Research has indicated that people who smoke have an increased chance of a miscarriage, because of the harmful substances in cigarettes. These substances cause a less good attachment of the placenta, which is necessary for the supply of oxygen to the child. Due to this, there is a risk that the baby grows less well. Children of smokers often have a (too) low birthweight and are often born prematurely. This can make them more vulnerable. During the first years of life they have problems with their airways more often. There are indications of cot death occurring more often if there is smoking near the baby. This is why the advice for both parents is: stop smoking and avoid smoky areas as much as possible. It’s wise to stop the moment you and your partner want to have children.
You can find more information about smoking here.