A blue baby is an infant born with a type of congenital heart disease that causes the infant’s skin to have a bluish tint (cyanosis). Cyanosis develops when the tissues and organs of the body do not receive enough oxygen. This, in turn, is caused when much of the blood circulating through the body is “blue” (or oxygen–poor) rather than “red” (or oxygen–rich) to nourish the baby’s tissues. Many different heart defects can cause this condition. Although a blue baby once had very little chance of survival, treatments are now available to help blue babies grow up to live normal, healthy lives.

Depending on the specific heart defect that is causing the condition, treatment could involve medications, a minimally invasive procedure called cardiac catheterization or surgery. These treatments may help to correct, but not cure, the condition.

A blue baby is an infant born with a type of congenital heart disease that causes the infant’s skin to have a bluish tint (cyanosis). Central cyanosis is a condition in which there is too much oxygen–poor blood traveling through the arteries, which normally carry only oxygen–rich blood to nourish the body. In technical terms, cyanosis is diagnosed when the level of reduced (desaturated) hemoglobin exceeds 3  grams per deciliter (g/dl) of blood in the arteries.

Not all cyanosis is caused by congenital heart defects. Peripheral cyanosis, or a slight bluish tinge in the extremities, may occur in healthy, fair–skinned babies. This type of cyanosis is normal. 

Cyanosis may also be caused by lung abnormalities and blood conditions that somehow impede the delivery of oxygen to the tissues and organs of the body.

In general, physicians have identified the five cardiac–related “Ts” that may cause cyanosis in newborns:

A sixth “T” is sometimes called “tons of other diseases,” which might include double outlet right ventricle, pulmonary atresia, hypoplastic left heart syndrome and many others.

In general, the defining feature that unites these various conditions and the underlying cause of blue baby is a cardiac defect known as right–to–left shunt. This describes a condition in which oxygen–poor blood from the body may be “shunted” across an opening in the heart. This allows it to pass from the right side of the heart, where there is normally only oxygen–poor blood, to the left side, where there is oxygen–rich blood. Other conditions may deliver the oxygen-poor blood directly out to the body. The common feature is oxygen-poor blood does not have the opportunity to go to the lungs prior to going out to the body. As a result, some oxygen–poor blood is pumped back out to the body, thus depriving the tissues and organs of necessary oxygen.

The right–to–left shunt may be part of the fundamental defect, or it may be an associated defect that is actually keeping the baby alive by allowing some oxygen–rich blood to be pumped from the heart. In some cases, physicians will create a temporary right–to–left shunt in babies with no cross–circulation between the left side of the heart and the right side in an attempt to keep the baby alive until open-heart surgery can be performed.

Physicians do not yet understand what causes the congenital heart defects that are frequently underlying the baby’s bluish tint (cyanosis). Studies have shown that some congenital heart defects tend to run in families. In addition, a problem pregnancy (e.g., diabetes) or use of certain medications during pregnancy may alert the physician to a possible congenital defect. Some risk factors may prompt the obstetrician to suggest a fetal echocardiogram during the pregnancy to examine the infant's heart in-utero.

In terms of blue baby, there are five cardiac-related congenital diseases, known as the five Ts,that cause most cases of blue baby. They are:

• Tetralogy of Fallot. A condition that involves the “tetralogy” of the following four elements:
  
  
• Ventricular septal defect (VSD). A hole in the wall (septum) between the heart’s two lower chambers (ventricles). The VSD creates a pathway between the right and left ventricle. This results in blood flow between the two chambers mixing together prior to going out to the lungs and body. 
  
  
  
• Pulmonary stenosis. A narrowing stenosis (narrowing) of the pulmonic valve and the muscular region below the valve exists. This decreases the amount of oxygen–poor blood from the right ventricle that can squeeze through the narrowed opening and travel through the pulmonary artery to the lungs. Thus, there is a decreased blood flow to the lungs and a corresponding increase in the amount of blood shunted to the left side of the heart.
  
  
• Hypertrophy (thickening) of the right ventricle. A thickening of the muscle tissue of the right ventricle below the pulmonary valve due to pulmonary obstruction (as described above).
  
  
• Displaced or deviated aorta. Much of the oxygen–poor blood in the right ventricle cannot squeeze through the pulmonary valve and travel to the lungs as it should. This forces the blood to travel up through the displaced aorta, which opens directly into both the right and left ventricles. Therefore, the aorta is receiving both oxygen–poor blood from the right ventricle and oxygen–rich blood from the left ventricle, and carries this mixture to the rest of the body. Because the body is receiving so much oxygen–poor blood, the skin of the child often has a bluish tint (cyanosis).
  
  
• Transposition of the great arteries (TGA). A congenital heart defect (present from birth) in which the “great arteries,” the aorta and the pulmonary artery, are switched, or transposed. In this defect, the aorta leaves from the right ventricle (carrying oxygen–poor blood to the body) and the pulmonary artery leaves from the left ventricle (carrying oxygen–rich blood right back to the lungs). The baby may develop cyanosis because oxygen–poor blood, full of waste products from the cells and organs, is pumped directly back into the body before oxygenation in the lungs can take place.

• Total anomalous pulmonary venous return (TAPVR). A condition in which the pulmonary veins that bring oxygen-rich blood back from the lungs to the heart are not connected to the left atrium. Instead, these veins drain oxygenated blood into the right atrium where it mixes with oxygen-poor blood coming back from the body. This mixture of blood must pass through a hole in the septum between the right and left atria to reach the left ventricle (which can then pump the blood to the rest of the body).
  
  
  
  
• Truncus arteriosus. A condition in which a single great vessel arises from the heart. The aorta, pulmonary arteries and coronary arteries are all part of this common vessel, which allows the complete mixture of oxygen-rich and oxygen-poor blood. This defect is always accompanied by a ventricular septal defect, another heart defect.
  
  
• Tricuspid atresia. A condition in which the tricuspid valve never developed. This condition impedes or totally obstructs blood flow between the right atrium and the right ventricle. As a result, all the oxygen-poor blood mixes with oxygen-rich blood through an atrial septal defect. This mixture then circulates to the body.

The last category is sometimes referred to as the sixth “T”, which stands for “tons of other diseases” that might be the underlying cause of blue baby. These might include:

• Hypoplastic left heart syndrome (HLHS). A condition in which the left side of the heart (including the aorta, aortic valve, left ventricle and mitral valve) is not totally developed. As a result, blood flow, pumping and most other cardiac functions are severely compromised. This can lead to cyanosis because the left ventricle is not adequately pumping enough oxygen–rich blood to the body, and all of the blood is a mixture of oxygen-rich and oxygen-poor blood. 
  
  
• Critical pulmonary stenosis (severe narrowing of the pulmonary valve) or pulmonary atresia (complete closure). Normally, this valve allows blood to flow from the right ventricle to the lungs. When severely narrowed or closed, less blood flow reaches the lungs, leaving less oxygen–rich blood available to circulate through the body.
  
  
• Coarctation of the aorta. A condition in which the aorta is narrowed, usually in a specific place shortly after it emerges from the heart. If the narrowed portion is able to restrict blood flow to the baby, then cyanosis may result.

Aside from the bluish tint (cyanosis) of the skin, nails, lips, tongue or other parts of the body, signs and symptoms of a blue baby include the following:

If an infant exhibits cyanosis, physicians may order any number of tests to help determine the cause of the condition. The diagnostic tests will vary depending on the type, nature and severity of symptoms. Such tests include:

• Chest x-ray to get an image of the heart's chambers, vessels and muscles.  This will also allow the physician to evaluate the lungs and any possibility that there is an associated with them.
  
  
• Electrocardiogram (EKG) to gauge the electrical activity of the heart.
  
  
• Echocardiogram to define the relationships, flows, function, dimensions, and dynamics of all valves, vessels, chambers, and septa.  This is considered the definitive test to evaluate a patient for possible heart disease. There is no recognized risk, radiation, or side-effect to an echocardiogram.. There are both fetal (performed in-utero) and infant echocardiograms available.
  
  
• Cardiac catheterization to determine if valve damage or abnormalities are present. During the cardiac catheterization, an angiogram may be done, in which a special dye (contrast medium) is injected into the blood vessels and chambers to view the activity, relationships, and size of vessel walls, valves and the heart muscle.
  
  
• Blood tests to assess for oxygen levels and other indicators of illness or medical conditions.

In many cases, blue baby syndrome may be apparent shortly after birth but the condition may not become apparent until later. Because blue baby is often the result of an underlying and serious heart defect, newborns who exhibit the cyanosis must be taken to an appropriate pediatric cardiac facility as quickly as possible. There, physicians will attempt to diagnose the defect and develop a plan of action. This may include medications to manage the symptoms, interventional cardiac catheterization procedures or temporary surgeries (palliative) to give the child time to grow until the defect can be fixed or corrective surgeries to fix the underlying defect.

Medications may be used to ease the symptoms of some congenital heart diseases by reducing the workload of the muscles, vessels or chambers of the heart.  A fetus is “protected” from many of the heart problems causing cyanosis because of two temporary communications that permit adequate mixing of blood as the blood is detoured away from the lungs.  This is because the lungs are collapsed and get virtually no blood supply as a fetus and all of the oxygen passes through the placenta from the mother. Some medications, like prostoglandins, may permit continued blood flow to the lungs as was the case during pregnancy by keeping one of these channels, the patent ductus arteriosus, open until more lasting intervention is accomplished.

If medications  are not helpful, then a more invasive treatment option may be advised, such as interventional cardiac catheterization. During this procedure, the physician can employ various strategies to improve valve, vessel and chamber problems. Working through a thin tube, a catheter, that has been inserted through a large blood vessel (e.g., in the upper thigh) and guided to the heart, physicians can open vessels and valves that have narrowed stenosis, close defects in the wall septum between the heart’s chambers and repair malformed vessels. Catheters are also used during palliative operations to create a right-to-left shunt that allows some oxygen-rich blood to be pumped out to the body. Catheter-based techniques are taking the place of open-heart surgery for repair of many heart defects and offer a less invasive treatment option for many children.

Although an approved in-utero surgery is not yet available, there are surgeries that can treat many heart defects soon after birth. These surgeries include the following:

• Shunting procedure. This is usually a temporary way to relieve the symptoms of a defect (palliative surgery), and the defect may be fully repaired after the patient has had some time to grow. In one such procedure, a Blalock-Taussig shunt is used to form a new passageway between the aorta and the pulmonary artery. Thus, additional blood can travel from the aorta to the lungs through the pulmonary artery, increasing the flow and quality of blood flow to the lungs and restoring the patient’s natural pinkish color.
  
  
• Damus-Kaye-Stansel procedure. A surgery performed to repair transposition of the great arteries with subaortic obstruction, in which the pulmonary artery is cut into two segments. The first segment is already connected to the lungs at one end, and the surgeon connects the other end to the right ventricle. Thus, oxygen–poor blood can travel from the right ventricle through the first segment of the pulmonary artery and to the lungs. The second segment is already connected to the left ventricle at one end, and the surgeon connects the other end to the aorta. Thus, oxygen–rich blood can travel from the left ventricle through the second segment of the pulmonary artery and out the aorta, to the rest of the body.
  
  
• Fontan procedure. This is a multiple-staged procedure that corrects such cyanotic conditions as pulmonary atresia, tricuspid atresia, and hypoplastic left heart syndrome (HLHS). It is performed by connecting  the veins returning from the body to the pulmonary artery, thus allowing blood to travel directly from the  body to the lungs, via the pulmonary artery, bypassing the right ventricle.

Many of these patients, both before and after surgery, are at risk of developing endocarditis, an inflammation or infection of the lining of the heart. To prevent this, they will need to take antibioticsbefore any minimally invasive or invasive procedures (e.g., dental cleaning) for life.

While the long–term prognosis depends on the nature and severity of the specific condition(s) and on the appropriate treatment options, chances are better than ever before that properly treated blue babies will grow up to live happy, healthy lives.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients or parents of children with congenital heart defects may wish to ask their doctor the following questions about blue baby syndrome:

1. How soon after birth can blue baby syndrome appear?
   
   
2. What is the first step if my newborn exhibits blue baby syndrome?
   
   
3. What diagnostic tests will my baby given?
   
   
4. What is causing this condition in my baby?
   
   
5. Does my baby have more than one heart defect?
   
   
6. What are the treatment options for the heart defect(s)?
   
   
7. If surgery is necessary, what type will be performed?
   
   
8. Will the surgery need to be done immediately?
   
   
9. How soon will we see an improvement in my baby’s condition?
   
   
10. What will happen if the defect is not corrected?
    
    
11. What is my baby’s prognosis?
    
    
12. How will the defect and surgery affect my baby throughout life?
    
    
13. What symptoms indicate a medical emergency with this condition?
    
    
14. Am I at risk of having another baby with blue baby syndrome?
    
    
15. If this is a staged procedure, how and when will the later procedures be undertaken?
    
    
16. Are there family help groups in the area so that the parents may speak to other families with children with similar conditions?