Congenital Diaphragmatic Hernia (CDH)
What is congenital diaphragmatic hernia (CDH)
Congenital diaphragmatic hernia (CDH) occurs when the diaphragm muscle — the muscle that separates the chest from the abdomen — fails to close during prenatal development, and the contents from the abdomen (stomach, intestines and/or liver) migrate into the chest through this hole.
About 1,600 babies are born with CDH every year in the U.S., or 1 in every 2,500 live births. The same number of babies are born with cystic fibrosis or spina bifida.
When the abdominal organs are in the chest, there is limited room for the lungs to grow. This prevents the lungs from developing normally, resulting in pulmonary hypoplasia (or underdeveloped lungs). This can cause reduced blood flow to the lungs and pulmonary hypertension (high blood pressure in the pulmonary circulation), as well as asthma, gastrointestinal reflux, feeding disorders and developmental delays.
CDH can occur on the left side, right side or, very rarely, on both sides. It can be life-threatening.
Evaluation and diagnosis
After a doctor has diagnosed CDH in a pregnancy, the next step is to be referred to a prenatal diagnosis center for additional testing and information. If a patient is referred to our Center for Fetal Diagnosis and Treatment (CFDT), a comprehensive multidisciplinary evaluation will be scheduled.
Upon arrival to our Center, you will be greeted by one of our nurse coordinators or genetic counselors. The coordinator will review any questions you may have, discuss the schedule for the day, and provide a tour of CHOP’s Garbose Family Special Delivery Unit and the Harriet and Ronald Lassen Newborn/Infant Intensive Care Unit (N/IICU).
The day of your fetal consultation will include a variety of diagnostic tests and a meeting with a genetic counselor to review family history and prenatal genetic testing.
High resolution ultrasound
A high resolution ultrasound is performed by our sonographers and fetal radiologists and often lasts up to two hours. The ultrasound will confirm the diagnosis and the side of the hernia, identify any additional malformations, determine lung size, and calculate a lung-to-head ratio (LHR) and an observed over expected ratio (O/E). The ultrasound also determines the position of the liver, which is very important. (For clinicians: CDH diagnostic tool)
A fetal echocardiogram or targeted ultrasound of your baby’s heart is performed by our fetal cardiologist. The fetal echo determines if there are any structural defects of the heart. It can sometimes be difficult to perform when the abdominal organs are in the chest causing the heart to be compressed.
Ultrafast fetal MRI
An ultrafast fetal MRI, a technique pioneered at CHOP, provides further anatomy detail regarding the liver position. Large amounts of liver in the chest and an O/E less than 25 percent based on MR volumes is considered a severe CDH.
Once the diagnostic exams are complete, you will meet with a high-risk maternal-fetal medicine specialist (MFM), a pediatric surgeon and your coordinator to review the results of all exams and confirm your baby’s diagnosis. At this time, we will discuss all treatment options and prenatal and postnatal care, as well as delivery recommendations. Our team will answer any questions your family has and provide educational information about CDH for you to take home.
Prenatal management of CDH
In consultation with your doctor, our team will closely monitor your pregnancy, with frequent exams especially in the last trimester. This close monitoring will help us determine if it is necessary to deliver early, or if you and your baby may be candidates for fetal intervention.
Follow-up ultrasound exams should be performed every four weeks throughout the pregnancy to evaluate your baby’s growth and activity. If you live far away, these ultrasounds can be performed at your local doctor’s office. At 34 weeks, ultrasounds increase to weekly.
At this time, relocation to one of our Ronald McDonald Houses is necessary if you live more than one hour away from our Center. You will need to relocate sooner if you undergo prenatal intervention, if extra fluid develops around your baby (polyhydramnios), or if there are signs of preterm labor. This will ensure that you are nearby in the event labor occurs earlier than expected.
The severity of congenital diaphragmatic hernia (CDH) is largely determined by the position of the liver. Outcomes are generally better in cases where the liver remains down in the abdomen and the LHR is higher. The overall survival rate is 70 percent.
Delivery of babies with CDH
The health of a baby born with CDH can change unexpectedly, making it critically important to deliver within the hospital where postnatal care will be received and have all aspects of specialized care immediately available in one location.
The majority of babies with CDH can be delivered vaginally. However, there is a low threshold for performing a C-section delivery for fetal indications. If a woman has any maternal health issues, delivery at the adjacent Hospital of the University of Pennsylvania will be arranged.
If mom and baby meet the qualifications, a vaginal delivery at term is planned in our Garbose Family Special Delivery Unit (SDU), which was created specifically for the healthy mother whose pregnancy is affected by a birth defect. At delivery, your baby is carried to a pass-through window into a room where the Neonatal Surgical Team — including neonatologists, surgical advanced practice nurses, neonatal and surgical fellows, neonatal surgical nurses, and respiratory therapists — is waiting to stabilize your baby and provide any specialized ventilation (breathing) assistance before bringing him to the N/IICU for further care.
At stabilization, a breathing tube is inserted into your baby’s airway so a ventilator can be attached to help with breathing. A tube going from the mouth or nose to the stomach will be placed to keep air from getting into the stomach and intestines causing less space for the lungs to expand. Intravenous and arterial lines will be placed in blood vessels of your baby’s arms, legs or belly button for administration of fluids and medications. Blood gases will be drawn from the arterial line to assess how well your baby can oxygenate. The neonatal team at CHOP has extensive experience in ventilation techniques for babies with CDH.
Treatment for congenital diaphragmatic hernia
For babies born with CDH, every little detail matters and can impact the outcome. It is important that your baby be treated by a team with experience caring for babies with CDH.
At CHOP, we see nearly 50 babies every year with CDH — more than anyone in the U.S. Our Neonatal Surgical Team is the only team of its kind in the world, working together since 2004. Your baby will be cared for using optimal care guidelines developed by our experienced multidisciplinary team.
In addition to surgical repair, your baby may require specialized equipment such as the oscillator ventilator, heart lung machine (ECMO) or nitric oxide, but it is important that they have immediate access when necessary.
Fetal surgery for severe CDH
For babies with the most severe cases of CDH, treatment before birth may allow the lungs to grow enough before birth so these children are capable of surviving and thriving. Fetoscopic endoluminal tracheal occlusion (FETO) is a fetal surgery procedure that may improve outcomes in babies with the most severe cases of CDH.
As part of a clinical research study approved by the U.S. Food and Drug Administration (FDA), Children’s Hospital of Philadelphia is offering FETO as a treatment option to select fetuses with severe CDH. Learn more about what to expect if you and your baby are a candidate for FETO.
After FETO, mothers remain in Philadelphia until planned delivery in the Special Delivery Unit. After your baby is born, she will be stabilized in the Newborn/Infant Intensive Care Unit (N/IICU). Once stabilized, she will undergo the traditional postnatal surgery to repair the hole in her diaphragm.
After delivery, babies with severely compromised or fragile lungs may require extracorporeal membrane oxygenation (ECMO), a temporary heart-lung bypass technique used to oxygenate the blood and allow the lungs to rest.
Under sterile conditions at the bedside and once your baby has received pain medication, the pediatric surgeon will place two tubes called cannulas into the artery and vein in your baby’s neck.
The tube in the neck takes blood out of the body from the large vein, oxygenates the blood through the ECMO circuit and returns the now oxygenated blood to the baby by the carotid artery.
ECMO is used when other treatments are unsuccessful. The lungs rest as the ECMO circuit does the work. In some cases the baby may have the CDH repair while on ECMO.
Excellence in ECMO
ECMO can have serious complications including bleeding and infection. Careful monitoring by an experienced ECMO specialist is critical. At CHOP, one ECMO specialist and an experienced neonatal surgical registered nurse oversee care at all times.
CHOP has been designated a Center of Excellence by the Extracorporeal Life Support Organization since 2008. Our program has done more than 1,000 ECMO treatments since beginning in 1991, with the team providing ECMO support to nearly 150 CDH babies.
Postnatal surgery for CDH
Surgical repair of CDH after delivery depends on your baby’s progress in the days following birth, and can occur as early as three days of life. Babies with CDH are extremely sensitive to noise and movement, so surgical repair of CDH is often performed in the N/IICU so your baby does not have to be transported to the operating room.
Your baby will receive general anesthesia and will be continually monitored by a pediatric anesthesiologist. An incision is made just below your baby’s rib cage, the organs in the chest are guided back down into the abdomen and the hole in the diaphragm is sewn closed. The space created in the chest allows the lungs to continue to grow; children will continue to grow more air sacs or alveoli through early childhood.
For babies with large defects or completely lacking a diaphragm, the hole is closed with a GORE-TEX® patch or muscle flap. Sometimes the abdominal wall cannot be closed during surgery. In these cases, temporary placement of a silo, mesh or Vacuum Assisted Closure® (VAC) device may be recommended. As your child grows, the condition of the patch will be regularly monitored by doctors to ensure that it remains intact.
Length of stay in the N/IICU can vary widely depending on your child’s response to treatment.
As babies receive this comprehensive medical care, social workers and psychologists help support family members through all the ups and downs you experience.
Long-term follow-up by a team of experts is important to provide the best clinical care to your child. The Children’s Hospital of Philadelphia’s unique Pulmonary Hypoplasia Program (PHP) provides comprehensive, interdisciplinary follow-up care for children with CDH. The team is made up of clinicians from general surgery, developmental pediatrics, pulmonary, cardiology, psychology, nutrition, audiology, social services and others as needed.
The PHP follows over 500 children, most of whom were born with CDH, well into school age. Initial follow-up by the PHP will be arranged when your baby is in the N/IICU. Appointments are tailored to your child’s needs, but typically occur at 6 months, 12 months, 2 years, 4.5 years and 6 years, and then every 2 years thereafter, as needed. Appointments are designed for visits to multiple specialists in one day.
CHOP is the only institution evaluating neurodevelopmental outcomes in children born with CDH so that we can continuously improve care and understand long-term outcomes.