Congenital Diaphragmatic Hernia (CDH)
Updated: May 30, 2019
Let’s talk about CDH. In my previous blog post, Daniel’s birth story, I briefly touched on what CDH exactly is. I could not find any South African research or statistics, so most of the information in this post is from the U.S.A. The reason for this post is to shed some light on this rare condition and hopefully increase awareness around it. As new parents we had no idea what we were facing, and a blog post like this could have been very helpful to us in our darkest hour. Even if Daniel’s story only helps one mommy or daddy, my heart will be grateful.
Just to recap from my previous post, our little boy was born with a congenital diaphragmatic hernia on 26 April 2018. We had no idea he had this condition, we found out at his birth, so it was quite a shock and very traumatic. If you have not read his birth story yet, you can do so here.
What is congenital diaphragmatic hernia (CDH)
Source: UCSF Fetal Treatment Center
About 1,600 babies are born with CDH every year in the U.S, or 1 in every 2,500 babies. A Congenital diaphragmatic hernia occurs when the diaphragm muscle — the muscle that separates the chest from the abdomen — fails to close during prenatal development.
The wide, flat muscle that separates the chest and abdominal cavities is called the diaphragm. The diaphragm forms when a fetus is at 8 weeks gestation. When it does not form completely, a defect, called a congenital diaphragmatic hernia (CDH), is created. This is a hole in the muscle between the chest and the abdomen.
The majority of CDH’s occur on the left side, which is where Daniel’s was. The hole allows the contents of the abdomen (stomach, intestine, liver, spleen, and kidneys) to go up into the fetal chest. With Daniel, his bowls migrated up through the hole and was positioned on top of his left lung. This resulted in his left lung moving to the middle of his chest (where his heart should be), which then made his heart and right lung move all the way up towards his right shoulder. Resulting in all his vital organs being misplaced. This also meant that his left lung could be vitally underdeveloped. The herniation of these abdominal organs into the chest occupies that space and prevents the lungs from growing to normal size. The growth of both lungs can be affected. The result of this is called pulmonary hypoplasia.
While in the uterus, a fetus does not need its lungs to breathe, because the placenta performs this function. However, if the lungs are too small after the baby is born, the baby will not be able to provide itself with enough oxygen to survive.
What is the Outcome for a Baby with CDH?
There is a wide range of severity and outcomes for CDH. In the best cases, some babies do very well with treatment after birth, surgery and care in the NICU. In the most severe cases, some will not survive no matter how hard we try. And in the middle, some will live normally while others will have a difficult time and may have some handicaps ranging from mild learning problems to breathing and growth problems. How the baby does after birth is determined by how well the lung grows before birth and its function.
Thankfully Daniel’s left lung was not as underdeveloped, this could be due to the fact that his hernia occurred very late in utero. Which meant his left long had enough time to develop normally. This was a miracle and God sent.
Babies on the best end of the spectrum have an excellent chance to lead a perfectly normal life, as we pray Daniel will do. They do not require special prenatal management in terms of the timing or type of delivery, but should be delivered in a perinatal center with a Level III intensive care nursery with neonatal and pediatric surgery support. The place of delivery is very important because transporting these babies after birth can be dangerous for the infant. Babies still need to have the diaphragm hole repaired after birth and will be in the intensive care nursery for several weeks. 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 can have difficult challenges after birth, and some will not survive. These babies require very skilled intensive care to stay alive—things like high-frequency or oscillatory ventilation, inhaled nitric oxide and, in some cases, extracorporeal membrane oxygenation (ECMO). ECMO provides temporary support for lung failure by circulating the baby’s blood through a heart-lung type machine. It can be life-saving but can be used for only limited time.
The surgery to repair diaphragmatic hernia after birth is not an emergency and is usually performed when the baby has stabilized, usually within the first week of life. Daniel had his surgery when he was three days old. After repair, these babies will need intensive support for many weeks or even months. Even when the CDH is severe, greater than 70% of affected babies can be saved with intensive support. However, there can be long term health issues related to breathing, feeding, growth and development.
Causes of Congenital diaphragmatic hernia (CDH)
Source: Genetics Home Reference
While we don’t know exactly what causes a CDH, from my research I found the following – we fall into number 3 & 4:
1.) In 10 to 15 percent of affected individuals, the condition appears as a feature of a disorder that affects many body systems, called a syndrome. Donnai-Barrow syndrome, Fryns syndrome, and Pallister-Killian mosaic syndrome are among several syndromes in which CDH may occur.
2.) About 25 percent of individuals with CDH that is not associated with a known syndrome also have abnormalities of one or more major body systems. Affected body systems can include the heart, brain, skeleton, intestines, genitals, kidneys, or eyes.
3.) Approximately 50 to 60 percent of CDH cases are isolated, which means that affected individuals have no other major malformations.
4.) More than 80 percent of individuals with congenital diaphragmatic hernia have no known genetic syndrome or chromosomal abnormality. In these cases, the cause of the condition is unknown.
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 NICU 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 NICU can vary widely depending on your child’s response to treatment. Daniel’s stay in hospital was 6 weeks and he went home on oxygen.
As babies receive this comprehensive medical care, social workers and psychologists help support family members through all the ups and downs you experience.
In addition to surgical repair, a CDH baby may require specialized equipment such as the oscillator ventilator, heart lung machine (ECMO) or nitric oxide, Daniel had all of the above.
From all the technical information and medical jargon above you can see how lucky our boy truly is. CDH is a severe and life-threatening condition and things could have gone very differently for our little Daniel. But he survived and excelled with flying colours. All his doctors called him their miracle baby. And to us that is what he is. A miracle. A testimony of God’s grace. An answer to so many prayers. We serve an almighty God and all glory and thanks goes to Him.