These chemicals slow the growth of your baby and increase the chance of ectopic pregnancy, miscarriage, premature birth and stillbirth. Babies born to mothers who smoke are more likely to have a lower birth weight which leaves them more vulnerable to problems in infancy. Low birth weight is the most important reason why babies sometimes die in the first few weeks of life. However if you stop smoking in the first 3 or 4 months of pregnancy, your baby is likely to weigh just as much as a non-smoker's baby. In the first four months of pregnancy the baby is developing all the major organs and is very susceptible to damage from poisons like carbon monoxide in cigarette smoke.
Babies born to mothers who smoke tend to feel less well and to be less contented.
In effect, a smoker's baby starts life by having to give up smoking and this can make them irritable. Babies born to mothers who smoke are more likely to suffer from diseases such as asthma and ear infections in childhood. There is increasing evidence that babies who experienced slow fetal growth are more likely to develop high blood pressure, strokes and heart attacks as adults. By smoking during pregnancy you are putting your baby at risk of illnesses not just in the first few days after birth but probably for the rest of his or her life. Do stop smoking and if your partner smokes, ask your partner to stop, passive smoking is damaging too.