PPHN

Baby in Incubator

Persistent Pulmonary Hypertension in a Newborn. PPHN is a serious breathing condition in a newborn. You usually don’t need to be a doctor to see it. The baby often turns blue and is struggling to breathe.

The problem is the lung vessels do not open wide enough. This limits blood flow and oxygen and puts the baby at risk.

What is PPHN?

PPHN stands for persistent pulmonary hypertension in the newborn (also called persistent fetal circulation syndrome). PPHN is a rare but very serious circulatory condition in newborn babies that can cause difficulty breathing. PPHN is most common in full-term babies and it occurs in about 1.9 out of every 1,000 births.

PPHN occurs when a baby’s blood vessels do not open properly after birth to allow for normal blood circulation into the lungs which is necessary for the baby to begin breathing independently. During gestation, the baby is supplied with maternal oxygen through the placenta. The lungs are still developing and not in use so vessels that permit blood to circulate to the lungs remain closed. After birth, these blood vessels should open up to immediately allow blood to flow into the lungs so the baby can start using them.

In babies with PPHN, these blood vessels fail to open. This is very dangerous because it means that the baby will be unable to get enough oxygen on its own. Oxygen deprivation can lead to major brain injuries and things like cerebral palsy. PPHN can also be deadly. Even if a diagnosis of PPHN is made within the first 72 hours, the chances of survival are between 10-50%.

Over 50% of newborns with a pneumothorax requiring a chest tube develop PPHN. Sepsis/pneumonia will release inflammatory mediators further inducing vasoconstriction and pulmonary hypertension.

Progress is being made in treating PPHN. A few decades ago, the risk of death was as high as 40%. Today, the mortality rate is 5-10%.

  • Vasa previa is another blood vessel-related problem where the fetal blood vessels lie at the internal opening of the uterus, creating a risk of membrane rupture.
  • Hemoperitoneum is a rare pregnancy complication caused by rupture of venous blood vessels.

Causes / Risk Factors for PPHN

The exact cause of PPHN is not fully understood. However, there are many well-known risk factors that can increase one’s chance of having a child with this “rare” but very concerning condition. PPHN is a disease but it’s almost always secondary to some event. Risk factors for PPHN include:

  • African American ethnicity
  • Term or late pre-term infants > 34 weeks
  • Babies that are too big (macrosomia) to too small (microsomia) for their developmental age at birth
  • Mothers who take certain medications including over-counter NSAIDs such as Aleve, Advil, Ibuprofen or Aspirin for pain relief during pregnancy
    • Tylenol / Acetaminophen is considered a safer alternative for pain relief during pregnancy but always consult with your OB/GYN as guidelines constantly change!
  • Mothers who smoke, vape or ingest/inhale substances containing nicotine during pregnancy
    • Nicotine reduces the functional capacity and ability of fetal pulmonary development by causing vasoconstriction
    • Vasoconstriction of blood vessels reduces both blood flow and oxygen levels of the fetus
  • Cesarean delivered newborns
    • C-section delivered newborns have a statistically higher chance of PPHN when compared to normal vaginal delivery
      • Normal Vaginal Delivery allows for compression of fetal lungs, thus expelling fluid from lungs through the natural birthing process
      • C-Section does not allow for removal of fluid in the lungs
  • Mothers who have an L-Arginine Deficiency, a precursor to Nitric Oxide.
    • Always talk with a nutritionist that is familiar with dietary needs related to pregnancy
  • Unstable or uncontrolled blood pressure while pregnant (Preeclampsia)
    • Careful monitoring of maternal blood pressure is an important part of good prenatal care
    • Healthy blood pressure is normally less than 120/80
  • A low Omega 3/6 diet increases the risk of PPHN
    • Omega 3 and 6 are naturally found in fish. But moms can supplement with over the counter fish oils
    • However, a diet that contains raw fish, oysters, clams, sashimi, and sushi is forbidden during pregnancy as it can cause harm to the developing fetus
  • Certain maternal health conditions including:
    • Gestational diabetes
      • This occurs when the mother’s fasting sugar levels are greater than 126
    • Overweight
      • BMI >25 but <30
    • Obese
      • BMI >30
    • Maternal age over 40
  • Mothers who are currently being treated for any psychological condition where a Selective Serotonin Receptor Inhibitor, better known as an SSRI, has been prescribed
    • Psychological conditions can include but are not limited to:\
      • Depression, Anxiety, Bipolar, Bulimia, Anorexia, Obsessive Compulsive Disorder
        • Consult with your provider if you struggle with any of these
    • SSRI’s include:
      • Prozac (Fluoxetine)
      • Zoloft (Sertraline)
      • Celexa (Citalopram)
      • Lexapro (Escitalopram)
      • Paxil (Paroxetine)
      • If currently taking one of the above medications, please discuss the pros and cons of continuing treatment as PPHN is up to 6x more likely to occur when pregnant and taking an SSRI in the last trimester.
  • Meconium Aspiration
    • 90% of PPHN comes from meconium aspiration.
    • Meconium aspiration occurs in 10-15% of pregnancies. It is usually not a big problem unless it is not diagnosed and treated.
    • Meconium is the newborn’s first bowel movement that can vary in color from green to black
    • Meconium can also mean that a baby is stressed enough that they secrete catecholamines that can increase the GI motility and basically cause them to pass stool in a stressful environment.
    • Post-term babies are at higher risk
    • Aspiration is when a substance is breathed into the lungs that should not be there
      • This can lead to infection and respiratory distress including pneumonia which are life-threatening conditions in a newborn

If your child is at potential risk for PPHN, the NICU staff should act accordingly. When your child is born with PPHN, they may appear to have ‘burned skin’ or dry, flaky appearance that looks like it could be peeled off. Their skin could also have a cyanotic or bluish appearance and struggle to breathe.

A quick diagnosis can be made with an echocardiogram (ultrasound of the heart), measuring oxygen levels and conducting a physical examination. Once PPHN has been confirmed, immediate intervention with some combination of continuous oxygen therapy, CPR, suction of the mouth and orifices, ventilation of the lungs, IV antibiotics and administration of surfactant, a medication that prevents the lungs from sticking together, and Milrinone/Primacor will occur. This medication allows the lungs to properly expand, oxygenate and close placental blood flow. This moment, especially for any parent, can be quite overwhelming. You have to hope that your baby’s care in the right hands and hearts of the professionally trained staff attending to him or her and they know how best to treat your baby.

Oxygen is a solution to PPHN but it is not without risk. Oxygen is a drug and, like any drug, even brief exposure to oxygen when not indicated should be avoided if possible. Still, considering what PPHN can do to a child, it is hard for a doctor to argue that that baby should not be on oxygen if there is any doubt. (We are talking about oxygen without a ventilator.)There is also a lot of controversy now about whether cooling is the standard to care to treat newborns who have PPHN. Many newborns are passively cooled to 33-34 degrees in the 6-hour window prior to total body cooling shortly after birth. Does this help? The studies are all of the map on this.

There are possible long-term complications of PPHN that may not be seen until later in your child’s life. These complications can include hearing deficits, stroke, heart failure, kidney failure, brain hemorrhage, seizures, cerebral palsy, oxygen dependence, and pulmonary disease. These long-term issues can lead to increased chances of both physical and mental disabilities.

PPHN Medical Literature

Throughout this page, we provide hyperlinks to the most recent and/or most important PPHN medical studies. Here are more significant articles in the medical literature that help us better understand PPHN.

  • Humbert M, et al. Pathology and pathobiology of pulmonary hypertension: state of the art and research perspectives. Eur Respir J 2019; 53: 1801887.
  • Wedgwood, S., et. al: Optimal oxygenation and role of free radicals in PPHN. Free Rad Biol Med. 2019; 142: 97–106. This is an interesting article that looks at the supplemental oxygen for infants with PPHN. There is no question that oxygen is a necessary and life-saving therapy for these babies but it is complicated. Supplemental oxygen also has the downside of increased oxidant stress because of the production of free radicals which can cause brain damage.
  • Walsh-Sukys, et. al (2000): Persistent pulmonary hypertension of the newborn in the era before nitric oxide: practice variation and outcomes. Pediatrics. 2000;105:14–20.

Birth Injury