As one of the world’s first fetal surgeons, Diana Farmer has long been focused on the smallest of patients.

She specializes in treating birth defects inside and outside of the womb, treating congenital anomalies and cancer and performing airway and intestinal surgeries. In the late 1990s, she became the first woman in the world to perform open fetal surgery.

“You know, we didn’t know in the beginning whether we could even do it,” Farmer said.

In the nearly 40 years since the first fetal surgery, the field has evolved dramatically. Initially, fetal surgery was only used to treat fatal birth defects. Today, incisions are smaller, surgeries are safer, and outcomes for both mother and developing baby have improved. Farmer was immediately drawn to fetal surgery.

“The idea of being able to impact a disease at the very beginning, and change not just a life but a lifetime, was just the most exciting place to be,” she said.

Farmer attended Wellesley College, receiving her bachelor's in molecular biology. She completed medical school, her internship, and her initial residency at the University of Washington, Seattle. She completed a general surgery residency at UC San Francisco and a pediatric surgery fellowship at Children’s Hospital of Michigan before joining UCSF as a faculty member.

Farmer joined UC Davis Health in 2011 as the surgeon-in-chief of UC Davis Children’s Hospital and the chair of the Department of Surgery. She is a distinguished professor at the UC Davis School of Medicine and the Pearl Stamps Stewart Endowed Chair. Farmer’s arrival also led to the creation of the UC Davis Fetal Care and Treatment Center.

She was named to the National Academy of Medicine in 2011, and in 2023, Farmer was appointed to its membership committee. She serves as the vice chair of Section 6, which encompasses surgery, anesthesiology, ophthalmology and radiology.

Farmer is the first UC Davis Health faculty member to be assigned to a NAM leadership position. The appointment is considered one of the highest honors in health and medicine — Farmer called the appointment a tremendous responsibility.

Landmark clinical trials

As a surgeon-scientist, Farmer combines her expertise as a fetal surgeon and translational researcher to develop therapeutics for fatal and non-fatal birth defects. After working with stem cells for cancer research, Farmer realized stem cells might also be used to treat spina bifida.

Spina bifida, also known as myelomeningocele, is a birth defect where a fetus’ spine and spinal cord develop abnormally. Children born with spina bifida may experience paralysis, incontinence or cognitive abnormalities, depending on the severity.

Farmer and her team experimented for years — exploring induced pluripotent stem cells, nanofiber scaffolds, and neural crest stem cells — before settling on placental-derived stem cells. The team spent years in the lab perfecting an in-utero treatment in sheep and bulldogs before approaching the Food and Drug Administration to start a clinical trial in humans.

The landmark CuRe Trial or Cellular Therapy for in utero Repair of Myelomeningocele, is the world’s first clinical trial using stem cells to treat spina bifida before birth.

The CuRe Trial is the result of decades of Farmer’s work, including her work as a principal investigator on the $22 million Management of Myelomeningocele Study, or MOMS, which was selected as the clinical trial of the year in 2012 by the Society for Clinical Trials. The MOMS trial definitively showed that in-utero surgery was safe and improved the outcomes for children born with spina bifida.

“It immediately changed the standard of care,” said Farmer.

The CuRe Trial launched in spring 2021 with a combined $15 million grant from the California Institute for Regenerative Medicine and Shriners Children’s. On July 12, 2021, Farmer’s team performed the first surgery, surgically applying stem cells to the spinal cord of a still-developing fetus.

Almost four years into the trial, the team is closely monitoring patients for safety, watching as they reach developmental milestones, including the ability to walk. While it will take years for definitive answers, early results are promising.

Farmer believes her research could not have happened without collaboration across UC Davis. Farmer and her School of Veterinary Medicine colleagues collaborated closely in the early stages of the CuRe Trial, studying spina bifida in sheep and treating bulldogs.

“It has really been a spectacular, enriching part of my career here,” Farmer said. “That’s one of the things that brought me here — it was just really exciting to advance human health in the only University of California that had a vet school and had an agriculture school.”

Farmer also referenced the UC Davis School of Veterinary Medicine’s One Health Institute, highlighting the intersection of animals, people, plants, and the environment.

“This is just such a rich place to do science,” she added.

After decades as a pioneering leader in the field, she is optimistic about the future of fetal surgery and the power of regenerative medicine.

“I think we could treat many more diseases before birth — certainly many of the birth defects, many of the genetic diseases, like cystic fibrosis and sickle cell anemia,” she continued.

Farmer said regenerative medicine could also impact chronic diseases, including high blood pressure and diabetes.

“The future is going to be in cell and gene therapy.”