When babies are born early or have trouble breathing, doctors sometimes give them extra oxygen. Scientists wondered if this extra oxygen could cause high blood pressure problems later in life, especially for babies born to mothers who were overweight. Researchers studied rats from both lean and obese mothers, giving some newborns extra oxygen for a week and others normal air. Surprisingly, the babies who received extra oxygen actually had lower blood pressure as young adults compared to those who didn’t. This good news suggests that giving newborns oxygen therapy doesn’t increase their risk of developing high blood pressure, even when their mothers were overweight.

The Quick Take

  • What they studied: Whether giving newborns extra oxygen in their first week of life causes high blood pressure problems when they grow up, and whether this risk is worse for babies born to overweight mothers.
  • Who participated: Male and female newborn rats from 12-18 mothers in each group. Half the mothers were lean and healthy, and half were obese. The baby rats were followed from birth until they were 12 weeks old (roughly equivalent to young adulthood in humans).
  • Key finding: Newborns exposed to extra oxygen actually had lower blood pressure as young adults (about 6 points lower in males, 6 points lower in females) compared to newborns who breathed normal air. This was true for babies from both lean and obese mothers.
  • What it means for you: If you have a premature baby or a newborn who needs oxygen therapy, this research suggests that treatment is unlikely to cause high blood pressure problems later in childhood or adulthood. However, this is animal research, so results may differ in human babies. Always follow your doctor’s recommendations for oxygen therapy.

The Research Details

Scientists used laboratory rats to study how extra oxygen affects blood pressure development. They divided newborn rats into groups based on whether their mothers were lean or obese. Then they exposed some newborns to high oxygen (80% oxygen, similar to what premature babies receive in hospitals) for one week starting at day 3 of life, while other newborns breathed normal air (21% oxygen). After returning all babies to normal air, the researchers waited until the rats were 12 weeks old—roughly equivalent to young adults—and then measured their blood pressure and heart rate using special monitoring devices placed inside their bodies.

The researchers also measured how well the heart was pumping by looking at how quickly the heart muscle contracted. They compared all the different groups: lean mothers with normal oxygen, lean mothers with extra oxygen, obese mothers with normal oxygen, and obese mothers with extra oxygen.

This approach allowed the scientists to test two important questions: Does extra oxygen alone cause high blood pressure? And does extra oxygen make the blood pressure problems from maternal obesity even worse?

This research design is important because it separates the effects of extra oxygen from the effects of maternal obesity. By studying both factors together, scientists can understand whether oxygen therapy adds extra risk on top of the risk already created by maternal obesity. This helps doctors know whether they need to worry about long-term blood pressure problems when treating premature or struggling newborns.

This is an animal study using rats, which means results may not directly apply to human babies. The sample size is relatively small (12-18 mothers per group), which is typical for laboratory animal research but means results should be confirmed in larger studies. The study was well-designed with clear groups and careful measurements of blood pressure using reliable technology. However, because this is one study in rats, the findings need to be confirmed in human populations before changing medical practice.

What the Results Show

The main surprise was that newborns exposed to extra oxygen had lower blood pressure as young adults, not higher. In male rats from lean mothers, those exposed to extra oxygen had blood pressure of 105 mmHg compared to 111 mmHg in controls—a difference of 6 points. Female rats showed a similar pattern with 102 mmHg versus 108 mmHg. This was unexpected because scientists thought extra oxygen might damage the developing blood vessels and heart.

For babies from obese mothers, the pattern was even more interesting. Male offspring from obese mothers who received extra oxygen had blood pressure of 117 mmHg compared to 123 mmHg in those who didn’t—again, lower in the oxygen-exposed group. Female offspring showed 113 mmHg versus 116 mmHg. Heart rate also decreased in the oxygen-exposed groups from obese mothers.

When researchers looked at how well the heart was pumping, they found that extra oxygen actually improved heart function in offspring from obese mothers. In offspring from lean mothers, extra oxygen slightly reduced one measure of heart pumping strength, but this didn’t translate to higher blood pressure.

These results suggest that brief exposure to extra oxygen early in life doesn’t harm blood pressure development and may even have some protective effects, particularly in offspring at risk from maternal obesity.

The heart rate findings are noteworthy. Offspring from obese mothers who received extra oxygen had lower heart rates (351 bpm in males, 376 bpm in females) compared to those who didn’t receive oxygen (358 bpm and 390 bpm respectively). Lower resting heart rate is generally considered a sign of better cardiovascular health. The improvement in heart pumping function in oxygen-exposed offspring from obese mothers suggests that extra oxygen may actually help the developing heart adapt better, at least in this animal model.

Previous research had raised concerns that extra oxygen exposure in newborns might damage developing blood vessels and increase blood pressure later. This study contradicts that concern, at least for the specific oxygen exposure pattern tested (high oxygen for one week in early life). The findings align with some recent research suggesting that brief, controlled oxygen exposure may not be as harmful as once feared, though other studies have shown problems with prolonged or uncontrolled oxygen exposure. The protective effect in offspring from obese mothers is particularly novel and suggests that the developing cardiovascular system may respond differently to oxygen stress depending on the starting conditions.

The biggest limitation is that this is rat research, not human research. Rats’ bodies develop differently than human bodies, and they have different lifespans and metabolism. Results at 12 weeks in rats may not translate to human children or adults. The study only followed animals until young adulthood; longer-term effects into older age weren’t measured. The oxygen exposure was brief (one week) and occurred at a specific time in development; different timing or duration might produce different results. The study didn’t examine all possible measures of heart and blood vessel health. Additionally, the sample size, while appropriate for animal research, is relatively small, so results should be confirmed in larger studies before drawing firm conclusions.

The Bottom Line

Based on this research, there is no evidence that short-term oxygen therapy in newborns causes high blood pressure in childhood or early adulthood. In fact, this study suggests it may not increase blood pressure risk even in babies born to overweight mothers. However, this is animal research, and human studies are needed to confirm these findings. Doctors should continue to use oxygen therapy when medically necessary for newborns without concern about this particular long-term risk, but should still monitor overall cardiovascular health as part of routine care. Confidence level: Moderate for animal model; results need human confirmation.

Parents of premature babies or newborns who received oxygen therapy should find this reassuring—it suggests their child’s oxygen treatment is unlikely to cause high blood pressure problems later. Doctors caring for newborns can use this information to feel more confident about prescribing necessary oxygen therapy. Researchers studying long-term effects of neonatal care should note these findings. People with family history of high blood pressure should not assume their risk is increased if they received oxygen as a newborn. However, this doesn’t mean oxygen therapy has no risks—it only addresses blood pressure specifically.

In this animal study, blood pressure differences were measurable at 12 weeks of age (equivalent to young adulthood in rats). In human children, similar effects might not be apparent until late childhood or early adulthood. If you’re concerned about a child’s blood pressure after neonatal oxygen therapy, routine blood pressure checks during regular doctor visits are appropriate, but there’s no evidence of increased risk based on this research.

Want to Apply This Research?

  • For parents of children who received neonatal oxygen therapy, track blood pressure readings at annual check-ups (if available through your healthcare provider) and note any family history of high blood pressure. Record the child’s age at oxygen exposure and duration to share with healthcare providers.
  • Use the app to set reminders for regular blood pressure checks during routine doctor visits. Log lifestyle factors known to affect blood pressure (physical activity, salt intake, stress) to maintain overall cardiovascular health. Set goals for healthy habits that support good blood pressure regardless of neonatal history.
  • Create a long-term health profile that includes neonatal oxygen exposure history. Set annual reminders to discuss cardiovascular health at doctor visits. Track any blood pressure readings over time to identify trends. Monitor family history of hypertension separately to understand total risk factors.

This research is based on animal studies in rats and has not been confirmed in human newborns. While the findings are encouraging, they should not replace medical advice from your pediatrician. If your child received oxygen therapy as a newborn, continue routine health check-ups and blood pressure monitoring as recommended by your doctor. This information is for educational purposes and should not be used to make decisions about medical treatment without consulting your healthcare provider. Always follow your doctor’s recommendations regarding oxygen therapy and cardiovascular monitoring for your child.