What is Congenital Diaphragmatic Hernia?
Congenital Diaphragmatic Hernia (CDH) is a condition where a hernia (hole) in the diaphragm (the layer of muscle that separates the chest from the abdominal cavity and is used for breathing) develops during 8th week of gestation. More rarely, the diaphragm is missing. The hernia allows the stomach, intestines, liver and spleen to move up into the chest, preventing the fetus's lungs from developing properly. Fetuses do not need to use their lungs while in the uterus, but after birth have trouble breathing. Congenital Diaphragmatic Hernia is a life-threatening condition once the baby is born that requires skilled intensive care and surgery. Many babies with CDH will have additional birth defects and require long-term follow-up care. Sanford Health's Fetal Care Center manages and coordinates care with our Neonatal Intensive Care Units and neonatal gastroenterologists to deliver optimal care for babies diagnosed with CDH.
How is Congenital Diaphragmatic Hernia Caused?
Congenital diaphragmatic hernia is thought to be caused by multiple genes from both parents as well as potential environmental factors. The exact cause remains unknown. Having a parent or sibling with CDH increases your risk. There is a higher occurrence in the left lung. The condition is seen in 1 out of every 2,500 to 5,000 live births.
How is Congenital Diaphragmatic Hernia Diagnosed?
A congenital diaphragmatic hernia diagnosis is usually made during a routine prenatal ultrasound at 18 to 21 weeks. Fetal MRI confirms the diagnosis. Additional genetic testing may be done to rule out genetic conditions. An ultrasound of the fetus's heart (echocardiogram) is done to determine potential heart involvement. It is important to note that there are varying degrees of CDH, and that the fetus's outcome depends highly on how developed the lungs are at birth. In the most severe cases, the lungs are too small to sustain life, despite intervention. While there are treatment options to promote lung growth in the fetus, there is no test during pregnancy that measures a fetal lung function. The true severity of the condition cannot be known until after birth.
If CDH is not diagnosed until after birth, the baby will undergo a chest x-ray, arterial blood gas testing (measures the oxygen in the blood), and an ultrasound of the heart (echocardiogram) to confirm the diagnosis and determine severity.
There are two primary types of CDH:
- Bochdalek Hernia comprises 90% of cases. It is distinguished by a hole in the back of the diaphragm. Signs and symptoms after birth include difficulty breathing, fast breathing, fast heart rate, blue color to skin, abnormal chest development (one side of the chest may appear larger) and an abdomen that appears sunken. Nearly 20% of babies with this type will also have a heart defect and 5 – 16% have a chromosomal condition, such as Down Syndrome.
- Morgagni's Hernia accounts for 2% of cases and involves a small hole in the front of the diaphragm. Most babies born with this do not show any signs or symptoms.
What Does it Mean for My Baby?
Congenital diaphragmatic hernia symptoms in a baby include breathing difficulty, fast breathing, fast heart rate, cyanosis (bluish skin from lack of oxygen), chest irregularities (one side larger than the other), and a sunken abdomen. Breathing difficulties appear immediately at birth. Surgery will be required to return the abdominal contents back to the abdomen and repair the hernia, allowing the lungs to continue to develop. Most infants with CDH require long-term follow-up care. Because their lungs are not as developed, they may suffer from pulmonary hypoplasia – a condition characterized by the lungs having fewer air sacs (alveoli) than normal, difficulty fully filling the lungs with air and problems with the lungs deflating easily due to a lack of surfactant (lubricating fluid in the lungs). This condition can lead to long-term breathing difficulties, heart problems and feeding/development challenges. Children with mild CDH may have little to no problems after surgery and continue to develop normal lung capacity.
If I am Diagnosed with Congenital Diaphragmatic Hernia, What Happens Next?
You will be closely monitored throughout your pregnancy. Your Fetal Care team will work to determine if there are other abnormalities and estimate the severity of the CDH. Fetuses who have part or all of their liver within the chest cavity have a more severe form of CDH. Measurements are done to gauge the fetus's lung-to-head ratio (size of the fetal lungs). Smaller lungs indicate a higher severity.
Most CDH babies can be delivered vaginally. However, because they require intensive care, careful planning with your Fetal Care team is necessary to ensure that delivery takes place in a hospital equipped with specialists and an NICU Level III that can provide a full range of support to the baby after birth.
How is Congenital Diaphragmatic Hernia Treated?
Congenital diaphragmatic hernia treatment requires surgery to move the abdominal contents back into the abdomen and close the hernia or, if the diaphragm is missing, placement of an artificial one. In the most severe cases, fetuses may be considered for a FETENDO fetal surgery called "fetoscopic temporary trachea occlusion," that enlarges the lung. The fetal lung continually makes fluid that is expelled through the fetus's mouth and into the amniotic fluid. In this procedure, surgeons block the trachea (windpipe), forcing the fluid to build up and expand in the lung which pushes the abdominal contents back down. The goal is have the baby born with lungs large enough to breathe on his or her own. This intervention is performed between 26 and 28 weeks gestation.
Most cases of CDH are repaired following birth. Once the baby is stabilized with breathing support and sometimes the assistance of a temporary heart-lung machine (ECMO), surgery takes place within three days. Babies will be required to stay in the NICU. The length of their stay will vary depending on their condition and response to surgery.
What is the Long-term Prognosis for CDH?
The survival rate in severe CDH cases with full medical support is 50 - 70%. Children's lungs continue to develop for the first nine years of life. Most children with CDH will experience some long-term developmental delays.
Where Can I Find More Information and Support?
Talk to your Sanford physician for more information on congenital diaphragmatic hernia. Our genetic counselors are also available, as well as spiritual counsel.