Pulmonary Hypertension in Newborns and Premature Babies: PPHN, BPD, and What Parents Should Know

Key takeaways

• In some babies, high lung pressure comes from the lungs or the birth transition, not a heart defect.
• PPHN is a short-term form. It appears within hours of birth, when the lung circulation fails to switch over, and is treated in a neonatal unit.
• Not all newborn pulmonary hypertension is PPHN. Underdeveloped lungs, as in a diaphragmatic hernia, can also raise lung pressure.
• Premature babies with chronic lung disease, called bronchopulmonary dysplasia (BPD), can develop it over weeks rather than hours.
• India has the highest number of preterm births in the world, so BPD-related lung pressure matters here.
• An echocardiogram is the first test, and early specialist review gives the best chance of a good result.

Few things rattle new parents more than a baby who struggles to breathe. In some newborns, the trouble lies in the lungs: the arteries that carry blood through them stay under high pressure, so the baby cannot take in enough oxygen. Doctors call this pulmonary hypertension.

In babies, it often has nothing to do with a heart defect. It can begin with the way the body changes at birth, or with lungs that are still growing, especially in babies born early. This guide explains pulmonary hypertension in newborns and premature babies in plain terms: the forms it takes, the signs, how it is diagnosed, and how it is treated.

What is pulmonary hypertension in newborns and premature babies?

Pulmonary hypertension in newborns is high pressure in the arteries that carry blood to the lungs, caused by the lungs or the birth transition rather than a heart defect. It takes three main forms: PPHN in the first hours of life, pulmonary hypertension from underdeveloped lungs, and the longer-term pressure that can build in premature babies with chronic lung disease.

Before birth, a baby’s lung arteries are tight and blood bypasses the lungs. At birth they should relax and open. Neonatal pulmonary hypertension happens when this does not go to plan, or when the lungs have not formed properly. For the wider picture, see our guide to pulmonary hypertension treatment.

PPHN: when the lungs do not switch over at birth

Persistent pulmonary hypertension of the newborn (PPHN) happens when a baby’s lung arteries stay tight after birth, so blood cannot pick up enough oxygen. It usually shows within hours of birth, in babies born at or near term, and is treated as an emergency in a neonatal unit.

The most common trigger is meconium aspiration, when a baby breathes in the first stool around the time of birth. Infection such as sepsis or pneumonia, breathing distress, and a difficult birth with low oxygen are other frequent causes (Merck Manual, PPHN).

The main PPHN symptoms are fast breathing, grunting, and a deep blue colour that barely improves with oxygen. Care is given in a neonatal intensive care unit, and may include oxygen, breathing support, a gas called inhaled nitric oxide that relaxes the lung arteries, and medicines to support the heart. In severe cases, a heart-lung bypass machine (ECMO) is used. Many babies recover well with timely care.

Neonatal pulmonary hypertension beyond PPHN

Not all pulmonary hypertension in newborns is the short-term PPHN type. Some babies have high lung pressure because their lungs or lung vessels did not form fully before birth. This form tends to last longer and needs a clear diagnosis of the cause.

A key example is a congenital diaphragmatic hernia, where a gap in the muscle below the lungs lets other organs press into the chest. The lungs and their vessels stay small, and lung pressure runs high. In a study from AIIMS, New Delhi, pulmonary hypertension was found in about half (51%) of newborns with a diaphragmatic hernia, and it was a major reason some did not survive. Other causes include underdeveloped lungs from low fluid around the baby in pregnancy. These babies need a specialist to pin down the cause, because treatment and outlook differ from simple PPHN.

Bronchopulmonary dysplasia (BPD) and pulmonary hypertension in premature babies

Bronchopulmonary dysplasia is a chronic lung disease of premature babies. Their lungs are still developing and often need oxygen or breathing support for weeks. Over time, this strain on the lung vessels can lead to pulmonary hypertension, which builds slowly rather than appearing at birth.

This matters more in India than many parents realise. India records about 3 million preterm births each year, the highest number of any country and more than a fifth of the world total, according to the WHO and UNICEF. More premature babies surviving is good news, but it also means more at risk of BPD and its complications.

The risk of pulmonary hypertension rises with how severe the lung disease is. One large review found high lung pressure in about 5% of babies with mild BPD, 18% with moderate BPD, and 41% with severe BPD (BPD-PH meta-analysis). Because the pressure creeps up quietly, specialists often screen premature babies with moderate or severe BPD using a heart scan, so it can be caught early.

How it is diagnosed in babies

Diagnosis starts with an echocardiogram, a painless scan that estimates lung pressure and checks the heart. In selected babies, a specialist may advise a cardiac catheter test to measure the pressure directly.

The echocardiogram is safe even for tiny premature babies, and it also rules out a heart defect. In premature babies with significant BPD, it is often repeated over time, because pulmonary hypertension can develop later.

How pulmonary hypertension in newborns is treated

Treatment has two parts: supporting the baby’s breathing and oxygen, and treating the cause. The approach depends on which form the baby has, so care is always planned by a specialist team.

For premature babies with BPD, treating the lung disease itself is central: careful oxygen use, good nutrition for growth, and long follow-up. Medicines to lower lung pressure may be added when a specialist advises.

The outlook

The outlook depends on the cause and how early it is treated. Many babies with PPHN recover fully. Babies with BPD or underdeveloped lungs need longer care, but many still do well with the right support.

PPHN often settles once the baby is over the first difficult days. Pulmonary hypertension linked to BPD or lung problems takes longer and needs close follow-up as the child grows. Across all forms, catching it early and treating the cause gives the best chance of a good result.

Getting your baby the right care early

Pulmonary hypertension in newborns and premature babies is easy to miss, because it hides behind breathing trouble that already worries every parent in a neonatal unit. Yet early diagnosis and specialist care change the outlook.

Dr Prashant Bobhate is a paediatric cardiologist who focuses on pulmonary hypertension in children, from newborns with PPHN to premature babies with BPD. He offers full assessment, including echocardiography and cardiac catheterisation, and plans treatment around each baby’s cause and stage. If your newborn or premature baby has been told they have high lung pressure, book a consultation for a clear, expert opinion.

References

1. Persistent Pulmonary Hypertension of the Newborn (PPHN). MSD/Merck Manual, Professional. https://www.merckmanuals.com/professional/pediatrics/respiratory-problems-in-neonates/persistent-pulmonary-hypertension-of-the-newborn-pphn
2. Mascarenhas D, et al. Pulmonary hypertension in preterm neonates with bronchopulmonary dysplasia: a meta-analysis. Archives of Disease in Childhood: Fetal and Neonatal Edition, 2025. https://fn.bmj.com/content/110/4/344
3. Sahoo T, et al. Clinical profile and predictors of mortality in neonates with congenital diaphragmatic hernia. Indian Pediatrics, 2019. https://www.indianpediatrics.net/dec2019/dec-1037-1040.htm
4. Born Too Soon: Decade of Action on Preterm Birth. WHO, UNICEF and PMNCH, 2023.