According to the American Cancer Society, 10 to 16 percent of women smoke throughout their pregnancies, putting themselves and their babies at risk for a number of health issues. In fact, up to 5 percent of infant deaths would be prevented if pregnant women did not smoke.
Smoking affects every phase of reproduction, including fertility, pregnancy complications, premature birth, low-birth-weight infants, stillbirth and infant death, according to the Centers for Disease Control and Prevention.
Pregnancy Complications
Women who smoke are more likely than nonsmokers to develop pregnancy complications, according to the CDC. The risk of placenta previa, a condition where the placenta grows too close to the uterus opening, is about twice as high as in nonsmokers. The risk of placental abruption, a dangerous condition in which the placenta separates prematurely from the wall of the uterus, is 1.4 to 2.4 times that of nonsmokers. The risk of premature rupture of the membranes before labor begins is also higher for smokers.
Premature Birth
The CDC reports that babies of women who smoke during pregnancy are about 30 percent more likely to be born prematurely--before 37 weeks of gestation--than those born to nonsmokers. Premature babies, are at risk for serious health problems during the newborn period, according to the March of Dimes. They are also at risk for lifelong disabilities, including mental retardation, learning problems and cerebral palsy.
Birth Defects
Babies of women who smoke any time during the month before conceiving to the end of the first trimester are more likely to have birth defects, especially heart defects, according to the March of Dimes. The risk of heart defects appears to increase with the number of cigarettes a woman smokes.
Low Birth Weight
Low birth weight is a leading cause of infant deaths, resulting in more than 300,000 deaths in the United States every year. Smoking during pregnancy slows the growth of the fetus, causing at least one in five infants to be born weighing less than 5.5 pounds or 2,500 grams, according to the American Cancer Society. The more a pregnant woman smokes, the greater her risk of having a low-birth-weight baby.
Sudden Infant Death Syndrome
Infants of mothers who smoke during and after pregnancy are three to four times more likely to die from sudden infant death syndrome than babies born to nonsmoking mothers, according to the American Cancer Society. The risk of SIDS is somewhat less for infants whose mothers stop smoking during pregnancy, even if they start smoking again after delivery.
Strabismus (Cross-Eyes)
Exposure in the uterus to harmful substances, including tobacco, affects the developing brain of the fetus. The National Institutes of Health reports that each cigarette smoked by a pregnant woman raises her baby's risk of strabismus--being cross-eyed--by 5 percent. Smoking 10 or more cigarettes a day is associated with a 90 percent greater risk of developing strabismus.
References
- Centers for Disease Control and Prevention: Tobacco Use and Pregnancy
- National Institutes of Health: Smoking in Pregnancy May Up Risk of Cross-Eyed Baby
- Centers for Disease Control and Prevention: Highlights: Smoking Among Adults in the United States: Reproductive Health
- March of Dimes: Smoking During Pregnancy
