to NHS research - the exact numbers are unknown of those who use the patches or the gum.
Doctors advise pregnant women who need some form of nicotine therapy are advised to chew gum rather than patches as they are less strong.
Femalefirst Taryn Davies