Smoking and Pregnancy

In 2002, 17.3 percent of pregnant women aged 15 to 44 smoked cigarettes in the past month compared with 31.1 percent of nonpregnant women of the same age group. Though the rates are lower in pregnant women when compared to nonpregnant women in the same age group, it should be noted that this is a very high prevalence rate because of the additional health hazards for mother and baby.

When a pregnant woman inhales tobacco smoke, the carbon monoxide and high doses of nicotine interfere with oxygen supply to the fetus. Nicotine concentrations in the fetus can be as much as 15 percent higher than maternal levels. It appears that nicotine is concentrated in fetal blood, amniotic fluid and breast milk. These factors can cause developmental delays in the fetuses and infants of smoking mothers.

Other risks associated with smoking during pregnancy include:

• Women who smoke during pregnancy are at greater risk for premature delivery.

• Smoking during pregnancy can also lead to sudden infant death syndrome and small- birth-weight babies. The more a woman smokes during pregnancy, the greater the reduction of infant birth weight.

• Women who smoke during pregnancy and while their babies are infants predispose their children to long-term pulmonary risks.

• Many researchers believe that smoking during pregnancy causes attention-deficit/hyperactivity disorder and other learning disorders in children.

• Researchers have found that children whose mothers smoked during their second and third trimesters had demonstrated poorer attention skills than other children.

By Drew Edwards, MS; Mark S. Gold, MD
© 1999 University of Florida McKnight Brain Institute