Whether or not expecting mothers are active tobacco users, secondhand smoke can affect their fetuses in many ways. The U.S. Department of Health and Human Services reports that nonsmoking women can inhale airborne smoke passively, or secondhand. They can also contact tobacco residue in the particles on a smoker's clothing, or in the dust of a smoker's environment. Women who smoke have a harder time conceiving and delivering babies. Pregnant women who smoke may suffer reproductive health problems themselves or create difficult birth situations for their developing babies.
Poor Circulation
Secondhand smoke crosses the placenta via the bloodstream to affect the fetus. The nicotine in cigarette smoke increases the baby's heart rate. The carbon monoxide in smoke displaces oxygen in the blood. The Centers for Disease Control and Prevention (CDC) reports that this can decrease the amount of oxygen and the amount of blood available in the fetal cardiovascular system. This can affect fetal development of the heart and cause health problems in other areas of the body that are deprived of oxygen.
Poor Lung Development
According to the 2010 U.S. surgeon general's report, fetal exposure to secondhand smoke can cause abnormal lung growth. Weaker lung function before and after birth may result.
Stillbirth
The CDC notes that pregnant women who smoke have more than twice the normal risk for placental abruption, in which the placenta pulls away from the uterus prematurely. This may kill the fetus and result in stillbirth. In a study funded by the National Institutes of Health (NIH), Dr. Stephen Grant found that even women who passively inhale smoke can experience the same effects as active tobacco users.
Premature Birth
According to the CDC, pregnant tobacco users are at a greater risk for early membrane ruptures before labor. In such cases, the fetus will be born prematurely and suffer health problems associated with a shorter developmental term.
Low Birth Weight
CDC data reveal that pregnant women who smoke eat more but may transfer fewer nutrients to their babies. Tobacco users tend to have babies with lower birth weight, and among these, have babies in the lowest fifth to tenth percentile weights. Low birth weight is a major cause of infant death.
Sudden Infant Death
Pregnant smokers carry twice the risk for losing a child to sudden infant death syndrome (SIDS) after she is born. According to the 2006 U.S. surgeon general's report, the tobacco toxins nicotine and cotinine are found in greater concentrations in babies who die from SIDS than from other causes. As the NIH study suggests, even pregnant women who contact these toxins through secondhand smoke or particulate residue may be able to transmit this deadly health problem to their fetuses.
References
- U.S. Department of Health and Human Services (HHS): Secondhand Smoke and Children
- Centers for Disease Control and Prevention: Smoking and Reproductive Health
- U.S. Surgeon General: 2010 Report, How Tobacco Smoke Causes Disease
- HHS: Secondhand Smoke, Firsthand Danger
- CDC: Health Effects of Secondhand Smoke
