What is a diaphragmatic hernia?
A diaphragmatic hernia is a birth defect, which is an abnormality that occurs before birth as a fetus is forming in the mother's uterus. An opening is present in the diaphragm (the muscle that separates the chest cavity from the abdominal cavity). With this type of birth defect, some of the organs that are normally found in the abdomen move up into the chest cavity through this abnormal opening.
There are two types of diaphragmatic hernia:
Bochdalek hernia. A Bochdalek hernia usually involves an opening on the left side (85%) of the diaphragm. The stomach, liver, spleen and/or intestines usually move up into the chest cavity.
Morgagni hernia. A Morgagni hernia involves an opening on the right side of the diaphragm. The liver and/or intestines usually move up into the chest cavity.
What causes a diaphragmatic hernia?
As a fetus is growing in its mother's uterus before birth, different organ systems are developing and maturing. The diaphragm develops between the 7th and 12th week of pregnancy. The esophagus (the tube that leads from the throat to the stomach), the stomach, and the intestines are also developing at this time.
In a Bochdalek hernia, the diaphragm may not develop properly, or the intestine may become trapped in the chest cavity as the diaphragm is forming.
In a Morgagni hernia, the tendon that should develop in the middle of the diaphragm does not develop properly.
In both cases, normal development of the diaphragm and the digestive tract does not occur.
Diaphragmatic hernia is a multifactorial condition, which means that "many factors," both genetic and environmental, are involved. It is thought that multiple genes from both parents, as well as a number of environmental factors that scientists do not yet fully understand, contribute to diaphragmatic hernia.
Bochdalek hernia makes up about 80 to 90 percent of all cases.
Morgagni hernia makes up two percent of all cases.
Why is a diaphragmatic hernia of concern?
The lungs are developing at the same time as the diaphragm and the digestive system. A diaphragmatic hernia allows abdominal organs to move into the chest cavity, instead of remaining in the abdomen as they are developing. With the heart, lungs, and abdominal organs all taking up space in the chest cavity, the lungs do not have space to develop properly. This underdevelopment of the lungs is called pulmonary hypoplasia.
A diaphragmatic hernia is a life-threatening illness. When the lungs do not develop properly during pregnancy, it can be difficult for the baby to breathe after birth. Healthy lungs have millions of small air sacs (alveoli), which resemble a balloon filled with air. With pulmonary hypoplasia:
There are fewer air sacs than normal.
The air sacs that are present are able to only partially fill with air.
The air sacs deflate easily due to a lack of a lubricating fluid called surfactant.
When these conditions are present, the baby is unable to take in enough oxygen to stay healthy.
The intestines also may not develop properly, especially if they are not receiving enough blood supply while they are developing. A good blood supply is necessary for the intestines to develop correctly, and to be healthy and function properly.
What are the symptoms of a diaphragmatic hernia?
The symptoms of a Bochdalek diaphragmatic hernia are often observable soon after the baby is born. The following are the most common symptoms of a Bochdalek diaphragmatic hernia. However, each child may experience symptoms differently. Symptoms may include:
Fast heart rate
Cyanosis (blue color of the skin)
Abnormal chest development, with one side being larger than the other
Abdomen that appears caved in (concave)
A baby born with a Morgagni hernia may or may not show any symptoms.
The symptoms of diaphragmatic hernia may resemble other conditions or medical problems. Always consult your baby's physician for a diagnosis.
How is a diaphragmatic hernia diagnosed?
After birth, your baby's physician will perform a physical examination. A chest x-ray is done to look at the abnormalities of the lungs, diaphragm, and intestine. A blood test known as an arterial blood gas is often performed to evaluate the baby's breathing ability.