Congenital Diaphragmatic Hernia (CDH)

The diaphragm is a thin layer of muscle and tissue that separates the chest and abdominal cavity. It is the major muscle that the body uses to breathe. When your child has a congenital diaphragmatic hernia (CDH), it means that there’s a hole in that layer — or, rarely, that the diaphragm is missing altogether. CDH affects about one in every 2,500 babies.

In CDH, the contents of your child's abdomen, which may include the stomach, intestines, liver, and/or spleen, may go through the hole and into the chest. This prevents the normal development of the lung on that side, and also affects the growth of the other lung. When your child’s lungs don’t fully develop, they will have trouble breathing after birth.

When the organs from the abdomen prevent the lungs from growing, the poor lung growth is called pulmonary hypoplasia. Healthy lungs have millions of small air sacs (alveoli), each of which resembles a balloon filled with air. With pulmonary hypoplasia:

• There are fewer air sacs than normal.
• The air sacs that are present are only able to partially fill with air.
• The air sacs deflate easily because of problems with a lubricating fluid called surfactant.

When this happens, your baby is unable to take in enough oxygen to stay healthy.

There are two kinds of CDH:

• A Bochdalek hernia is a hole in the back of the diaphragm. Ninety percent of children have this type of CDH.
• A Morgagni hernia involves a hole in the front of the diaphragm, which has very little effect on the lung development.

CDH is a serious, life-threatening condition. However, the outlook for babies born with a CDH has greatly improved with advances in treatment.

Every child may experience symptoms differently, but possible symptoms of a Bochdalek diaphragmatic hernia may include:

• Difficulty breathing
• Fast breathing
• 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

A baby born with a Morgagni hernia may or may not show any symptoms. Babies with a Bochdalek type of CDH are more likely to have another birth defect. Complications of a CDH may include:

• Chronic lung disease: This serious condition can require your child to have oxygen or medications after being discharged from the hospital.
• Pulmonary hypertension: This is a condition in which the blood vessels in the lung itself are poorly developed and do not pick up the oxygen as well from the air delivered to the lungs. This may be temporary or can be so severe that it is life threatening.
• Gastroesophageal reflux: This is a condition in which acids and fluids from the stomach move up to the esophagus and can cause heartburn, vomiting, feeding, or lung problems.
• Failure to thrive: Children with the most serious lung problems are most likely to have growth problems. Some require special feeding tubes to give enough calories to grow adequately.
• Developmental delays: These include delays in the ability to roll over, sit, crawl, stand, or walk. Your baby will almost always reach these milestones, just usually at an older age than most children.
• Hearing loss: A hearing test will be performed prior to your baby leaving the hospital.

While we don’t know exactly what causes CDH, scientists believe that multiple genes from both parents — as well as a number of environmental factors that we do not yet fully understand — may contribute.

During routine prenatal care, an ultrasound may reveal the existence or suspicion of a diaphragmatic hernia. If a CDH is diagnosed or suspected during pregnancy, our clinicians will coordinate care through the Fetal Care and Surgery Center. The following tests are performed as part of the evaluation to confirm the presence of a CDH and to find out how severe it is:

• Ultrasound to evaluate for the presence of a CDH and any other abnormalities
• Fetal MRI to evaluate the chest and abdomen in more detail and evaluate lung growth, which can help predict the severity of CDH and identify any other associated abnormalities
• Fetal echocardiogram: An ultrasound of the heart to determine if there are any heart defects, which can be common with CDH.

After all the necessary tests are completed, our experts meet to review and discuss what they have learned. Then they will meet with you and your family to discuss the results and outline the best treatment options.

If a CDH hasn’t been diagnosed before birth, it is usually diagnosed in the newborn period when the baby has trouble breathing. Rarely, with small hernias, and often with Morgagni-type CDH, it is diagnosed later in infancy or in childhood.

The following tests are often done after birth:

• A chest X-ray is done to look at the abnormalities of the lungs, diaphragm, and intestine.
• An ultrasound of the heart (echocardiogram) provides further details about your child's condition.
• A blood test — known as an arterial blood gas — is often performed to evaluate your baby's breathing ability.
• Other blood tests determine if there is a genetic problem.

Every child with a CDH is unique, so treatment can vary based on the level of severity of the CDH, related anomalies, and other factors.

During pregnancy

At Boston Children's, our team in the Fetal Care and Surgery Center assists in the careful management of the mother’s pregnancy and delivery, as well as the stabilization of the baby at birth and postnatal treatment. This comprehensive, multidisciplinary care has resulted in high success rates.

At delivery

Our surgical team is present at the delivery to assist the obstetrician and immediately begin care of your child. Your baby will require a breathing tube and be placed on a breathing machine called a mechanical ventilator before transport to Boston Children’s.

Extracorporeal membrane oxygenation (ECMO) is a heart and lung bypass system that does the job that the heart and lungs would be doing if they developed fully. ECMO may be needed to support your baby’s heart and lungs if they are unable to do so until your baby's condition stabilizes and improves. Having your baby at a hospital like Boston Children's that is equipped with ECMO is vitally important to aid in the management of CDH.

After birth

After your baby is born, they will be taken to and cared for in our Medical-Surgical Intensive Care Unit (MSICU) at Boston Children’s.

• Your baby will remain on the mechanical ventilator.
• A head ultrasound will be performed to evaluate for any abnormality.
• An echocardiogram will be performed to evaluate the heart function and assess for any heart defects. Your baby may be placed on ECMO if needed.
• When your baby's condition has improved, our surgeons will repair the diaphragmatic hernia with an operation.
• During the operation, the abdominal organs will be moved from the chest cavity back to the abdominal cavity and the hole in the diaphragm is closed with stitches if the opening is small, or with a patch if the opening is large or if the diaphragm is absent.

After surgery

Babies will need to remain in the MSICU for a while after surgery.

• Although the abdominal organs are now in the right place, your baby’s lungs and the blood vessels in the lungs are still underdeveloped.
• Your baby will usually need to have breathing support for a period of time after the operation.
• Even after your baby no longer needs help from a breathing machine, they may still need oxygen and medications to help with breathing for weeks, months, or years.
• Pulmonary hypertension (poorly developed blood vessels in the lungs) may persist requiring ongoing treatment.
• Nutrition is important for your baby’s lung and overall growth. Your baby will initially receive nutrition from a special IV, and when your baby has recovered from surgery feeds will be given through a feeding tube placed in the nose that goes into the stomach or intestine.
• Some babies have difficulties with feeding by mouth and require long term feeding tube for feeding.

Before leaving the hospital

Before your baby is discharged, we conduct many tests to make sure that all of their systems are working well.

These tests can include the following:

• EKG
• Chest X-ray
• Echocardiogram
• Hearing test

A diaphragmatic hernia is a complex health concern that requires long-term follow-up. Our outpatient multidisciplinary CDH clinic monitors and treats children born with CDH.

Boston Children’s treats more than 20 newborns with CDH each year with a success rate among the best in the world. Our survival rate for the highest risk groups of babies with CDH is consistently 10 percent higher than that of other centers dedicated to treating this condition.

When a CDH is diagnosed or suspected during pregnancy, our clinicians will coordinate treatment through the Fetal Care and Surgery Center. Children also come into the care of the program when a CDH is diagnosed after birth, and on an outpatient basis for long-term treatment. The Congenital Diaphragmatic Hernia Clinic was established in 1991 and is the first of its type in the world. We follow more than 400 children with CDH with a team of surgeons, pulmonologists, developmental specialists, nutritionists, and cardiologists to assure the best long-term outcome possible.