Everyone knows there are some very serious risks associated with smoking cigarettes and the risks affect the baby a woman carries when she chooses to smoke during pregnancy. A recent study, funded by the Centers for Disease Control and Prevention (CDC), has identified the four most crucial months when smoking is most likely to cause heart defects in a fetus.

Congenital heart defects (CHDs) are more likely to occur in the babies of mothers who smoked cigarettes one month before pregnancy and the first three months of the pregnancy. The most common birth defect associated with maternal smoking is a septal heart defect, or a hole between the left and right chambers of the heart, which interrupts the steady flow of oxygen and blood to the rest of the body.

In addition to the septal heart defects, babies also face the risk of developing conotruncal defects, which cause poor blood flow from the lower chamber of the heart, and right- and left-side obstructive defects. Obstructive defects limit the free flow of blood from the right or left side of the heart, depending upon which side of the heart the defect is located.

In the United States, eight to 10 live births out of every 1,000 are associated with CHDs, which often lead to death of the infant during his or her first year of life. Those who survive face a lifetime of disabilities that usually require frequent surgeries and extended hospital stays.

Data for the CDC study was gleaned from the National Birth Defects Prevention study, the largest ever conducted to identify causes of birth defects in US babies. Nine states – California, Utah, Texas, Arkansas, Iowa, Georgia, North Carolina, New York, and Massachusetts – provided the data, which included 3,067 infants born with CHDs and a control group of 3,947 healthy infants.

There are other pregnancy-related risks associated with smoking before and during pregnancy in addition to CHDs:

• Smokers have a harder time getting pregnant in the first place
• Miscarriage is a bigger risk for smokers
• Mother and baby both face health problems during pregnancy when the mother smokes. The placenta, which supplies oxygen and nutrients to the baby during pregnancy, is often adversely affected by maternal smoking
• Premature deliveries and low birth weight, both dangerous to a newborn, occur more often when the mother smokes
• Cleft lip and cleft palate, birth defects on the face and in the mouth, occur more often when mothers smoke
• SIDS (Sudden Infant Death Syndrome) is more likely to occur when mothers smoke during and even after pregnancy

The risk and severity of birth defects is linked directly to the amount of cigarettes a woman smokes before, during, and after pregnancy.

Source: CDC