Ask A Scientist

What causes birth defects?

Asked by: Danny Prentice
School: Maine-Endwell Middle School
Grade: 6
Teacher: Kevin Wagstaff
Hobbies/Interests: I like playing soccer and playing on my viola.
Career Interest: N/A

Answer from Janet Ambrogne, Ph.D., R.N., C

Assistant professor, Decker School of Nursing, Bin

Ph.D. School: Medical College of Georgia, Augusta, GA

Research area: Women's health, addictions.

Family: Partner, Sean, and daughter, Angela,2.


A birth defect is a problem that occurs while a baby is developing in the mother’s body. A birth defect may effect how the body looks, functions or both. Birth defects vary in severity and require different treatments.  Most birth defects are discovered either prior to birth or within the first year of life. According to the National Center on Birth Defects and Disabilities, an estimated 120,000 U.S. babies are born annually with a birth defect.  Birth defects are the leading cause of infant death in this country and the fifth leading cause for infant sickness and long-term disability. However with proper treatment, many babies born with birth defects can lead full lives. One way of preventing a birth defect is to remove or minimize the cause. However, this is very complex because there are many different types of birth defects that target different areas of the body such as the heart, the spine and the mouth. In order to determine the cause, each birth defect must be studied separately and extensively. While ongoing research has provided a wealth of information, approximately 70% of birth defects occur for unknown reasons. Certain things may increase the risk of a birth defect. For example, poor diet, cigarette smoking, alcohol use, certain medications and vaccinations during pregnancy have been associated with an increased number of birth defects. Pregnant women who are over the age of 35 have a higher chance of having a child with certain birth defects than younger women. Other birth defects are thought to occur genetically due to alterations in chromosomes.  Many birth defects occur for unknown reasons that may have nothing to do with what the parents did or did not do. While there is no method for preventing all birth defects, lifestyle changes that promote a healthy pregnancy can decrease the risk of some birth defects. It is important to educate prospective parents about the things they can do to promote a healthy pregnancy. These include eating a well-balanced diet, taking a vitamin supplement recommended by a health-care professional, getting plenty of rest, avoiding alcohol, tobacco, street drugs and certain over-the –counter and prescription medications, avoiding contact with chemicals and other things in the environment that may be harmful and regular check-ups with a health-care practitioner.

Last Updated: 3/1/17