During a routine prenatal ultrasound, expectant parents hope for reassurance and a clear picture of their healthy, developing baby. Receiving the news that there is a serious problem can be a shocking and terrifying experience. One of the most serious birth defects that can be identified before birth is a congenital diaphragmatic hernia (CDH). This is a life-threatening condition where a hole in the baby’s diaphragm allows abdominal organs to move into the chest cavity, severely impairing lung development. While a diagnosis of CDH is one of the most challenging a family can face, it is crucial to understand that remarkable advances in neonatal intensive care and pediatric surgery have dramatically improved the chances of survival for many babies born with this complex condition.

A diaphragmatic hernia is a condition where there is an abnormal opening or hole in the diaphragm. The diaphragm is the large, dome-shaped sheet of muscle that separates the chest cavity (containing the heart and lungs) from the abdominal cavity (containing the stomach, intestines, and liver). It is the most important muscle used for breathing.

There are two main types of diaphragmatic hernias:

1. Congenital Diaphragmatic Hernia (CDH): This is a birth defect. The hole exists because the diaphragm failed to form completely during fetal development. This is the most common and most serious type, and it will be the primary focus of this article.
2. Acquired Diaphragmatic Hernia: This type occurs later in life, usually as the result of a severe blunt or penetrating trauma to the chest or abdomen that tears a hole in the diaphragm.

The Core Problem in CDH: Underdeveloped Lungs

In CDH, the hole in the diaphragm allows the organs from the abdomen such as the stomach, intestines, and sometimes even the liver to migrate up into the chest cavity.

• A helpful analogy is to think of the chest and abdomen as two separate rooms in a house, separated by a strong, muscular floor (the diaphragm).
• The chest is the nursery, where the delicate lungs are meant to have plenty of protected space to grow and develop. The abdomen is the kitchen, filled with bulky appliances like the intestines and stomach.
• In congenital diaphragmatic hernia, it is as if a large hole was left in the floor of the nursery during construction.
• The bulky kitchen appliances push up through this hole, crowding the nursery. This has two potentially devastating effects:
  • The nursery becomes so crowded that the lungs have no room to grow. They remain small and underdeveloped, a condition called pulmonary hypoplasia.
  • The blood vessels within these underdeveloped lungs also develop abnormally, leading to high blood pressure in the lungs (pulmonary hypertension) after birth.

It is critical to understand that the main life-threatening problem in CDH is not the hole in the diaphragm itself, which is surgically repairable. The true danger comes from the underdeveloped lungs and pulmonary hypertension, which determines the baby’s ability to breathe after birth.

The cause of congenital diaphragmatic hernia is a failure of the diaphragm to close properly during the early weeks of fetal development. In the vast majority of cases, the exact cause of this developmental error is unknown. It is believed to be a multifactorial condition, meaning it likely results from a complex combination of genetic and environmental factors. It is not caused by anything the parents did or did not do during pregnancy.

The cause of an acquired diaphragmatic hernia is a severe physical trauma that tears the muscle of the diaphragm.

In my experience, families are often shocked when a newborn is diagnosed with a diaphragmatic hernia, especially if it wasn’t detected during pregnancy.

CDH is a congenital condition that a baby develops in the womb.

• It is not contagious.
• Sporadic Nature: In most cases, CDH is a sporadic, random event with no prior family history.
• Genetic Component: In some cases, CDH can be associated with an underlying chromosomal abnormality or can be part of a broader genetic syndrome. For this reason, genetic testing is often recommended when a diagnosis of CDH is made.

In my experience, although rare, traumatic diaphragmatic hernias can occur in adults due to blunt abdominal trauma, such as from car accidents or falls.

The signs and symptoms depend on whether the hernia is congenital or acquired.

Signs of CDH in a Newborn

A baby born with a significant CDH will be in severe respiratory distress from the moment of birth. This is a true neonatal emergency.

• Severe Difficulty Breathing: This includes very rapid breathing (tachypnea), grunting sounds with each breath, and retractions (a visible sucking in of the chest muscles).
• Cyanosis: A bluish discoloration of the skin, lips, and fingernails due to a profound lack of oxygen.
• Scaphoid Abdomen: The baby’s abdomen may look sunken or flat (“scaphoid”) because many of the abdominal organs are located up in the chest.
• Barrel-Shaped Chest: The chest may appear large and barrel-shaped.
• When listening with a stethoscope, a doctor may hear bowel sounds in the chest and will hear decreased or absent breath sounds on the affected side (most commonly the left side).

In newborns, I often see severe respiratory distress, a scaphoid abdomen, and decreased breath sounds, it’s a neonatal emergency requiring immediate attention.

Signs of an Acquired Diaphragmatic Hernia

In an adult or child who develops a hernia after a trauma, the symptoms may include chest pain, abdominal pain, and shortness of breath.

Prenatal Diagnosis

Thanks to modern ultrasound technology, the vast majority of congenital diaphragmatic hernias are now diagnosed before birth, during a routine mid-pregnancy anomaly scan.

• Ultrasound Findings: A sonographer will see the tell-tale signs of CDH, such as the stomach or loops of bowel present in the chest cavity, and the heart being pushed over to the opposite side.
• Further Evaluation: Once CDH is suspected, the mother will be referred to a maternal-fetal medicine specialist for a detailed, high-level ultrasound and a fetal echocardiogram to assess the baby’s heart. A fetal MRI may also be performed to get a more detailed look at the organs and to help estimate the lung volume, which is a key predictor of outcome.
• A prenatal diagnosis is invaluable. It allows the parents to receive extensive counseling and to create a plan to deliver the baby at a specialized tertiary care center that has a high-level Neonatal Intensive Care Unit (NICU) and an experienced pediatric surgical team.

Postnatal Diagnosis

If the CDH is not detected before birth, it is diagnosed immediately in the delivery room based on the signs of severe respiratory distress. A chest X-ray will be performed right away and will clearly show the abdominal organs within the chest, confirming the diagnosis.

In my experience, prompt imaging in symptomatic newborns or trauma patients is critical. Delay in diagnosis can worsen prognosis due to progressive respiratory compromise.

The management of a newborn with CDH is a neonatal emergency that requires immediate, highly specialized care in a Level IV NICU with a team of neonatologists, pediatric surgeons, and respiratory therapists.

The “Stabilize First, Operate Later” Approach

The modern approach to treating CDH is to focus first on stabilizing the baby’s fragile lungs and heart. Surgery to repair the hole is delayed until the baby is stable enough to tolerate the procedure.

Immediate Stabilization:

• Intubation: Immediately after birth, a breathing tube is placed into the baby’s windpipe, and they are connected to a mechanical ventilator (a breathing machine) to support their underdeveloped lungs. A tube is also placed into the stomach to remove air and decompress the intestines.
• NICU Care: The baby is transferred to the NICU, where the team works to manage the pulmonary hypertension. This involves specialized ventilator strategies and medications to help relax the blood vessels in the lungs.
• ECMO (Extracorporeal Membrane Oxygenation): For the most critically ill babies whose lungs and heart cannot be supported by a ventilator alone, a heart-lung bypass machine called ECMO may be used. ECMO takes over the work of the heart and lungs, allowing these delicate organs to rest and recover before surgery.

Surgical Repair:

• Surgery is typically performed once the baby’s lung function and blood pressure have stabilized, which may be several days after birth.
• A pediatric surgeon will make an incision in the abdomen, gently guide the stomach, intestines, and other organs down from the chest and back into their proper position in the abdomen.
• The surgeon will then close the hole in the diaphragm. If the hole is small, it may be stitched closed directly. More commonly, a synthetic patch is needed to cover the large defect.

Experimental Fetal Surgery

For fetuses with the most severe forms of CDH, an experimental in-utero procedure called FETO (Fetoscopic Endoluminal Tracheal Occlusion) may be offered at a very small number of specialized centers.

Clinically, long-term management may involve nutritional support, respiratory therapy, and monitoring for complications like pulmonary hypoplasia or gastroesophageal reflux.

A prenatal diagnosis of congenital diaphragmatic hernia is a devastating and frightening piece of news for expectant parents. It marks the beginning of a journey filled with medical uncertainty and significant challenges. The condition is life-threatening, and the outcome depends almost entirely on the degree of the baby’s lung development and the availability of highly specialized neonatal intensive care and expert pediatric surgery. However, the story of CDH is also one of incredible medical progress. The development of advanced ventilation strategies, the use of ECMO, and the refined “stabilize first” surgical approach have dramatically improved survival rates over the last few decades. Clinically, I advise close prenatal monitoring if a diaphragmatic hernia is suspected during pregnancy, as specialized delivery and surgical planning can significantly improve outcomes.

1. The Centers for Disease Control and Prevention (CDC). (2024). Facts about Congenital Diaphragmatic Hernia (CDH). Retrieved from https://www.cdc.gov/ncbddd/birthdefects/cdh.html
2. National Institutes of Health, Genetic and Rare Diseases Information Center (GARD). (2021). Congenital diaphragmatic hernia. Retrieved from https://rarediseases.info.nih.gov/diseases/6257/congenital-diaphragmatic-hernia
3. Children’s Hospital of Philadelphia (CHOP). (n.d.). Congenital Diaphragmatic Hernia (CDH). Retrieved from https://www.chop.edu/conditions-diseases/congenital-diaphragmatic-hernia-cdh