Congenital Diaphragmatic Hernia (CDH)

CDH is primarily a problem of 'space.' In a typical pregnancy, the diaphragm forms a solid barrier, allowing the lungs to expand freely. In CDH, a failure in this development—usually on the left side (85% of cases)—creates a gateway. organs like the intestines, stomach, and even the liver can migrate into the thoracic cavity.

When these organs reside in the chest, the developing lungs are physically compressed. This doesn't just make the lungs smaller; it changes their internal structure, making the blood vessels within the lungs thicker and harder to breathe through (pulmonary hypertension). The challenge is not the hole itself—which is surgically closed after birth—but ensuring the lungs are robust enough to support life immediately after delivery. We use high-resolution ultrasound and sometimes fetal MRI to map exactly which organs have moved and how much space remains for the lungs.

CDH occurs in approximately 1 in 2,500 live births. It is a sporadic condition, meaning it usually happens by chance rather than being inherited through family genetics.

While most cases are 'isolated' (meaning the CDH is the only issue), approximately 30-40% of babies may have associated concerns, such as heart defects or chromosomal variations (like Trisomy 18 or 13). Because the presence of an additional condition significantly changes the management plan and the success rate of fetal surgery, we strongly recommend a detailed anatomy survey and genetic testing (Amniocentesis with Microarray) for every CDH diagnosis. Our Unit provides a single, unified point of care for these complex assessments.

The severity of CDH is what dictates the prognosis. We use the Observed to Expected Lung-to-Head Ratio (O/E LHR) as our primary diagnostic metric. By measuring the area of the healthy lung and comparing it to the size of the baby's head, we can categorize cases into:

• Mild CDH: O/E LHR above 45%. These babies usually have an excellent prognosis with standard postnatal care.
• Moderate CDH: O/E LHR between 25% and 45%.
• Severe CDH: O/E LHR below 25%. These babies are the primary candidates for fetal intervention.

We also look for the liver position. If the liver has moved into the chest ('liver-up'), the risk is higher than if the liver remains in the abdomen. Our subspecialists use international protocols (the TOTAL trial standards) to ensure your baby is categorized with absolute precision, ensuring the right treatment is offered at the right time.

Management at the MFM Unit represents the pinnacle of modern fetal medicine. For moderate to severe cases, we offer Fetoscopic Endoluminal Tracheal Occlusion (FETO):

1. The Window (27-29 Weeks): Under local anesthesia, we use a microscopic fetoscope to enter the amniotic sac.
2. The Balloon: We place a tiny, detachable balloon inside the baby's trachea (windpipe).
3. Biological Growth: By blocking the trachea, we trap the fluid naturally produced by the lungs. This internal pressure 'stretches' the lung tissue from the inside out, forcing it to grow rapidly and fill the chest cavity, pushing organs back down.
4. Removal (34 Weeks): The balloon is safely removed before birth, allowing the lungs to mature for delivery.

All CDH babies must be delivered at a tertiary center like Mediclinic, where pediatric surgeons and advanced NICU ventilation (like ECMO) are available 24/7. We coordinate every step of this journey, from the first puncture to the final surgical repair after birth.

The outlook for CDH has been transformed by subspecialty care. In the past, babies with severe CDH had very low survival rates. Today, with the FETO procedure and advanced neonatal care, we can double the survival chances for many of these infants.

• Survival: For cases managed by an expert multidisciplinary team, survival now ranges from 70% to 90% depending on the severity.
• Postnatal Life: Following delivery, the baby will typically require a few days of stabilization before a pediatric surgeon closes the diaphragm. While some children may face initial feeding challenges or respiratory sensitivity, the majority grow up to lead healthy, active lives. Our goal is to move beyond 'survival' to ensure your child has the highest possible quality of life.

Time is of the essence in a CDH diagnosis. The optimal window for the FETO procedure is between 27 and 29 weeks of pregnancy. If you are diagnosed at 20 weeks, you have a crucial window to have your O/E LHR measured and a management plan established.

If you have been told your baby has a diaphragmatic hernia, you should request an immediate referral to the Maternal Fetal Medicine Unit. We provide the secondary expert opinion needed to confirm the severity and determine if FETO is appropriate. Our team, led by Dr. Werner Diehl, is one of the few in the region with the accreditation and experience to perform these complex fetoscopic procedures. Early referral is the best way to ensure the full range of life-saving options remains open to your family.