Stem Cell Treatment Could Help Newborns With Brain Damage

A recent study conducted at UMC Utrecht, Netherlands, has shown that mesenchymal stem cells (MSCs) are a safe treatment for brain damage caused by stroke in newborns, and could have a significant positive effect.

Perinatal stroke and its consequences

Perinatal stroke is defined as a stroke that happens to unborn or newborn babies before, during, or shortly after birth, typically between the last few months of pregnancy and one month of age.[1] It is estimated to affect about 1 in 1000 to 3000 children at birth[1][2], although the real figure may be higher as it is likely underdiagnosed.[2]

Perinatal stroke, particularly perinatal arterial ischemic stroke (PAIS) which is the most common type (70% of cases)[2], can have serious consequences. Depending on the artery involved, 50-70% of children who suffered a perinatal stroke will have lifelong issues, including cerebral palsy, epilepsy, vision issues, cognitive impairment and language delays.[3] There is currently no treatment available that can alleviate these issues; the current standard of care is limited to supportive measures.[2][3] Thus, there is an urgent need to develop an effective regenerative treatment and ensure children who suffered a stroke get the best possible start in life.

The PASSIoN study

A research team at UMC Utrecht has been focusing on developing a treatment for perinatal stroke using MSCs.[3] These powerful stem cells offer several advantages, boasting neuroregenerative and anti-inflammatory properties that could prove key to reducing the impact of stroke on a newborn’s brain.[4] Administration of the MSCs via nose drops was selected as being the method of treatment that could potentially deliver the most stem cells to the brain.[3][4]

Following on from preclinical studies in mice, researchers set up a phase 1 clinical trial, called PASSIoN (Perinatal Arterial Stroke treated with Stromal cells IntraNasally), to determine the safety of the treatment.

Newborns were eligible for inclusion into the trial if they were born at any of the neonatal intensive care units in the Netherlands and showed symptoms of PAIS, including seizures and breathing difficulties. Eligible newborns were transferred to UMC Utrecht, where an MRI was performed to confirm whether they had a stroke; if so, they received the stem cell treatment within 7 days after first showing symptoms. In total, ten newborns received the treatment between February 2020 and April 2021.[3]

What were the results?

Initial results for the study were published in 2022, in the prestigious The Lancet journal. The treatment proved to be safe, with no serious adverse events found either immediately after treatment or at the three-month follow-up visit. One newborn did develop a high fever after treatment, but it passed spontaneously within a few hours. Moreover, an MRI scan done at the three-month follow-up showed no unexpected brain abnormalities.

More recently, researchers published long-term follow-up results for the study, along with a comparison between the study patients and a cohort of newborns with stroke who received standard of care treatment. This comparison cohort was selected from the Neonatal Stroke Registry Utrecht using criteria that would have resulted in their enrollment in the PASSIoN trial had it been running at the time of their birth.[5][6]

Two years after treatment, the children continue to experience no side effects; although there were two hospital admissions among the study group, these were found to have been unrelated to the treatment. Most children developed well from a cognitive point of view, with one showing a mild cognitive delay, two having language delays, and one suffering from severe sleep problems. MRI scans showed that the amount of brain tissue loss was less than would have been expected given the severity of the strokes.

In terms of motor development, too, the children who received the treatment performed better than the comparison group. All children in the study initially showed damage to the areas of the brain that control movement. This is something which usually carries a risk of developing cerebral palsy higher than 80%. However, only two children (20%) in the study group developed mild CP. In the comparison group, the rate of CP was 50%, and scientific literature reports rates of up to 70%.

A long-awaited paradigm shift

Pediatrician and professor Manon Benders from UMC Utrecht, who co-led the PASSIoN study, says that seeing this kind of positive development in such a high-risk group is truly extraordinary.[6]

Following the success of this safety study, a larger trial, called iSTOP-CP, is now due to begin in early 2026. This trial will include a total of 162 newborns with brain damage due to either perinatal stroke or severe oxygen deprivation. Researchers will administer either the stem cell treatment or a placebo within 7 days of birth, then monitor their development up to the age of 24 months. It is hoped that the larger study will confirm the treatment’s effectiveness, bringing about a long-awaited paradigm shift in the treatment of neonatal brain damage.[6][7]

Clinical trials and studies like this make it clear that stem cells could hold the key to treating many illnesses and conditions that currently have no cure. Indeed, a recent review article has statistically confirmed that infusions of cord blood, which is rich in young, potent stem cells, can be an effective treatment to improve motor skills in children with CP. In the case of neonatal brain damage, too, it could be possible to develop a treatment using the baby’s own stem cells, collected from the cord blood.[4]

This would only be feasible, however, if the cord blood is collected and stored after birth. Unfortunately, this often doesn’t happen, as the umbilical cord and placenta are routinely discarded as medical waste following the birth. To learn how you could preserve this unique source of stem cells for your baby’s future use, should they ever need it, simply request your free info kit below.

References

[1] American Stroke Association. Perinatal Stroke Infographic. https://www.stroke.org/en/about-stroke/stroke-in-children/perinatal-stroke-infographic

[2] Whitaker, E.E.; Cipolla, M.J. Chapter 16 – Perinatal Stroke. In Handbook of Clinical Neurology; Steegers, E.A.P., Cipolla, M.J., Miller, E.C., Eds.; Neurology and Pregnancy; Elsevier: Amsterdam, The Netherlands, 2020; Volume 171, pp. 313–326.

[3] Baak, L.M., et al. (2022). Feasibility and safety of intranasally administered mesenchymal stromal cells after perinatal arterial ischaemic stroke in the Netherlands (PASSIoN): a first-in-human, open-label intervention study. The Lancet Neurology, 21(6), pp.528–536. doi:https://doi.org/10.1016/s1474-4422(22)00117-x

[4] Wagenaar, N., Nijboer, C.H. and Bel, F. (2017). Repair of neonatal brain injury: bringing stem cell‐based therapy into clinical practice. Developmental Medicine & Child Neurology, 59(10), pp.997–1003. doi:https://doi.org/10.1111/dmcn.13528

[5] Wagenaar, N., et al. (2025). PASSIoN Trial (Perinatal Arterial Stroke Treated With Intranasal Stromal Cells): 2-Year Safety and Neurodevelopment. Stroke. doi:https://doi.org/10.1161/strokeaha.125.050786

[6] Research at UMC Utrecht. (2025). Stem cell treatment offers hope for newborns with brain damage. https://research.umcutrecht.nl/news/stem-cell-treatment-offers-hope-for-newborns-with-brain-damage/

[7] Christensen, R. and Moharir, M. (2025). Mesenchymal Stromal Cells: A New Hope for Perinatal Arterial Ischemic Stroke. Stroke, 56(9), pp.2419–2421. doi:https://doi.org/10.1161/strokeaha.125.052219