Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CHD) occurs when the diaphragm – the muscle separating the chest from the abdomen – does not develop properly and creates a small opening, allowing the abdominal organs to move into the chest cavity where they compress the lungs and prevent them from growing properly (a condition called lung hypoplasia). This can lead to breathing difficulties once the baby is born.

While the exact cause of CDH is unknown, it occurs early in the development of the fetus (nine to 10 weeks of gestation) and affects approximately one in 2,200 live births.

During pregnancy, CDH can be detected from an ultrasound if the baby’s stomach is seen within the chest cavity and the heart is displaced. A fetal MRI can also confirm the diagnosis. In some cases it may only be diagnosed after the baby is born.

While 50-60% of babies with CDH do not have any other malformations, CDH may be associated with other problems including heart abnormalities and genetic or chromosomal abnormalities.

If a diagnosis of CDH is suspected, your obstetrician or primary care physician should refer you to the Fetal Diagnosis and Treatment Group at the McGill University Health Centre (MUHC). You will be seen by many experienced CDH specialists (maternal-fetal medicine specialists, neonatologists, pediatric cardiologists, pediatric surgeons, and geneticists) as part of a comprehensive prenatal diagnosis and management program.

A high-resolution ultrasound and MRI will confirm the diagnosis of CDH. Additional tests will also be performed to search for potential problems with the chromosomes (amniotic fluid or blood tests) or the heart (fetal echocardiogram).

To follow the progress of your pregnancy, you will be scheduled for regular appointments and ultrasounds. For quick access to specialist care in neonatology and surgery, arrangements will be made to have you deliver your baby at the MUHC.

Babies with CDH are placed on a special breathing machine (called a ventilator) immediately after birth. They will be transferred to the Neonatal Intensive Care Unit at the Montreal Children’s Hospital where they will be cared for by a specialized team of doctors, nurses and respiratory therapists.   

CDH is treated with surgery, by using either the baby’s own diaphragm muscle if the hole is small, or with an artificial patch if the hole is large. The timing of the surgery depends on how well the baby is doing. Surgery may occur within 24-48 hours after birth if the baby is well and shows good lung development, but often it takes several days until the baby is stable enough for the procedure.

Sometimes, babies with CDH may be medically unstable after birth. In these situations, special ventilators and medications may be used to help keep the baby’s oxygen and blood pressure in a normal range. For the most critically ill babies, a special “heart-lung” bypass machine (extra-corporeal membrane oxygenation or ECMO) may be required to provide the baby with enough oxygen. In these cases, surgery may be delayed until the ECMO machine is removed. 

Once discharged from the hospital, many CDH babies do well, but a third of them may continue to have ongoing issues during infancy and childhood with breathing, feeding, growth and development.

You and your child will be followed by the multidisciplinary Congenital Diaphragmatic Hernia Clinic at the Montreal Children’s Hospital, the only clinic of its kind in Quebec. This specialized clinic follows patients from infancy through to late adolescence and includes a respirologist, a gastroenterologist, a dietician, a nurse, a pediatrician specialized in development, and a pediatric surgeon. Other specialists may also be consulted as needed. The CDH team will share the results from your clinic visits and their recommendations for follow-up care with your family doctor or pediatrician.