About CDH

What is Congenital Diaphragmatic Hernia?
Generally, the fetus develops a diaphragm at 8 weeks gestation [1].  The diaphragm is a muscle that acts as a separator between the chest cavity and the abdomen.  CDH is a defect where either the muscle doesn't develop, or doesn't develop completely, allowing the contents of the abdomen up into the chest.  About 1 in every 2,500 pregnancies are diagnosed with CDH [2].

A diaphragmatic hernia?  Why is that so dangerous to the fetus?
Because "extra stuff" is allowed up into the chest cavity, essential real estate for other developing organs is occupied.  Often, the heart is pushed over to the right side of the chest.  The real danger is two-fold: 1) the extra pressure put on the blood flow to the lungs and 2) the lungs have difficulty growing.  This is a life threatening condition that requires special treatment.

What determines the severity?
Specialists look at several factors - but some of the most important are:
  1. The Lung-to-Head Ratio (LHR) - Although I can't explain how it is determined, the LHR is usually 1.5 to 2.0 in cases of CDH [3].  The lower the number, the lower the prognosis.  We've learned that the best way to measure the LHR is to have an Ultrafast MRI.
  2. The position of the liver - If the liver is pushing into the chest cavity (usually referred to as "up"), the prognosis is worse - meaning that the hernia is large enough to allow more "stuff" up into the chest.  The position of the liver can usually be seen on an ultrasound.
My fetus has been diagnosed with CDH.  Now What?
The most important step is to verify the diagnosis with a fetal specialist - we definitely recommend going to a hospital that is familiar with this condition.  From our research, we decided to go to Children's Hospital of Philadelphia (CHOP).  They are ranked #1 in the nation for newborn care and they see a high volume of special care cases.  Specialists will conduct several different tests including, but not limited to, an Ultrafast MRI, an amniocentesis and a high-definition ultrasound.  It is important for them to rule out any other possible birth defects.  If other defects are involved, it can alter the plan of care at delivery.

How will this affect delivery?
CDH babies require very special treatment at the time of delivery.  At birth, the neonatal team will need to respond quickly in a Special Delivery Unit.  More and more hospitals are adding these types of facilities - the unit needs to be close in proximity to the location of intensive care.  The baby will require immediate stabilization and, likely, specialized breathing assistance.  Once stabilized, the baby will be transferred to an Infant Intensive Care Unit.  They will constantly monitor the baby's status and, if necessary, put him on ECMO - a temporary technique to oxygenate the blood and give the lungs a rest.  This can last several days or even weeks.  Once stable, surgery will be performed to guide the stomach back into the abdomen, move the heart into the correct position and close the hole in the diaphragm.

What about treatment of the fetus?
Treatment of the fetus is still "experimental."  There are specialists who can perform fetal surgeries.  An example surgery is Tracheal Occlusion.  As we understand it, a remote controlled balloon is placed in the trachea as an obstruction.  It is thought that this somehow actually causes the lungs to grow at a more rapid rate.  Mothers who have this procedure must remain close to the hospital for observation.  The balloon can be deflated before the baby is delivered.

Any treatment of the fetus is tricky.  The womb, by design, is the ideal place for a child to grow and develop.  Attempts to invade this space can cause the body to go in to labor and increase the risk of infection.  As a result, hospitals usually only accept cases that meet specific criteria.  Treatment is very expensive and health insurance may choose not to cover it.

How do children survive all of this?
We have learned that the severity and outcome of CDH varies widely on a case-by-case basis.  Postnatal surgery allows room for the lungs to grow.  We were amazed to find out that a child's lungs can grow until age 8 or 9!  The important thing is that they can stabilize the baby.  After that, it is up to the baby to grow and survive.

How does this affect parents?
All parents we've visited with or read about explain this as a life altering event.  The stay in the hospital may last up to 4 months.  Most specialists will recommend going to the hospital of delivery at 32-36 weeks of gestation.  Babies usually require a lengthy stay at the hospital for postnatal care.  There are high costs associated with travel, food and medical expenses.

More importantly, this takes a great toll on the expecting parents.  It is a shock to find out that something is wrong, let alone the thought of possibly losing a child at birth.  As we are finding out, there are great support groups out there and amazing families who have made it through this journey with strong healthy kids.  We are finding great strength in our friends, family and, most importantly, our father God.

Remember: this is the child's journey...
We are not perfect... At times we are scared and worried for our son.  No parent wants to lose a child.  It is our basic instinct to start asking the "why, how, what" questions.  Why did this happen to our child?  How did this happen? What can we do?  It helps us to refocus when we remember that this is about our son and his story.  As much as we feel the affects of this event, it is our son who must make the journey on his fight for survival.  All we can do as parents is try our best to provide the optimal environment for his care.

[1] http://fetus.ucsfmedicalcenter.org/cdh/
[2] http://www.chop.edu/service/fetal-diagnosis-and-treatment/fetal-diagnoses/congenital-diaphragmatic-hernia-cdh.html
[3] http://www.sonoworld.com/fetus/page.aspx?id=229