January is National Birth Defect Prevention Month. Birth defects include abnormalities of body structures, metabolism or function. Most birth defects are the result of both genetic and environmental factors. Genetic causes can include gene defects or chromosome abnormalities over which we have little control. In addition, many environmental factors can play a role in the development of birth defects. To some extent environmental factors can be preventable. In some instances, women can make lifestyle changes that can modify environmental factors and minimize the risk posed to a newborn.
Avoidance of certain substances can decrease the risk of birth defects. For example, one of the most common birth defects is fetal alcohol syndrome. Children with this disorder can suffer from defects that affect their ability to learn. Because no one knows exactly what level of alcohol use causes the problems, women should avoid alcohol altogether while pregnant. Much the same can be said about other substances of abuse including tobacco products and illegal drugs. Although marijuana is legal in some states the use of marijuana during pregnancy is not recommended by the American College of Obstetricians and Gynecologists because, while research is limited, there is a possible risk of disruptions of normal brain development, smaller infants, and stillbirths with marijuana use.
Many women of child-bearing age have chronic medical problems that require them to take medications regularly. Women who take medications regularly, particularly acne or seizure medications, should check with their doctors about any potential effects their medications may have on a fetus. On the other hand, some chronic conditions like diabetes or high blood pressure can themselves increase the risk of birth defects. As a result, appropriate management of these chronic conditions can decrease their potential harm to the newborn.
Women can prevent some birth defects by simply taking extra vitamins before becoming pregnant. The best example of this is spina bifida, an abnormality of the development of the spinal cord. Fortunately, women can plan ahead and increase their intake of folic acid (folate) before becoming pregnant to help decrease the risk of spina bifida. Many foods are fortified with folic acid, and it is available as a dietary supplement. The recommended dose of folic acid is 400 µg daily and for women who’ve had an infant with a neural tube defect (such as spina bifida) the dose is 4000 µg daily.
Certain infections can affect a fetus. Some common illnesses like chicken pox, rubella, fifth disease, and various sexually transmitted diseases can have devastating effects on a fetus. Women should make sure they are fully immunized against vaccine-preventable diseases. Their doctors can screen for STDs to help minimize the risk these infections pose with treatment. Also, women should not change kitty litter boxes to avoid exposing the fetus to toxoplasmosis, a type of parasite.
In spite of the fact that we have no control over our genetic make up, families with a known history of genetic defects can seek counseling from specialists (geneticists) about the risks of passing an inheritable trait to their offspring. During pregnancy, ultrasounds, special blood tests, and amniocenteses can help identify defects before the birth of the child. After birth, the state metabolic screen for 31 genetic disorders, the hearing screen, and congenital heart disease screening can help identify defects that may not be recognized right at birth. Future parents who are interested in learning more about the prevention of birth defects can arrange preconception visits with an obstetrician or prenatal visits with a pediatrician. For more information they can also visit the March of Dimes website: www.marchofdimes.com.
Carlos Armengol, MD FAAP