Congenital diaphragmatic hernia (CDH) is a birth defect in which the diaphragm—the muscle that separates the abdomen from the chest—does not develop completely. This causes a hole where abdominal organs can migrate into the chest. When that happens, it doesn’t leave enough space for the lungs to develop normally, making it hard for the baby to breathe.

CDH is typically found at the 20-week ultrasound. CDH affects about one in every 2,500 to 3,000 pregnancies - a relatively high frequency for a birth defect. Similar to that of spina bifida and cystic fibrosis.

The name refers to the location of the hole in the diaphragm. Left-sided CDH is the more common form and frequently results in less severe outcomes. Right-sided CDH tends to be more severe due to the liver’s ability to herniate up into the chest cavity, greatly reducing lung capacity.

Both ECMO (Extracorporeal Membrane Oxygenation) and FETO (Fetoscopic Endotracheal Occlusion) are medical interventions the may be used for the treatment of CDH.

ECMO is a life-support technique that functions as a heart-lung machine, temporarily taking over the work of the heart and lungs. Blood is pumped outside the body to the machine, where carbon dioxide is removed and oxygen is added before being warmed and returned to the body. This process allows the heart and lungs to rest and heal.

FETO is an in-utero procedure used only in the most severe CDH cases. Performed between 27–31 weeks of gestation, it involves threading a small balloon down the baby’s trachea to temporarily block fluid from leaving the lungs. The goal is to trap fluid and build pressure, stimulating lung growth before birth. The balloon is removed before delivery, and the delivery process may differ based on the severity of the CDH.

Each CDH case varies greatly. In some instances, the hole in the diaphragm is small, allowing only a limited portion of the intestine to shift into the chest. In more severe cases, a larger opening may permit multiple abdominal organs—such as the intestine, stomach, spleen, and liver—to move into the chest cavity.

The extent of organ migration directly impacts lung development, determining whether the lungs are moderately small or severely underdeveloped. While CDH presents significant challenges, experience has shown that the majority of affected infants have enough lung capacity to survive. However, those with severely small lungs require expert medical management for the best chance of survival.

Just like the initial diagnosis, the long-term prognosis for a child with CDH can vary significantly. Some children go on to lead relatively active lives, while others may experience chronic lung disease, delayed respiratory issues, or even full oxygen dependency.

Every case is unique, making open communication with your care team essential. Rather than focusing on the “what ifs,” rely on your medical team for guidance tailored to your child’s specific needs.

For additional insights, the blog Raising Diaphragmatic Children - though no longer active - contains valuable information on potential challenges, such as reherniation, bowel obstruction, lung disease, and difficulties with weight gain.