What are congenital heart defects?

Congenital (kon-JEN-i-tal) heart defects are problems with the heart's structure that are present at birth. These defects can involve the interior walls of the heart, valves inside the heart, or the arteries and veins that carry blood to the heart or out to the body. Congenital heart defects change the normal flow of blood through the heart.

There are many different types of congenital heart defects. They range from simple defects with no symptoms to complex defects with severe, life-threatening symptoms.

Congenital heart defects are the most common type of birth defect, affecting 8 of every 1,000 newborns. Each year, more than 35,000 babies in the United States are born with congenital heart defects. Most of these defects are simple conditions that are easily fixed or need no treatment.

A small number of babies are born with complex congenital heart defects that need special medical attention soon after birth. Over the past few decades, the diagnosis and treatment of these complex defects has greatly improved.

As a result, almost all children with complex heart defects grow to adulthood and can live active, productive lives because their heart defects have been effectively treated.

What are birth defects?

Birth defects are structural or functional abnormalities present at birth that cause physical or mental disability. Some may be fatal.

Researchers have identified thousands of different birth defects. Currently, birth defects are the leading cause of death for infants during the first year of life.

What causes birth defects?

Birth defects have a variety of causes, such as:

• Genetic problems caused when one or more genes doesn't work properly or part of a gene is missing
• Problems with chromosomes, such as having an extra chromosome or missing part of a chromosome
• Environmental factors that a woman is exposed to during pregnancy, such as rubella or German measles while pregnant, or using drug or alcohol during pregnancy.

What are the different types of birth defects?

There are two main types of birth defects: structural and functional/developmental.

Structural birth defects are related to a problem with body parts. Some physical problems include cleft lip or cleft palate, heart defects, such as missing or misshaped valves, and abnormal limbs, such as a club foot. They also include neural tube defects, such as spina bifida, problems that are related to the growth and development of the brain and spinal cord.

Functional birth defects are related to a problem with how a body part or body system works. These problems often lead to developmental disabilities and can include things such as:

• Nervous system or brain problems - such as learning disabilities, mental retardation, behavioral disorders, speech or language difficulties, convulsions, and movement trouble. Some examples of birth defects that affect the nervous system include Autism, Down sysdrome, Prader – Willi syndrome, and Fragile X syndrome.
• Sensory problems - such as blindness, cataracts and other visual problems, and varying degrees of hearing loss including deafness
  
  Metabolic disorders - involve a body process or chemical pathway or reaction, such as conditions that limit the body's ability to get rid of waste materials or harmful chemicals. Two common metabolic disorders are phenylketonuria (PKU) and hypothyroidism.

• Degenerative disorders--are conditions that might not be obvious at birth, but cause one or more aspects of health to steadily get worse. For example, X-linked adrenoleukodystrophy (X-ALD), which was the focus of the movie Lorenzo's Oil, Rett syndrome, muscular dystrophy, and lysosomal disorders are examples of degenerative disorders. In some cases, birth defects are caused by a combination of factors. Some recognized patterns of birth defects affect many parts or processes in the body, leading to both structural and functional problems.

In some cases, birth defects are caused by a combination of factors. Some recognized patterns of birth defects affect many parts or processes in the body, leading to both structural and functional problems.

Congenital heart defects can be classified into several categories according to the problems your child may experience. They include the following:

• Problems that cause too much blood to pass through the lungs -- These defects allow oxygen-rich (red) blood that should be traveling to the body to re-circulate through the lungs, causing increased pressure and stress in the lungs. Examples include the following:
• patent ductus arteriosus (PDA)
• atrial septal defect (ASD)
• ventricular septal defect (VSD)
• atrioventricular canal (AV canal or AVC)

• Problems that cause too little blood to pass through the lungs — These defects allow blood that has not been to the lungs to pick up oxygen (and, therefore, is oxygen-poor) to travel to the body. The body does not receive enough oxygen with these heart problems, and the baby will be cyanotic, or "blue." Examples include the following:
• tricuspid atresia (TA)
• pulmonary atresia (PA)
• transposition of the great arteries (TGA)
• Tetralogy of Fallot (TOF)

• Problems that cause too little blood to travel to the body -- These defects are a result of underdeveloped chambers of the heart or blockages in blood vessels that prevent the proper amount of blood from traveling to the body to meet its needs. Examples include:
• coarctation of the aorta
• aortic stenosis
• pulmonary stenosis

• A combination of several heart defects -- These combinations create a more complex problem that can fall into several of these categories. Complex combination of heart defects include:
• hypoplastic left heart syndrome (HLHS)
• truncus arteriosis
• total anomalous pulmonary venous return (TAPVR)

congenital heart defects