Smoking while pregnant puts both mother's and baby's life at risk. Currently, about 13 percent of pregnant women in the U.S. smoke during pregnancy. If all pregnant women stopped smoking while pregnant, there would be an estimated 10 percent reduction in infant deaths in this country, according to the U.S. Public Health Service. Smoking while pregnant should be a cause for concern. Cigarette smoke contains more than 2,500 chemicals, with nicotine, tar, and carbon monoxide thought to be the most dangerous to the fetus.

The sooner a mother quits smoking, the better it will be for both her and her baby. If you currently smoke, it's not to late to do something about it. Quitting during the first trimester can greatly reduce the risk of having a baby with low birth weight — almost to that of a woman who doesn't smoke. The fewer cigarettes a woman smokes, the less likely her baby will be born with smoking-related problems.

Tell your doctor if you need help quitting. If you are a heavy smoker and have not been able to quit or cut down, you may be able to use a nicotine patch to help you quit while you are still pregnant. There are risks to using the patch during pregnancy, but the risk of heavy smoking may be greater.

Even if you don't smoke, be aware that your baby can be harmed by people smoking around you. Pregnant women regularly exposed to other people's smoke during pregnancy may also be at increased risk of many of the same fetal development problems.

Smoking During Pregnancy: Complications
Smoking has been associated with a number of pregnancy complications. One is an increased risk of ectopic pregnancy. In an ectopic pregnancy, the embryo becomes implanted in a fallopian tube or other abnormal site instead of the uterus. With the rarest of exceptions, these pregnancies do not result in the birth of a baby, and must be removed surgically or with drug treatment to protect a woman's life.

Cigarette smoking also appears to double a woman's risk of developing placental complications (which occur in about 1 percent of pregnancies). These include placenta previa, a condition in which the placenta is attached too low in the uterus and covers part or all of the cervix; and placental abruption, in which the placenta separates from the uterine wall before delivery. Both can result in a delivery that jeopardizes the life of mother and baby.

Smoking during pregnancy also increases the risk of stillbirth, miscarriage, and severe vaginal bleeding.

Smoking During Pregnancy: Risks to Your Baby
Smoking during pregnancy, which can seriously slow fetal growth, nearly doubles a woman's risk of having a baby with low birth weight. In 1998, 12 percent of babies born to smokers in the U.S. were of low birth weight, compared to 7.2 percent of babies of nonsmokers.