Patent Ductus Arteriosus

You can probably tell by the title of this post, but we are going to do our best to explain a condition often found in premature infants (using a pamphlet our doctor gave us). Wish us luck!

Patent ductus arteriosus (PDA) is a condition where a fetal blood vessel, the ductus arteriosus, fails to close after birth. While in the womb, the fetus gets oxygen through the placenta, not from its own lungs. The ductus arteriosus is a vessel present in all babies that allows the fetal blood to bypass the lungs and go directly to the placenta. After birth, this vessel is no longer needed and must close to establish normal blood flow.

When a baby is born and the umbilical cord is cut, the lungs are now needed to supply oxygen, causing the ductus arteriosus to close - usually within the first hours of life. When this vessel does not close, it is referred to as Patent (open) Ductus Arteriosus (PDA). This is very common in premature infants. See the diagram below for a pictorial explanation. The purple vessel in the image on the right is where the PDA is located (seen in red).




The doctors first suspected PDAs in both Max and Tyler when they heard heart murmurs a few days after birth. They did chest x-rays, which showed very small PDAs in both boys. Because the PDAs were so small and the anticipated treatment is not without side effects, they decided to wait a week to see if they closed on their own. Additional x-rays last week showed the PDAs were still present, so the doctors decided to start treatment.

The boys were given 3 doses of Indomethacin (yes, the same medication I was given to stop labor 2 days before they were born) for treatment of the PDAs. This medication constricts blood vessels in the body, which would hopefully close the PDA. Because it has an effect on all blood vessels, including those in the kidneys and stomach, the boys' feedings were stopped for 48 hours. As of Friday, the doctors could not longer hear the heart murmurs, which is a good sign that the PDAs responded to treatment and are now closed. They will continue to listen to the boys' hearts but hopefully all is well now!

We hope you enjoyed your NICU lesson of the day! :)