CDH:  Congenital Diaphragmatic Hernia.  It’s a serious birth defect that occurs in 1 out of 2,500 live births.

As it was explained to us and as it has been presented on numerous Children’s Hospital websites, here is how I understand it:

The diaphragm is a muscle that separates the abdominal cavity from the chest.  It’s a divider.  At 8-12 weeks gestation, depending on what you read, this muscle develops and comes together, as it should.  But sometimes it doesn’t.  Nobody knows why, it is random.  There isn’t enough evidence to suggest that it is genetically destined to happen, and it isn’t because of anything the mother or father did or didn’t do.  The diaphragm simply forgets to close.  In 90% of diaphragmatic hernia cases, this happens on the left side.  It’s also more common in girls.

This happens at the same time that everything inside of the fetus is forming and finding their places, and if there’s a hole, sometimes organs will find their way through it.  Sometimes the organ involvement is minimal, sometimes not.  In any case, if there is anything that is supposed to be in the abdominal cavity but is incorrectly located in the chest cavity, it takes up valuable space that the lungs need in order to fully develop. 

When a baby with known CDH is born, he has to be intubated and placed on a ventilator immediately.  Crying can make the hernia worse.  If all techniques of getting him adequate oxygen that way are exhausted, he’ll be placed on <a href=”http://emedicine.medscape.com/article/1818617-overview“>ECMO</a>, which is a whole different monster.  Once a baby with CDH is placed on ECMO, his chance of survival drops to 50%.  ECMO comes with its own set of complications (and ECMO is a complication in and of itself), so we’ll focus on that if things get to that point. 

The thing about hernias is that they don’t repair themselves.  They either get fixed or get worse.  Surgery is necessary to repair the hernia:  Making an incision below his ribs, moving his organs into place, and connecting the tissue of the hernia (or repairing with a patch if there is not enough tissue to connect).  The surgery itself is pretty straightforward, but the issue lies in his ability to maintain adequate oxygen levels.

Even if you move the organs back into place, even if the hernia is repaired perfectly…the lungs still  missed out on valuable development while in the womb.  The months following surgery are dedicated to recovery from surgery as well as ensuring proper oxygen levels.  The average NICU stay after birth is 2-3 months.  Babies with CDH may come home with forms of oxygen assistance if everything else is stable enough.

If you would like to read more about CDH, here are some of the more useful resources I’ve found:

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