What Causes Birth Defects?

Birth defects can be a result of genetics, lifestyle choices and behaviors, exposure to certain medicines and chemicals, infections during pregnancy, or a combination of these factors. However, the exact causes of certain birth defects are often unknown.

Genetics

The mother or father may pass on genetic abnormalities to their baby. Genetic abnormalities occur when a gene becomes flawed due to a mutation (change). In some cases, a gene or part of a gene might be missing. These defects happen at conception (fertilization) and often can’t be prevented. A particular defect may be present throughout the family history of one or both parents.

Nongenetic Causes

The causes of some birth defects can often be difficult or impossible to identify. However, certain behaviors greatly increase the risk of birth defects. These include smoking, using illegal drugs, and drinking alcohol while pregnant. Other factors, such as exposure to toxic chemicals or viruses, also increase risk.

 

 

                                                                 Written by The Healthline Editorial Team
Medically Reviewed by Laura E. Marusinec, M.D. on December 15, 2015