Preventing Birth Defects

About 1 out of every 33 babies born in the US each year is born with a birth defect.  Birth defects range from minor abnormalities to critical, life-threatening conditions.  Let's talk about what they are and what women need to know to decrease their chance of having a baby born with a birth defect.

What are birth defects?

They are structural abnormalities that occur during a baby's development in the womb.  They can affect almost any part of the body and sometimes affect more than one part of the body.  They may be visible on the body, or they may be internal.  They can also affect the function of the body.  Some babies born with birth defects need surgery within the first few days of life in order to survive.  Some birth defects may also affect a person's expected life span.

How are birth defects identified?

Most birth defects are found within the first year of life; some are quite apparent at birth.  Some birth defects are minor or cause no significant functional limitations, and some may not be identified until much later.

Some birth defects are easy to see, such as a cleft lip or an extra finger.  Others require special tests to make the diagnosis, such as heart defects, which require an ultrasound of the heart, or hearing loss, which requires a hearing test to detect the problem.

Intellectual disability can also be a birth defect caused by factors occurring during pregnancy.

What causes birth defects?

While we do know the cause of some birth defects, for most birth defects, we don't know their cause.  We think they are caused by a complex mix of factors, which can include inherited genes, behaviors, and exposure to certain things in the environment.  

Most birth defects begin during the first 3 months of pregnancy, when a baby's internal organs are developing.  The first 3 months is a very important stage of development for the unborn baby.  Because the tissues and organs continue to grow and develop throughout pregnancy, birth defects can occur at any stage of pregnancy.  

Even though we still have a lot to learn, thanks to past research, we know a great deal about birth defects, including some definite causes of birth defects and some things that probably increase the chances of having a baby born with a birth defect.  

Here are some of the things that increase the risk of birth defects:

• Drinking alcohol, or taking certain drugs during pregnancy
• Smoking during pregnancy
• Taking certain medications 
• Family history of birth defects
• Having certain infections during pregnancy
• High body temperature in mother during pregnancy, due to fever or a high heat exposure
• Being an older mother, or sometimes having an older father, as the risk of chromosomal abnormalities increases with age.

These are the primary things that we know about.  Having one or more of these risk factors doesn't mean you will have a baby with a birth defect, but these factors do increase your risk.  Sometimes a baby is born with a birth defect when none of these risk factors are present.  This points to the complex nature of birth defects.  

Next week we will talk more about how you can prevent birth defects.  It is important to know what you can do to lower your risk.

If you have any questions about preventing birth defects, please log into your account and send us your question. We are here to help.

Dr. Anita Bennett MD - Health Tip Content Editor