Birth Defects

What Are Birth Defects?

Birth defects are abnormalities that develop before or during birth. Also called congenital anomalies, birth defects affect the structure, position, and/or function of one or more organs or other part(s) of the body. According to the Centers for Disease Control and Prevention (CDC), birth defects affect about 1 in every 33 newborns each year in the United States. Every year, 120,000–150,000 babies are born with some type of congenital abnormality.

Birth defects range in severity from minor to life-threatening conditions, and there are more than 4,000 different types. Although many congenital abnormalities are treatable (in some cases, even before birth), birth defects are the leading cause of death in babies under the age of 1 year and are responsible for 1 in every 5 infant deaths. Children born with major birth defects often face lifelong challenges.

Any factor that affects normal cell development before birth or adversely affects the birthing process can cause birth defects. Causes include genetic defects and chromosomal abnormalities, environmental factors (e.g., exposure to certain chemicals or medications in the womb), and other factors. In most cases, the cause for congenital anomalies is unknown.

Common Types of Birth Defects

Congenital heart defects—problems with the structure of the heart—are the most common type of major birth defect in the United States, occurring in about 1 in every 100 babies born each year.

Other common types include the following:

• Cleft lip/cleft palate or both (congenital abnormality of the lip and/or roof of the mouth)—The CDC reports that each year in the United States, about 2,650 babies are born with a cleft palate and 4,440 babies are born with a cleft lip with or without a cleft palate.
• Down syndrome (Trisomy 21)
• Eye defects (congenital absence of one or both eyes, eyes that are abnormally small)
• Gastrointestinal system defects (congenital closure, absence, abnormality, etc. in the digestive tract)
• Musculoskeletal defects (e.g., limb deformities)
• Nervous system defects (e.g., spina bifida, cephalic disorders)
• Trisomy 18, Trisomy 13 (cause severe congenital deformation)

Not all birth defects can be prevented, and many of them occur very early in pregnancy—before a woman even knows she is expecting. According to the CDC, women can increase their chances for a healthy pregnancy and baby by making healthy lifestyle choices and managing any existing health conditions before conceiving.

_{Source: U.S. Centers for Disease Control and Prevention (CDC)}