The diaphragm is a muscle that separates the chest from the abdomen. It forms between the fourth and eighth weeks of fetal development. In some babies, the diaphragm fails to close, leaving behind a hole. This is called a congenital diaphragmatic hernia, or CDH.

The hole in the diaphragm varies in size. If the opening is large enough, developing abdominal organs (such as the intestines, liver, stomach and spleen) can push through the hole into the chest cavity. The extra organs crowd the chest and limit the ability of the lungs to grow and develop. There are fewer arteries supplying blood to the lungs, and the blood vessels that develop tend to be more muscular and thicker than normal. This leads to high pressure within the lung's arteries. After birth, the extra force in the lung arteries inhibits the flow of blood into the lungs and interferes with the ability to take in oxygen and release carbon dioxide.

According to the organization, CHERUBS, a congenital diaphragmatic hernia occurs in about one out of the every 2,500 births. In 80 percent of cases, the hernia occurs in the left side of the diaphragm.

A baby born with CDH may have difficulty breathing and have a bluish skin tint (from a lack of oxygen). The heart rate may be extremely fast. The abdomen may appear flat (because the abdominal organs are pushed into the chest). Up to 25 percent of babies with CDH have other congenital abnormalities, most commonly heart defects.

Survival and Treatment

Thirty years ago, the survival rate for babies with CDH was 50 percent. However, better treatments and the ability to detect some cases before birth have increased the chance of survival to 80 percent or higher.

CDH can be surgically repaired. However, doctors typically wait until the baby's lung function begins to improve. Initially, a tube may be placed in the stomach to keep air out of the intestines and reduce pressure from the intestines on the lungs. A ventilator provides low pressure oxygen to the lungs. If the baby still doesn't get enough oxygen, doctors may use extracorporeal membrane oxygenation (ECMO, a type of heart-lung bypass machine for babies).

The Surgical Fix

The traditional surgery for CDH involves making a large incision into the chest or abdomen. The protruding abdominal organs are removed from the chest cavity and placed in their proper position. If the opening in the diaphragm is small enough, the surgeon can pull the ends and hold them together with stitches. For larger openings, a surgical patch is sutured over the hole.

Some physicians are now using a laparoscopic approach to repair a CDH. Kathleen Graziano, M.D., Pediatric Surgeon with Phoenix Children's Hospital, explains a few small incisions are made between the ribs. Then, a viewing scope and tiny surgical instruments are placed through the incisions. Using a camera on the scope for visual guidance, doctors move the abdominal organs out of the chest and into the abdominal cavity. The hole in the diaphragm is then closed.

Graziano says the smaller incisions mean less trauma for the baby and an easier recovery. Currently, there are only a few physicians around the country who are performing the laparoscopic CDH repair.

For general information on congenital diaphragmatic hernia:

American Pediatric Surgical Association

CHERUBS: The Association of Congenital Diaphragmatic Hernia Research, Advocacy and Support

"Congenital Diaphragmatic Hernia," Northbrook: American Pediatric Surgical Association, downloaded from website