Women who smoke during pregnancy are much more likely to experience the nightmare of having a stillborn baby, to suffer a miscarriage, or to deliver a low birth-weight baby. Sudden Infant Death Syndrome (or SIDS, for short), condition in which an apparently healthy baby dies unexpectedly during sleep, occurs twice as often in children born to mothers who smoke during pregnancy.

Cigarette smoking can increase the risk of a wide variety of pregnancy complications including premature rupture of membranes, vaginal bleeding and premature placental detachment- just to name a few. Smoking interferes with your absorption of vitamins B and C and folic acid. Lack of folic acid can result in neural tube defects.

The thousands of chemicals in cigarette smoke (including secondhand smoke) such as carbon monoxide and nicotine, are toxins that move through your bloodstream and harm your developing baby. When you smoke, your baby is confined in a smoke-filled womb and this reduces the flow of oxygen to your baby. The nicotine can cause your baby's heart rate to increase (as well as yours) and can decrease your baby's supply of nutrients because of your increased blood pressure and blood vessel constriction.

Smoking in the First Trimester

For some women, quitting will never be easier than in early pregnancy when they develop a sudden distaste for cigarettes. If you stop smoking now, you can decrease your chances of miscarrying and it may also lessen the likeliness of affecting your baby's development. It is best to stop smoking before you become pregnant, but stopping now is a very smart choice and your odds of having a healthy baby are good.

Smoking in the Second Trimester

If you quit smoking now, you can decrease your chances of developing such complications as placenta previa going into pre-term labor and even stillbirth. If you tried to quit smoking in your first trimester, but didn't succeed- at least for the sake of your baby- cut down on how many cigarettes you smoke each day. Every cigarette you don't smoke is going to help your baby.

Smoking in the Third Trimester

It is not too late to quit smoking. If you stop now, you can still improve your chances of delivering a healthy, full-term, normal birth-weight baby. Decreased birth-weight is directly related to the number of cigarettes you smoke. There is a direct relationship between smoking and impaired fetal growth. By quitting now, you can also better your odds of not loosing your baby to SIDS. Sooner is better, but quitting even in the last month can help preserve oxygen flow to your baby during delivery.