What Are Birth Defects?
While still in the womb, some babies have problems with how their organs and body parts form, how they work, or how their bodies turn food into energy. These health problems are called birth defects. There are more than 4,000 different kinds of birth defects, ranging from minor ones that need no treatment to serious ones that cause disabilities or require medical or surgical treatment.
What Are the Types of Birth Defects?
If a baby is born with a part of the body that is missing or malformed, it is called a structural birth defect. Heart defects are the most common type of structural defect. Others include spina bifida, cleft palate, clubfoot, and congenital dislocated hip. When there is a problem with a baby’s body chemistry, it is called a metabolic birth defect. Metabolic defects prevent the body from properly breaking down food to create energy. Examples of metabolic defects include Tay-Sachs disease, a fatal disease that affects the central nervous system, and phenylketonuria (PKU), which affects the way the body processes protein.
What Causes Birth Defects?
In most cases, doctors don’t know what caused a baby’s birth defect. When the cause is known, it might be environmental (such as a baby’s exposure to chemicals or viruses while in the womb), a problem with genes, or a combination of these things.
If a mother has certain infections during pregnancy, her baby can have a birth defect. Other conditions that cause defects include rubella and chickenpox (varicella). Fortunately, many people get vaccinated against these diseases so these infections are rare. Also, alcohol abuse by the mother may cause fetal alcohol syndrome, and certain medicines taken by the mother can cause birth defects.
One well-known birth defect caused by a chromosome problem is Down syndrome. A baby develops Down syndrome after getting one extra chromosome. Other genetic defects happen when both parents pass along a faulty gene for the same disease. A disease or defect also can happen when only one parent passes along the gene for that disease. This includes birth defects such as achondroplasia (a form of dwarfism) and Marfan syndrome. Finally, some boys inherit disorders from genes passed onto them only by their mothers. These defects, which include conditions like hemophilia and color blindness, are called X-linked because the genes are carried on the X chromosome.
How Are Birth Defects Diagnosed?
Many birth defects are diagnosed even before a baby is born through prenatal tests. Prenatal tests also can help determine if a mother has an infection or other condition that is dangerous for the fetus. Knowing about a baby’s health problems ahead of time can help parents and doctors plan for the future. Other birth defects are found during routine newborn screenings. With parents’ permission, babies are tested after birth to screen for certain birth defects that need to be treated. In the U.S., exactly what a baby is tested for varies from state to state, although all states screen for phenylketonuria (PKU), congenital hypothyroidism, sickle cell disease, and about 30 other conditions. Parents should ask health care providers or the hospital nursery which tests their state does.
Can Birth Defects Be Prevented?
Many birth defects can’t be prevented, but a woman can do some things before and during pregnancy to help lower the chances of having a baby with a birth defect. Before pregnancy, women should:
• make sure their vaccinations are up to date
• make sure they don’t have any sexually transmitted diseases (STDs)
• get the daily recommended dose of folic acid before trying to conceive
• avoid unnecessary medicines and talk to their doctor about medicines they are taking If there’s a family history of birth defects or a woman is part of a high-risk group, she should consider meeting with a genetic counselor to determine her baby’s risk.
During pregnancy, it’s important to take prenatal vitamins and eat a healthy diet in addition to taking the following precautions:
• don’t smoke and avoid secondhand smoke
• don’t drink alcohol
• avoid all illicit drugs
• get exercise and plenty of rest
• get early and regular prenatal care By following these pregnancy precautions, women can help reduce their babies’ risk of birth defects.