What Happens to Extremely Preterm Infants in Adulthood?
Insights from the HAPI Study
What is the long-term health of adults born before 29 weeks?
The HAPI study examines cardiovascular and kidney outcomes in young adults born extremely preterm.
We Often Ask Ourselves…
In neonatal intensive care, we care for babies born at 24, 25, or 26 weeks of gestation.
But what happens 20 or 25 years later?
These are precisely the questions addressed by the HAPI study (Health of Adults born Preterm Investigation).
The HAPI Study: Following Preterm Infants into Adulthood
The HAPI study, led by Dr. Anne-Monique Nuyt and Dr. Thuy Mai Luu at CHU Sainte-Justine and funded by the Canadian Institutes of Health Research, examines the long-term health of individuals born before 29 weeks of gestation.
Who participated?
- Approximately 100 young adults born extremely preterm
- Mean age: 23 years
- Born between 1987 and 1994
- Compared with a control group of age-matched adults born at term
This comprehensive observational study evaluated:
One key component, led by Dr. Kathryn Paquette during her fellowship, focused specifically on kidney health and blood pressure. These findings were published in Hypertension.
Kidney Size: Smaller, But Functional
One of the central findings was anatomical.
Young adults born extremely preterm had significantly smaller kidneys on ultrasound compared with adults born at term.
This finding is biologically plausible. Nephron development (the formation of the kidney’s functional units) continues until approximately 34–36 weeks of gestation. Birth before 29 weeks interrupts this developmental process.
The reassuring news:
Despite smaller kidney size, measured kidney function was normal.
There was no evidence of kidney failure or reduced filtration capacity at this age.
Blood Pressure: Subtle Differences
The study also found that:
- Average blood pressure was modestly higher in adults born extremely preterm compared with term-born controls.
- Smaller kidney size was associated with higher blood pressure within the preterm group.
Importantly, this does not indicate severe hypertension.
Rather, it suggests a subtle cardiovascular profile difference that may warrant awareness over time.
What Do These Findings Mean?
The HAPI study presents a nuanced picture:
Prematurity does not predetermine poor health.
However, it may leave subtle biological imprints.
HAPI Fit: Moving from Observation to Prevention
HAPI Fit project builds on these findings.
Unlike HAPI, which is observational, HAPI Fit is interventional. It evaluates whether a 14-week supervised exercise program can improve:
- Cardiovascular function
- Vascular health
- Lung capacity
- Muscle strength
- Metabolic parameters
in young adults born extremely preterm.
This shift is important.
Rather than simply identifying differences, researchers are exploring strategies to optimize long-term health.
A Message of Reassurance
and Responsibility
The babies cared for in NICUs grow into adults.
The HAPI findings suggest:
- Most are doing well.
- Some may benefit from cardiovascular monitoring.
- Healthy lifestyle habits, including regular physical activity, are particularly important.
These results should not cause alarm. They highlight the importance of informed, preventive care.
Conclusion
Adults born extremely preterm demonstrate overall good health in early adulthood.
At the same time, subtle cardiovascular and anatomical differences remind us that prematurity is a lifelong biological starting point.
The goal is not concern, but awareness. And perhaps most importantly:
the survival of extremely preterm infants now extends well into healthy adulthood.
Learn more : https://pubmed.ncbi.nlm.nih.gov/30103050/