Birth Defects

What are Birth Defects? Image

Birth defects, also called “congenital abnormalities,” are physical abnormalities present in a newborn at birth. These conditions can affect the structure and/or function of various parts of the body. A variety of conditions can cause a birth defect, including genetic mutations and exposure to toxic substances during fetal development. Other birth defects have causes that are not well understood.

According to the Centers for Disease Control and prevention, birth defects affect approximately one in every 33 babies born in the United States.

In 1998, The Birth Defects Prevention Act was signed into law. It allows the CDC to:

  • Collect and analyze data about birth defects
  • Conduct research about the causes and prevention of these conditions
  • Provide information and education to the public about birth defects.

Educating the general public about birth defects’ causes and prevention may help to reduce the incidence of some birth defects.

Birth Defect Terminology

Specific terms are commonly used to describe the physical malformations associated with different birth defects. Other, general terms are used to describe types of birth defects occurring in different body structures. Important terms to know include:

  • Agenesis: The complete lack of formation or absence of a certain structure
  • Atresia: Abnormal blockage or complete closure of a passage or orifice in the body
  • Congenital: Present from birth
  • Dysgenesis: Incomplete or abnormal formation of a structure
  • Stenosis: Partial blockage of a passage or orifice
  • Hernia: Protrusion of an internal organ through an abnormal space or weakness in the walls of the cavity containing the organ
  • Teratogen: An environmental agent capable of causing birth defects through maternal exposure during pregnancy.

Knowledge of these terms can help you to understand how different birth defects affect the body’s structures.

Types of Birth Defects

Birth defects can occur in any of the body’s structures or systems. These include the:

Birth defects usually involve a malformation or absence of a particular physical structure, which can cause localized or widespread problems with body function.

Diagnosis and Treatment of Birth Defects

Some birth defects can be detected before birth, so doctors can prepare to treat them immediately after a baby is born. Other birth defects may not be detected until after birth. You may have different treatment options if your doctor detects a birth defect in your baby. Birth defects vary widely in terms of how they present themselves, and therefore, in how they are treated. Some birth defects can be debilitating or even fatal, while others can be treated early, resulting in normal (or nearly-normal) functioning.


Centers for Disease Control and Prevention. (n.d.). Birth defects. Retrieved April 3, 2010, from:

Kids Health. (n.d.). Prenatal tests. Retrieved April 3, 2010, from:

Texas Department of State Health Services. (n.d.). Birth defects glossary.Retrieved April 3, 2010, from:

Texas Department of State Health Services. (2005). Birth defects risk factor series: Atresia/stenosis of the small intestine. Retrieved April 3, 2010, from: