Congenital diaphragmatic hernia (CDH) remains an unsolved problem and a frustrating clinical disease for physicians, surgeons and scientists despite decades of research. Although it is a surgically correctable defect, the arrest in development of the lungs prenatally results in unacceptably high rates of neonatal mortality and long-term morbidity for the surviving child.
When a report from European studies found that fetal tracheal occlusion (FETO) might improve neonatal survival in cases with isolated severe CDH, North American Fetal Therapy Network (NAFTNet) led the charge to extend the trial to the United States. Seven fetal centers, including The Fetal Center at Children's Memorial Hermann Hospital, qualified to participate in the clinical trial, called Tracheal Occlusion to Accelerate Lung Growth (TOTAL) for Severe Pulmonary Hypoplasia. The Fetal Center is now accepting patients for evaluation as study participants.
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What is a congenital diaphragmatic hernia (CDH)?
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A CDH occurs when a hole develops in the fetal diaphragm, the muscle separating the chest from the abdomen. The size of the hole can range from very small to a complete absence of the diaphragm. This can occur on the left or right side.
As a result of this hole, abdominal contents enter the chest cavity and the fetal lungs can be compressed and underdeveloped. In addition to small and abnormal lungs, infants with CDH may suffer from abnormalities in the blood vessels of the lung. Newborns typically suffer from breathing difficulties related to their abnormal lungs. Although many infants with CDH only have problems related to the diaphragm and lungs, others may have complications such as developmental problems with the brain, heart, kidneys and bowel. The exact cause of CDH is unknown.
CDH occurs in approximately one of every 2,500 - 5,000 live births with varying degrees of severity. Although most infants are diagnosed prenatally or shortly after birth, a small percentage will be identified later in life or not at all.
What will happen during pregnancy?
Most fetuses diagnosed with CDH require careful prenatal monitoring. A series of ultrasounds will be performed to first confirm the diagnosis of CDH and then to monitor fetal development and growth. Additional tests, including fetal MRI, fetal echocardiogram, and amniocentesis, may be recommended to evaluate the severity of the CDH and to identify possible chromosomal abnormalities. The maternal-fetal team will evaluate the severity of the CDH and help determine the best course of treatment. The Center coordinator will help you during your pregnancy by keeping you in contact with all of the appropriate physicians and specialists as well as coordinating the care for you and your baby before, during, and after delivery.
Will a fetal treatment be required?
Fetal intervention is rarely necessary for CDH. Currently, the only fetal treatment under investigation is blocking the fetal trachea. This causes a backup of the amniotic fluid produced by the lungs in an attempt to distend the lungs and make them grow. This technique (fetal tracheal occlusion) uses fetoscopy and is utilized for the most severe cases of CDH. This fetal intervention for CDH is only available under clinical trial in the United States. The doctors at the Texas Center for Maternal Fetal Treatment can discuss these options with you if your infant qualifies.
What special considerations should be made for delivery?
Type of delivery - The delivery plan should be carefully discussed between the mother and her obstetrician.
Place of delivery - The baby should be delivered at a hospital that is well prepared to handle the intensive care and surgery required of infants with CDH. There should be a neonatal intensive care unit with the capability to provide specialized care such as extracorporeal membrane oxygenation (ECMO) similar to a heart-lung bypass, special mechanical ventilation, and pediatric surgical services.
Time of delivery - There is no reason to intentionally induce early delivery. Most babies will benefit from reaching full gestational maturity.
What will happen at birth?
Babies born with CDH are at high-risk for respiratory distress. Immediately following delivery, doctors will carefully evaluate the baby. A neonatologist (a specialized doctor for high-risk babies) will begin providing breathing support and other necessary care. Depending on the severity of breathing difficulties, the baby may require a breathing tube. The newborn will be transferred to the neonatal intensive care unit for further evaluation and management.
What will happen after delivery?
Most infants will be stable after birth and can be closely monitored. Although breathing difficulties may require mechanical ventilation, the newborn may not require additional support and can be stabilized until surgery. A small group of infants with CDH may continue to develop problems with breathing and problems maintaining heart function and blood pressure. Your baby's doctors will provide many different methods to improve the condition of your baby. In the most severe cases, your newborn may need to be supported by heart-lung bypass (ECMO). Surgical repair of the CDH is not an emergency. In most cases, the pediatric surgeons will wait until the infant is stable and able to handle the stresses of surgery.
The pediatric surgeon will evaluate the baby for surgery, and once he or she has been stabilized for a period of time, surgery will be performed to repair the CDH. In some cases, the baby will stabilize quickly enough to undergo surgery in a few days after delivery. In more severe cases, it may be longer before it is safe to perform the surgical repair. The surgeon will determine the safest time for the surgical repair. Typical hospital stays for a newborn with CDH range from a few weeks to several months.
What are the long-term outcomes and considerations?
Complications and long-term health effects from CDH depend greatly on the severity of the case. Following proper post-delivery care and CDH repair, some babies will mature normally and experience no life-long complications. On the other end of the spectrum, CDH does prove fatal in some instances despite the best efforts of parents and physicians. Most babies, though, will fall between these extremes and experience some long-term respiratory, gastrointestinal, neurological or other health issues ranging from asthma to chronic lung disease to scoliosis. After discharge from the hospital, a team of pediatric specialists will continue to care for the baby.
The Center and Children's Memorial Hermann Hospital are internationally recognized leaders in the care and research of CDH. As the first hospital in Houston to provide ECMO and advanced mechanical ventilation strategies, the integrated multidisciplinary team are experts in the care of infants with CDH. The physicians and specialists offer state-of-the-art neonatal critical care and minimally invasive surgical repair of CDH.
Contact The Fetal Center to make an appointment with a high-risk pregnancy doctor:
Note: This information regarding your condition is meant to be a helpful, informative introduction. Because every newborn is different, this may not be applicable to all cases, especially if there are additional defects. Your team of experts at the Center will provide you with information specific to your pregnancy.