What Is Persistent Pulmonary Hypertension of the Newborn (PPHN)?

Medically Reviewed by Dan Brennan, MD on July 23, 2022
4 min read

Persistent pulmonary hypertension of the newborn (PPHN) is a circulatory condition that occurs soon after birth. It happens to new babies whose lung vessels aren’t open wide enough and have difficulty breathing once they’ve left the womb.

What is persistent pulmonary hypertension of the newborn? In short, PPHN is a serious breathing problem that affects very young babies. It usually affects babies born at full term or at 34 weeks or later. The lungs develop during this part of pregnancy, so it’s common for babies with PPHN to have other breathing conditions too. PPHN is also known as persistent pulmonary hypertension in the newborn and persistent fetal circulation syndrome.

While in the womb, a baby receives oxygen from its mother and the placenta. Blood vessels in the baby’s lungs are almost completely closed, so not much blood actually makes it to the lungs. Those blood vessels will open more after the baby is born and starts to take breaths. Only then will blood be able to travel to the lungs to receive oxygen. When PPHN happens, though, blood vessels in a baby’s lungs don’t open up enough, limiting the amount of oxygen passed along to the baby’s organs and brain.

In addition to the brain and body not receiving the oxygen they need, pressure starts to build in the lungs' blood vessels. This high blood pressure, also known as pulmonary hypertension, is harmful to the baby’s lungs and heart.

Exact PPHN causes aren’t known. It’s possible that underdeveloped or incorrectly developed blood vessels in the lungs cause PPHN. Another possible cause is the blood vessels’ inability to adjust to breathing air once the baby is born.

Although the causes of PPHN aren’t clear, there are definite risk factors that increase the likelihood of developing this condition. These can include:

  • Meconium aspiration, or when a baby inhales its own sticky poop, called meconium
  • Respiratory distress syndrome (RDS), or when a baby is born without completely developed lungs and has difficulty breathing
  • Infections like pneumonia
  • Low oxygen levels before or during the birth process
  • Diaphragmatic hernia, or when there is a hole in the muscle that separates a baby’s chest and abdomen called the diaphragm. A hernia creates an opening for organs that should be in the abdomen push through to the chest
  • Difficult birth experience or birth asphyxia
  • Mothers taking certain medications, like nonsteroidal anti-inflammatory or serotonin receptor inhibitors, during late stages of pregnancy
  • Problems with the heart or lungs 

Symptoms of PPHN can be different in every newborn. Look out for any of the following:

  • Appears to be sick right when they’re born or in the first few hours after birth
  • Quick breathing
  • High heart rate
  • Skin and lips that appear blue
  • Low blood oxygen levels even after receiving 100% oxygen
  • Moaning or grunting when breathing
  • Cold hands and feet
  • Low blood pressure

Health care providers will be quick to diagnose PPHN once a baby is born. In addition to the standard checks done after birth, they may perform the following tests on a baby that might have PPHN:

  • Pulse oximetry, measuring blood oxygen levels in a noninvasive way — the baby’s oxygen levels will be tested at different places in their body and compared to see if blood is making its way to the lungs
  • Blood tests
  • Echocardiogram, taking a detailed ultrasound of the heart and blood vessels
  • Chest X-ray to discover issues with the heart or lungs

When treating PPHN, a health care provider will try to raise blood oxygen levels, regulate blood pressure, and open the blood vessels in the lungs wider. They might try medicine, fluids, or oxygen:

  • Medication and fluids are given to the baby by IV. A tiny, flexible tube is inserted into a few blood vessels to pass along medicine and to take blood samples. It can be placed in the umbilical cord or in an arm or leg. The baby might receive:
    • Antibiotics to prevent or treat infection
    • Medication to maintain healthy blood pressure
    • Surfactant that better enables the baby’s lungs to get rid of carbon dioxide and use oxygen
    • Sedatives that help the baby stay relaxed and well-rested, allowing them to use less oxygen
  • Oxygen can be given to the baby in a number of ways:
    • A continuous positive air pressure (CPAP) machine that gently gets oxygen into the lungs
    • A high-frequency oscillation ventilator that gives quick, short puffs of air via a breathing tube
    • A nasal cannula tube placed in the nostrils and connected to oxygen
    • A ventilator machine that will breathe for the baby until they can do it on their own

Another treatment method is giving the baby nitric oxide. Nitric oxide helps the blood vessels in the baby’s lungs expand.

Once the baby has received initial treatment for PPHN, their lungs could take weeks or months to fully recover. They should be protected from colds, the flu, and other illnesses to avoid making their condition worse. The better they’re able to heal, the less likely it is they’ll have persistent pulmonary hypertension of the newborn long-term effects.

When blood doesn’t make it all the way to a baby’s lungs, they can’t swap oxygen for carbon dioxide. This happens even when receiving 100% oxygen. This is a serious issue because all of the baby’s organs need a steady stream of blood rich in oxygen. If the organs don’t get what they need, serious long-term damage can be done.

Stay in close contact with the baby’s health care provider as they recover from PPHN. Trust your instincts as you care for your child, and reach out if you have serious concerns about your baby’s health.