For decades, the best available treatment for spina bifida was surgery — open the womb, close the spine, and hope for the best. In skilled hands, that surgery improved outcomes. But many children still faced significant paralysis, requiring lifelong mobility aids, and dealing with bladder and bowel complications that can dominate daily life.
Now a team at UC Davis Health has gone a step further. And their early results, published in *The Lancet* in February 2026, are the kind that make scientists catch their breath.
The CuRe Trial — Cellular Therapy for In Utero Repair of Myelomeningocele — is the world's first clinical trial of stem cell therapy for spina bifida in the womb. The approach goes beyond closing the spinal opening: surgeons apply a special gel or patch containing placenta-derived mesenchymal stem cells (PMSCs) directly onto the exposed spinal cord of the fetus during the standard surgical repair. These stem cells, taken from the mother's placenta, are known to reduce inflammation, promote healing, and protect nerve tissue.
Phase 1 of the trial enrolled six pregnant women whose fetuses had been diagnosed with myelomeningocele — the most severe form of spina bifida — between July 2021 and December 2022. The primary question was safety: could this treatment be given without causing harm?
The answer, across every case, was yes.
All six babies had their spinal repairs intact. No infections. No abnormal tissue growth. No tumour formation. None required a shunt for hydrocephalus before leaving hospital — a common complication that often follows spina bifida surgery.
But the result that has drawn the most attention is this: MRI scans confirmed that hindbrain herniation — the brain abnormality most tightly associated with myelomeningocele spina bifida, in which part of the brain is pushed downward through the base of the skull — was completely reversed in every single case.
All six.
Hindbrain herniation is a structural change in the developing brain caused by the pressure dynamics created by the spinal defect. Its reversal had already been achieved by conventional fetal surgery in some cases — but seeing it resolved in every child, alongside the stem cell treatment and without the need for post-birth shunting, strengthens the case significantly.
'This paves the way for new treatment options for children with birth defects,' said Diana Farmer, who led the US trial at UC Davis.
The children will be followed until age six to evaluate long-term safety and — crucially — whether they show improved movement, bladder, and bowel function. Phase 2 of the trial, funded by the California Institute for Regenerative Medicine and Shriners Children's, is now underway and enrolling up to 35 patients. UC Davis has received nearly $15 million to carry out this next phase.
Spina bifida affects approximately 1,500 babies born in the United States each year and many thousands more worldwide. It is one of the most common birth defects that are not fatal. The goal of the CuRe Trial is not just to improve outcomes for these children — but to establish a model that could one day be applied to other birth defects treated in the womb.
For families who receive a spina bifida diagnosis during pregnancy, the future just became a little more hopeful.
For medicine, the in-utero era may have just taken its most significant step forward. 🌱