Smoking cessation in pregnancy.

More than 400,000 deaths occur per year in the United States that are attributable to cigarette smoking; the risks to the general public are widely known. The risk to women, especially those who are pregnant, is less commonly known. During pregnancy, smoking increases the risk of low birth weight infants, placental problems (previa and/or abruption), chronic hypertensive disorders, and fetal death. It is proposed that much of this happens because of vasoconstriction with decreased uterine blood flow from nicotine, carbon monoxide toxicity, and increased cyanide production. Infants of smoking mothers have increased risks, such as sudden infant death syndrome.