Congenital Diaphragmatic Hernia (CDH)

CDH is a rare abnormality defined by a hole in the diaphragm, the muscular layer that separates the abdomen from the chest. It is a result of failed closure of the pleuroperitoneal membrane during development. Normally the diaphragm helps with your breathing, but since there is hole in the diaphragm and no separation between the abdomen and chest, organs from the abdomen such as the stomach, intestines, and liver can move into the chest and cause problems with lung growth, breathing and possibly heart function.

CDH is generally diagnosed on routine anatomy ultrasound around 20 weeks gestation but can sometimes be detected earlier or later in pregnancy. Since the cause is not entirely known, it is hard to predict who will be at risk for CDH.

Yes, the position of the defect can vary. Left-sided hernias are more common than right-sided hernias. Left-sided hernias can cause the stomach and intestines to move into the chest while right-sided hernias can cause the liver to move into the chest. Both can cause significant underdevelopment of the lungs and compression of the heart.

Regular ultrasounds will be performed to assess the type and extent of the defect and to evaluate for any other structural abnormalities. We will also recommend an amniocentesis to test for genetic abnormalities. This is a safe and common procedure in which a needle is inserted into the amniotic fluid and a small amount of fluid is taken out to test the genetics of the baby. Additionally, a fetal echocardiogram will be performed by a trained pediatric cardiologist, and we will also recommend a fetal MRI to assess the volume of the lungs.

CDH occurs in about 1 in every 2500-5000 babies.

About 20% of CDH cases are related to major chromosomal abnormalities such as trisomy 13, trisomy 18, and tetrasomy 12p. Another 10% of cases are related to other genetic conditions such as Fryns syndrome. The remainder of case are considered isolated and have not been linked to any specific risk factors.

The size of the defect, degree of lung hypoplasia (underdevelopment), associated genetic or structural abnormalities particularly of the heart, and birthweight all play a role in the risk of complications. Long-term respiratory complications include chronic lung disease, need for oxygen at home, pneumonias, and pulmonary hypertension. Gastrointestinal complications include feeding problems, reflux, and growth problems. There is also risk of developmental delay, behavioral disorders, and hearing loss. There can be chest wall abnormalities and other orthopedic abnormalities following surgical repair. Nonetheless, recent studies have shown that most affected children with CDH have good overall health and quality of life following successful repair and discharge from the NICU.

A small number of centers offer a fetal surgery known as a fetoscopic temporary balloon tracheal occlusion to enlarge the fetal lung. It is only offered in cases of severe CDH and there are several other criteria that must be met prior to this procedure. An amniocentesis must be done prior to consideration to rule out any genetic problems. For further information, please speak with your care team.

Once a diagnosis of CDH is made, your care team will meet with you to talk about your baby’s condition and the remainder of the pregnancy. You will have more frequent ultrasounds and other tests (echo and MRI) to monitor the health of the baby. Your care will be individualized based on the circumstances and your wishes, and our specialists will guide you during every step of the way. Delivery is generally recommended at term (between 37-39 weeks) to allow for optimal growth of the baby. This may vary based on the presence of other complications. Our team always makes recommendations based on safety for both the mother and baby. A vaginal delivery is possible if there are no other medical reasons that warrant a Cesarean delivery.

After delivery, your baby will transfer to the NICU, where specialized doctors and nurses will provide care for your baby. A nasogastric tube (NG tube) will be placed to decompress the baby’s stomach and intestines. The baby’s respiratory status will be evaluated. Most likely, if the baby is having difficulty breathing, a breathing tube will need to be placed promptly to allow oxygen to reach the baby’s organs. Surgical repair is generally delayed at least 48 to 72 hours to allow the baby’s lungs to adapt. This also allows for improvement in pulmonary hypertension (high blood pressure in the arteries of the lungs). In very severe cases, ECMO may be required due to worsening clinical status and oxygenation.

Extracorporeal membrane oxygenation (ECMO) is life-saving medical therapy that provides temporary support to the heart and lungs while they are unable to function. It provides the blood with oxygen and helps to pump the blood to the baby’s organs. The baby must meet certain criteria to be a candidate for ECMO. For families with CDH, it is important to deliver at a specialized center such as UCLA due to the ability to access ECMO quickly.

When the baby is stable for definitive surgical repair, your surgeon will perform a surgery to fix the hole in the baby’s diaphragm. The surgery places the abdominal organs from the chest back into the belly and create space in the chest to allow to lungs to grow. There are various techniques in this repair and the doctors will discuss with you the best approach for your baby. Traditionally, an incision is made. However, the minimally invasive thoracoscopic approach is also possible depending on how your baby is doing after birth. If the defect is large, a patch may have to be placed to cover the defect.

CDH is rare and is not considered an inherited condition. It is unlikely to recur, however our genetic counselors and care team will discuss this in further detail with you.