OVERVIEW

What is Persistent Fetal Circulation Syndrome?

Persistent Pulmonary Hypertension of the Newborn (PPHN), also known as Persistent Fetal Circulation Syndrome, is related to pulmonary vascular dysplasia. It is a relatively rare neonatal disease, primarily occurring in full-term infants, post-term infants, or preterm infants with a gestational age of 34 weeks or older.

The condition is severe, with a high mortality rate, and surviving infants may experience long-term complications.

After birth, a child's circulatory system undergoes significant changes, transitioning from the "fetal version" to the "adult version." Due to various reasons, if this upgrade fails to occur promptly and the "fetal version" of the circulatory system persists outside the mother's womb, the child will develop a series of abnormalities, the most notable being pulmonary hypertension.

SYMPTOMS

How soon do abnormalities appear in Persistent Fetal Circulation Syndrome? What are the abnormalities?

Some abnormalities may appear prenatally, such as abnormal fetal heart rate or amniotic fluid abnormalities. At birth, the newborn's nails and skin may be stained with meconium. For newborns with prenatal or birth abnormalities, medical staff will provide oxygen therapy, intubation, and other interventions during delivery. Some may be transferred to the neonatal intensive care unit immediately after birth.

Nearly all affected infants will develop symptoms within 24 hours after birth, including rapid breathing and cyanosis (bluish skin and lips).

If the newborn is with the parents, they should monitor the baby's breathing, skin, and lip color closely and promptly inform medical staff if abnormalities are observed.

CAUSES

What causes Persistent Fetal Circulation Syndrome?

Abnormal pulmonary vascular development, intrauterine infection, or maternal use of medications during pregnancy that affect pulmonary vascular development can all prevent timely changes in the fetal circulatory state after birth, leading to persistent pulmonary hypertension in newborns.

Blood circulation differs before and after birth. Before birth, the fetus primarily receives oxygen from the placenta, whereas after birth, oxygen is mainly obtained through the lungs. Prenatally, pulmonary vascular resistance is high, resulting in minimal blood flow to the lungs. Under normal circumstances, after birth, the newborn's pulmonary vessels dilate, increasing blood circulation and triggering a series of changes that transition the circulation from fetal to normal human circulation.

If pulmonary vessels are underdeveloped, malformed, or fail to dilate promptly due to infection or other factors, the circulatory transition cannot occur in time. This leads to insufficient oxygen supply in the newborn, causing a range of symptoms.

DIAGNOSIS

What tests are needed for Persistent Fetal Circulation Syndrome?

Echocardiography is the primary test used to observe whether the newborn's heart structure is normal and to assess pulmonary artery morphology and pressure abnormalities.

In addition, newborns generally require chest X-rays, electrocardiograms, blood tests, and other examinations.

TREATMENT

How to treat persistent fetal circulation syndrome? How long does the treatment take?

Persistent pulmonary hypertension of the newborn (PPHN) requires treatment in the neonatal intensive care unit (NICU). The duration of treatment varies from one week to several months depending on the severity of the condition. Parents should cooperate fully with medical staff.

Possible treatments include:

• Oxygen support: Most infants require ventilator-assisted breathing.
• Vasoactive drugs: Improve circulation and reduce pulmonary artery pressure.
• Extracorporeal membrane oxygenation (ECMO): Acts as an artificial lung, performing gas exchange externally to maintain oxygen supply, significantly improving survival rates.

Additionally, treatments such as fluid replacement, acidosis correction, and infection control may be administered.

Is treatment effective for persistent fetal circulation syndrome?

The effectiveness of treatment depends on the underlying cause. If the condition is due to underdeveloped pulmonary vasculature, the child may also have other developmental abnormalities, leading to poorer treatment outcomes and higher mortality rates.

If the condition results from abnormally thickened pulmonary vascular walls or maladaptation of pulmonary vessels, timely treatment can yield relatively better outcomes. The application of ECMO technology has significantly improved survival rates and quality of life post-treatment.

What long-term effects might a child have after treatment for persistent fetal circulation syndrome?

Possible long-term effects include growth retardation, abnormal motor development, and hearing impairment. These risks are higher in severe cases, but most surviving children can grow and live like their peers.

Children diagnosed with PPHN should undergo developmental assessments every six months after birth to monitor for abnormalities. Early rehabilitation can help intellectual development approach normal levels.

For severe cases or those treated with ECMO or iNO, neurodevelopmental assessments should be conducted every 6–12 months for the first two years, along with hearing tests before discharge and at 18–24 months of corrected age.

DIET & LIFESTYLE

Does persistent fetal circulation syndrome occur in the first child and will it also appear in the second child?

There is currently no evidence to suggest that neonatal persistent pulmonary hypertension is related to parental genes. Therefore, there is generally no need to worry about the condition recurring in subsequent pregnancies.

PREVENTION

How to Prevent Persistent Fetal Circulation Syndrome?

Some studies suggest that maternal use of nonsteroidal anti-inflammatory drugs (NSAIDs) or selective serotonin reuptake inhibitors (SSRIs) during pregnancy may increase the risk of persistent pulmonary hypertension in newborns. Avoiding these medications during pregnancy and monitoring fetal movement and heart rate may help prevent the occurrence of persistent pulmonary hypertension in newborns.