The first hours of a tough start
A full-term baby takes her first breath. But her lungs don't open the way they should. Blood keeps flowing the way it did in the womb, skipping the lungs. Oxygen levels drop.
This is persistent pulmonary hypertension of the newborn (PPHN — when blood vessels in a newborn's lungs stay too tight after birth).
It is scary. It is serious. And it puts huge strain on the baby's heart.
A new trial asks whether a familiar hormone — melatonin — might help.
PPHN affects about 2 out of every 1,000 live births. Many of these babies end up in a NICU, often on a ventilator.
Standard treatments include oxygen, nitric oxide gas to relax lung vessels, and sometimes heart support drugs. These help. But the heart still works overtime.
The left ventricle — the chamber that pumps blood to the whole body — takes a beating. When it weakens, everything from the brain to the kidneys feels the drop.
Doctors have been searching for add-on treatments that protect the heart while the lungs heal.
The old way versus the new way
Melatonin is best known as the sleep hormone. Your body makes it in the evening to help you rest.
But in labs, researchers have found something else. Melatonin is a powerful antioxidant (a molecule that mops up cell-damaging chemicals called free radicals).
In PPHN, low oxygen triggers a flood of those damaging molecules. They injure heart muscle cells.
Here's the twist. If melatonin could quiet that storm, the heart might recover faster. That is the idea this trial tested.
Think of a house with a smoldering fire. Standard PPHN care is the fire department — cooling things down with oxygen and medicine.
Melatonin is more like a sprinkler system built into the walls. It does not put out the fire alone. But it soaks the structure before it catches, limiting damage.
For a newborn heart working twice as hard as normal, that early protection could mean a faster, fuller recovery.
Researchers enrolled 80 newborns at 36 weeks or older with confirmed PPHN. All were in the NICU and needed intensive care.
Half got standard therapy alone. Half got standard therapy plus oral melatonin. Doctors measured heart function with echocardiograms (ultrasound of the heart). They also tracked blood markers of stress and inflammation.
The trial was registered on ClinicalTrials.gov and used randomized placebo-style assignment.
The melatonin group had better heart function. Standard echo numbers and more advanced measures both showed the left ventricle was pumping better.
The differences were not subtle.
Babies on melatonin came off ventilators earlier. They needed less respiratory support. And they went home from the hospital sooner.
This is what parents and doctors want to hear — better hearts, shorter machines, shorter stays.
Blood tests told the same story. Two warning markers — HMGB1 (a sign of cell damage) and NT-proBNP (a sign of heart strain) — were lower in the melatonin group.
The surprising shift
For years, PPHN treatment has focused on the lungs. Open the vessels. Get oxygen moving.
This study turns some of that attention back to the heart. A lung-first approach saves lives, but it may leave the heart underprotected.
Melatonin offers something different. It is cheap. It is well studied in adults. It has a long safety record. And it acts on the damage pathway — oxidative stress — that all PPHN babies share.
That combination makes it attractive for a careful test.
The authors say melatonin should be viewed as an add-on, not a replacement. Standard PPHN care saves lives and will stay in place.
They believe melatonin's antioxidant and mild vessel-relaxing effects may ease the heart's load while the lungs recover. Their trial is one of the first randomized tests in human newborns with PPHN.
Similar work in adults with heart strain has shown modest benefits. Seeing a larger signal in newborns is consistent with the idea that very young tissue responds strongly to antioxidant protection.
If your baby is in a NICU with PPHN, this trial does not change tonight's care. Melatonin is not yet a standard part of PPHN treatment guidelines.
But it is reasonable to ask the care team if they are following the research. Some NICUs may start using melatonin cautiously based on studies like this. Others will wait for larger trials.
Parents should know this: the standard treatments available today are strong. This is about making good care even better, not replacing what works.
Limitations to keep in mind
Eighty babies is a meaningful number, but it is still a single trial at likely one or a few centers. Results in one NICU may not repeat everywhere.
The babies were at least 36 weeks gestational age. Premature babies were not studied, so the findings do not apply to them.
Longer-term outcomes — brain development, lung health, and growth at age 1 or 2 — were not reported here. Those are the outcomes that matter most for families.
Larger multi-center trials are the next step. Researchers want to confirm the heart and lung benefits in hundreds of babies across different countries and hospitals.
They also want to fine-tune the dose and timing. When should melatonin start? How long should it continue? Oral, intravenous, or both? These questions matter for real-world use.
If the findings hold up, melatonin could become an inexpensive, widely available add-on to PPHN care. That is a meaningful goal — especially for hospitals without access to the newest, costliest therapies.
For now, this trial is a careful, hopeful step. A hormone most people know only as a sleep aid may one day help the smallest hearts heal a little faster.