Congenital diaphragmatic hernia, or CDH, is a condition that develops before birth. Babies with CDH have a hole in their diaphragm, the wide, flat muscle that separates the chest from the abdominal cavity. Normally, the diaphragm forms during the 6th through the 12th week of pregnancy. If the diaphragm doesn't form completely, CDH occurs. Most often, the defect is on the left side. CDH affects about one in every 2,500 births.
The hole in the diaphragm allows the contents of the abdomen — which may include the stomach, intestine, liver, spleen or kidney — to herniate up into the chest. These abdominal organs occupy space in the chest and prevent the lungs from growing to normal size. The growth of both lungs can be affected. This is called pulmonary hypoplasia. While in the uterus, a fetus doesn't need lungs because oxygen is delivered through the mother's placenta. Once the baby is born, healthy lungs are necessary.
There is a wide range in the severity of CDH. In the best cases, some infants do very well with neonatal care and surgical treatment after birth. On the other end of the spectrum, babies with severe CDH will have a difficult struggle after birth, and some will not survive. Even when the CDH is severe, however, more than 70 percent of affected babies can be saved with intensive support. Some may be candidates for prenatal intervention. The UCSF Fetal Treatment Center was the first facility in the world to offer treatment for congenital diaphragmatic hernia while a baby is still in the womb.
Experts at the UCSF Fetal Treatment Center have compiled a free patient guide book about CDH. The book is available for download on iPads with iBooks 2 or on computers with iTunes. To download, visit iTunes.
CDH is typically diagnosed before birth during routine screening tests. An ultrasound may show abdominal contents in the chest cavity.
After birth, symptoms of congenital diaphragmatic hernia may include:
CDH is usually diagnosed before birth during routine screening tests. After the initial diagnosis, it is important to have an expert assess your fetus to determine the severity of the defect. Knowing the severity is important for determining the best treatment options.
The two factors used to grade the severity of CDH are the position of the liver and the lung-to-head ratio. Liver position refers to whether or not any portion of the liver has herniated, or moved up into the chest. Fetuses with a portion of the liver in the chest have a more severe condition.
The lung-to-head ratio is a numeric estimate of the size of the lungs based on measuring the amount of visible lung. High lung-to-head ratios are associated with good outcomes.
Fetuses on the most severe end of the spectrum, with liver up into the chest and a lung-to-head ratio less than 1.0, may be candidates for prenatal intervention.
There is a wide range of severity and outcomes for CDH. In the best cases, some infants do very well with routine neonatal care and surgical treatment after birth. Even though the lung isn't of normal size at birth, it has the capacity to grow and adapt for many years, so these children can lead normal, active lives without restriction.
On the other end of the spectrum, babies with severe CDH and very small lungs are guaranteed to have a difficult struggle after birth, and some will not survive. Even when the CDH is severe, however, more than 70 percent of affected babies can be saved with intensive support. However, there are often long-term health issues related to breathing, feeding, growth, hearing and development.
Most babies with CDH fall somewhere in between these extreme ends of the spectrum.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
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