For decades, the diagnosis of spina bifida during pregnancy carried a weight that few other words could match. Parents faced impossible choices, uncertain outcomes, and the knowledge that their child would likely face a lifetime of challenges. But a breakthrough published this month in The Lancet may have just rewritten that story.

A research team at UC Davis Health has completed Phase 1 of a clinical trial demonstrating that the world's first spina bifida treatment combining fetal surgery with stem cells is safe — a result that opens the door to what could become a transformative approach to one of the most common birth defects in the world.

## What Is Spina Bifida?

Spina bifida occurs when the neural tube — the structure that becomes the brain and spinal cord — doesn't close completely during early development. This leaves the spinal cord and nerves exposed, which can lead to paralysis, bladder and bowel problems, and hydrocephalus, a dangerous buildup of fluid in the brain.

Approximately 1,500 babies are born with spina bifida each year in the United States alone. Current treatments include fetal surgery to close the opening before birth, which has been shown to improve outcomes compared to postnatal repair. But even with surgery, many children still face significant disabilities.

## The Stem Cell Innovation

The UC Davis team, led by Professor Aijun Wang and a multidisciplinary group of surgeons and biomedical engineers, took the existing fetal surgery approach and added something new: human placental mesenchymal stromal cells. These stem cells, derived from placental tissue, were applied directly to the exposed spinal cord during the in-utero repair procedure.

The hypothesis was elegant: the stem cells could promote healing, reduce inflammation, and potentially help regenerate damaged nerve tissue in ways that surgery alone cannot achieve.

"We're not just closing a wound anymore," explained Dr. Wang in a university statement. "We're giving the body biological tools to heal itself at a cellular level, at the earliest possible moment."

## The Results

The Phase 1 trial focused primarily on safety, and the results were unambiguously positive. The combination therapy was performed successfully on multiple patients, with no adverse effects attributed to the stem cell component. Both mothers and babies tolerated the procedure well.

While the trial was designed to evaluate safety rather than efficacy, early observations are encouraging. The research team noted promising signs of improved neural function in treated patients compared to historical outcomes, though they cautioned that larger studies are needed to confirm these preliminary findings.

## What This Means for Families

For the families who participated in the trial, the results are deeply personal. One mother, who asked to remain anonymous, described the experience of learning about the trial during what she called "the darkest week of my life."

"When they told us about the diagnosis, everything stopped," she said. "But when they told us about this trial — that they could not only operate but also give our baby stem cells to help heal — it was the first time I felt hope."

Her child, now a toddler, is meeting developmental milestones that doctors initially said would be unlikely.

## The Road Ahead

The team is now moving into Phase 2 of the trial, which will enroll more patients and begin to rigorously measure efficacy outcomes. If the results hold, this approach could fundamentally change the standard of care for spina bifida worldwide.

Dr. Diana Farmer, a pioneer of fetal surgery at UC Davis, called the results "a new chapter in fetal medicine. We've shown that combining surgery with regenerative biology is not only possible but safe. Now we find out just how much good it can do."

For the approximately 300,000 babies born with neural tube defects globally each year, that next chapter can't come soon enough.