At least one in 10 women smokes and/or drinks alcohol during pregnancy. While most women are aware that smoking and drinking are not recommended during pregnancy, many women don't realize the specific risks associated with these exposures. From growth restriction to preterm birth to birth defects, smoking and drinking while pregnant can cause a host of medical problems for infants. The more a woman smokes and/or drinks, the greater the risks for the baby.
Growth Restriction and Low Birthweight
Both smoking and drinking can affect the growth of the baby. Cigarette smoke contains carbon monoxide, among other toxins, which reaches the baby through the placenta. Smoking also constricts the blood vessels that lead to the placenta, resulting in decreased blood flow to the fetus. Because the fetus obtains its nutrients and oxygen through the mother's bloodstream, reduced blood flow means growth restriction for the fetus. Alcohol in the bloodstream also restricts the baby's growth. The combined effect of both smoking and drinking during pregnancy is even more detrimental; according to a study published in the journal "Epidemiology" in 1995, 30 percent of babies born to women who both smoke and drink are born underweight. Small, low-birthweight babies face increased chances for respiratory problems and other short-term issues as newborns and may also develop lasting complications such as learning disabilities, cerebral palsy and vision and hearing problems.
Preterm Birth
The majority of low-birthweight babies are born prematurely. Even babies of normal birthweight who were exposed to smoke and/or alcohol during pregnancy can be born prematurely. Preterm babies (born before 37 weeks gestation) can suffer from various health problems, including respiratory distress syndrome, intracranial hemorrhage (bleeding in the brain), anemia and a heart problem called patent ductus arteriosus. Most of these problems can be treated to at least some extent, but the most severe cases they can result in long-term consequences such as cerebral palsy, mental retardation and behavioral problems.
Birth Defects
According to the March of Dimes, alcohol is a known teratogen, meaning that it has been demonstrated to cause birth defects. Many organs and parts of the body can be adversely affected by alcohol, including the heart, brain, spine, and face. Some medical problems, such as heart defects, can be surgically repaired after birth. Others, such as brain damage, are not correctable. A report by the Centers for Disease Control and Prevention from 2004 stated that approximately 1,000 to 6,000 babies per year in the United States are born with fetal alcohol syndrome (FAS). FAS is a constellation of abnormalities consisting of facial anomalies, heart defects and mental deficiency, among other problems.
Studies vary regarding whether smoking during pregnancy can cause birth defects. One large study, published in "Plastic and Reconstructive Surgery" in 2000, found an increased risk for cleft lip with or without cleft palate from smoking. Several other birth defects have also been implicated with smoking, including digestive system abnormalities, heart defects and limb reduction defects. The time of greatest risk for birth defects from alcohol and smoking is during the first trimester of pregnancy, when the baby's organs are forming. Therefore, even when the mother stops drinking and/or smoking once she finds out she is pregnant, damage may have already been done to the baby.
References
- "Epidemiology"; The Association of Moderate Maternal and Paternal Alcohol Consumption with Birthweight; GC Windham; Nov. 1995
- "Plastic and Reconstructive Surgery"; Maternal Cigarette Smoking During Pregnancy and the Risk of Having a Child With Cleft Lip/Palate; KC Chung et al; Feb. 2000
- "Centers for Disease Control and Prevention National Task Force on FAS/FAE"; Fetal Alcohol Syndrome: Guidelines for Referral and Diagnosis; J Bertrand et al; July 2004
