Persistent Pulmonary Hypertension of the Newborn
Persistent Pulmonary Hypertension in newborns is a serious condition that is characterized by a failure of the circulatory system transition that usually occurs after childbirth. In short, the newborn’s body fails to adapt to life outside of its mother’s womb.
PPHN Causes, Incidence, and Risk Factors
When a fetus exists inside the womb it receives all of its sustenance through the umbilical cord. Nutrients are what most consider, but it also receives oxygen in this manner. Since the lungs of a fetus really do little during its gestation, they require a very small amount of blood. The blood pressure inside an unborn child’s lungs is higher than normal. The extra blood is funneled away from the lungs through a duct known as the ductus arteriosus. However, after the child is born the lungs begin to function and the blood pressure decreases within them while the amount of blood delivered to the lungs increases. The ductus arteriosus closes permanently since it will never again be needed.
But if Persistent Pulmonary Hypertension occurs, the ductus arteriosus remains open and the blood pressure with the newborn’s lungs remains dangerously high. Blood that should be delivered to the lungs is funneled elsewhere in the body. It is very rare, occurring in only about two out of every one thousand newborns.
Although the exact causes of Persistent Pulmonary Hypertension of the newborn is not exactly known, a number of different risk factors have been linked to the condition. These include:
- Conditions affecting the newborn’s mother including anemia, low blood sugar, extreme pneumonia, serious infections, and birth asphyxia.
- Stresses placed on the fetus during its time in the womb. These might be caused by the previously listed conditions or others, such as a child remaining in the womb beyond its due date.
- The use of antidepressants that fall into the class of drugs known as selective serotonin reuptake inhibitors has been linked to PPHN and use of these drugs during pregnancy has been shown to increase the chances of the condition occurring from two in every thousand births to twenty in every one thousand births. These drugs include Prozac, Zoloft, Paxil, Celexa, and their generic counterparts.
There are several signs that can point towards a diagnosis of Persistent Pulmonary Hypertension. While the symptoms may not be as apparent as some birth defects, they can be very serious. Symptoms of PPH include:
- Very rapid heart rate
- Heart murmurs or abnormal heart sounds
- Low levels of oxygen in the blood
- A bluish tint to the skin, known as ‘Cyanosis’
- Rapid breathing
- Other signs of respiratory distress
PPHN Tests and Diagnosis
Diagnosis of Persistent Pulmonary Hypertension of the Newborn will require several different scans or tests. One may not be conclusive, so several different scans may need to be run in order to confirm a diagnosis of PPHN. Below is a list of the various tests doctors may use to determine if a newborn is suffering from this condition.
- Echocardiogram – This heart ultrasound can determine if the heart and other organs have extra blood flowing into them, a sign of PPHN. It will also show signs of heart or lung disease.
- Chest X-Rays – These can help determine if an enlarged heart is present, which is caused by the excess blood not being delivered to the lungs.
- CBC – A complete blood count will uncover the exact amount of white blood cells, platelets, and oxygen in the blood. Low levels of oxygen in the blood can indicate a case of PPHN.
- Arterial Blood Gas – This test is performed to uncover just how effectively oxygen is being transmitted throughout the body.
- Serum Electrolyte Tests – These tests will show the dispersion of vital minerals in the blood of the newborn.
- Pulse Oximetry – Conducting a pulse oximetry test will help doctors determine whether or not the tissues in a newborn’s body are receiving adequate supplies of oxygen by testing the oxygen in the bloodstream.
Since Persistent Pulmonary Hypertension of the Newborn’s most serious threat lies in the lack of oxygen being delivered throughout the body, treatment will normally focus on this aspect as well as increasing blood flow to the lungs. Here are the most common treatments for PPHN.
- Assisted Ventilation – This is the process of a tube being inserted into your child’s lungs to breathe for it.
- Oxygen – Slightly similar and often given along with assisted ventilation, a mask delivering pure oxygen to your baby might be used as well.
- Nitric Oxide – This gas may be administered to the newborn to help relax blood vessels in the lungs, thereby increasing blood flow throughout them.
- Extracorporeal Membrane Oxygenation – This machine functions much like a heart/lung bypass machine and is used during extreme breathing failures. It works by draining blood from the newborn, adding oxygen to it, and then replacing it in the body. Essentially it takes over the functions of both the heart and lungs to give the PPHN time to subside.
The prognosis for Persistent Pulmonary Hypertension of the Newborn will vary depending upon the severity of the condition. In minor cases the issue can be completely reversible and the child could lead a normal life. More serious cases will have a much lower rate of survival due to the damage done to the lungs and heart. While early treatment is vital, sometimes it simply isn’t enough.
PPHN can cause a number of long term effects on a newborn. Those who suffer long term periods of insufficient oxygen can be left with serious, irreparable effects. Some of the most serious complications from PPHN are:
- Heart Failure
- Brain Hemorrhages
- Kidney Failure
- Organ Damage
Long term effects can be just as detrimental and include:
- Chronic seizure disorders
- Brain damage
- Developmental disabilities
- Breathing conditions
- Hearing difficulties
- Newborns may be unable to eat normally for a few weeks after treatment, and a feeding tube may need to be used until their lungs adapt completely.
PPHN Follow Up Care
Due to the stresses that PPHN places on a newborn, your child will likely be monitored very closely for at least two to three years after birth. Hearing tests and other scans will need to be given to ensure that your baby remains in the best health possible.
There are very few preventative steps that expectant mothers can take to help ward off PPHN.
- Stop using selective serotonin reuptake inhibitors as soon as possible.
- Monitor your weight and sugar levels closely.
Keeping these two points in mind during your pregnancy can help to lower the chances that your child will be born with PPHN.
Link PPHN Resources
- Clinical Overview (Newborn Services Guidelines)