Birth Defects: Causes, Prevention, and Testing

Jan 18 • 2016

Birth defects are more common than many people realize – in fact, 1 in every 33 babies born in the United States each year suffers from one. A birth defect is classified as a structural change that is present at birth. It can affect almost any part of the body and can have an impact on how the body looks and functions. In honor of National Birth Defects Awareness Month, we’ve outline the causes of birth defects, steps you can take for prevention, and what kind of testing is available.

Causes of Birth Defects
There are a wide variety of birth defects that can occur at any time during pregnancy. There are some specific defects where the cause has been identified, but for others the cause is unknown. Research has shown that a combination of factors like genes, behaviors, and environmental factors are likely the foundation for birth defects.

Some risk factors have been identified, including:

  • Tobacco use, drinking alcohol, or using certain drugs while pregnant
  • Taking particular medications
  • A family history of birth defects
  • Medical conditions like obesity or diabetes while pregnant
  • Being pregnant over the age of 34

It is important to remember that avoiding these situations does not completely prevent the occurrence of birth defects.

Preventing Birth Defects
Because the specific cause of all birth defects is not known, it is impossible to prevent them completely. However, there are several things women can do to decrease the chances of experiencing one.

  • Do not drink alcohol or use tobacco or other drugs
  • See your doctor regularly
  • Begin prenatal care immediately after determining you are pregnant
  • Include 400 micrograms of folic acid in your diet each day
  • Take steps to prevent infections during pregnancy
  • Control any medical conditions you may currently have before getting pregnant
  • Talk to your doctor about medications you currently take to identify possible issue

Testing for Birth Defects
There are two main ways to test for birth defects: screening tests and diagnostic tests.

A screening test cannot tell you for sure that your baby has a birth defect, but can show you the chance that your baby will be born with a particular issue. The test comes back positive or negative for a specific defect – if it is positive, it means your baby is more likely to have it, while a negative test means your baby likely does not have it. However, neither result guarantees that you will have a completely healthy baby. Screening tests are done in the form of blood tests and ultrasounds.

A diagnostic test will show if a baby has a specific birth defect and may be done if a screening test comes back with a positive result. This kind of test involves taking some of your baby’s cells and examining the chromosomes and genes to find any abnormalities.

Most parents have a first-trimester or second-trimester test, but there is an option for an integrated test that combines the results from both tests to create an overall picture of your baby’s health. Choosing whether or not to have these tests at all is completely up to the parents.

If you have questions about your specific risk for birth defects or what tests are available, speak with your doctor to get personalized recommendations.