Marcella Townsend remembers looking around the kitchen in shock. In the silence just after the explosion, before the pain kicked in, she found herself almost in awe of the crushed stove and the caved-in cabinets.

“It was like Bigfoot had walked across the counters,” she said.

In the aftermath of a propane explosion in 2021 at her mother’s house in Savannah, Georgia, Townsend spent more than six weeks in an induced coma in a burn trauma unit. She had second- and third-degree burns over most of her body, and her face had become unrecognizable.

Searching for a way to help her, surgeons turned to a rarely utilized tool: human placenta. They carefully applied a thin layer of the donated organ to her face, which Townsend said was “the best thing they could have done, ever.” She still has scars from grafts elsewhere on her body, but the 47-year-old’s face “looks exactly like it did before.”

During pregnancy, the placenta forms in the uterus, where it provides the fetus with nutrients and antibodies, and protects it from viruses and toxins. Then it follows the baby from the body, still filled with stem cells, collagens and cytokines that doctors and researchers have realized make it uniquely useful after birth, too.

Research has found placenta-derived grafts can reduce pain and inflammation, heal burns, prevent the formation of scar tissue and adhesions around surgical sites, and even restore vision.

And yet, of the 3.5 million placentas delivered in the United States each year, most still wind up in biohazard disposal bags or hospital incinerators. That flummoxes Townsend, who returned to her job as a surgical assistant with a new perspective.

“I’m constantly in these hospitals that don’t donate or utilize the placental tissue,” she said. “I hear the obstetrician say ‘I don’t need to send that to pathology or anything. Just trash it.’ I cringe every time.”

Decades ago, the medical community moved away from placenta usage due in part to fears brought on by the AIDS epidemic. Now, some doctors and researchers are arguing that the shift was misguided and that the placenta is an underused medical tool hiding in plain sight.

Because the placenta protects the fetus from the maternal immune system, its tissue is considered immunologically privileged: Even though it’s technically foreign tissue, placental grafts have been found not to prompt an immune response in transplant recipients. The placenta’s tissue also contains proteins and sugars that spur patients’ cells to multiply quickly, and the grafts have been shown to encourage rapid skin and tissue regrowth.

“We call it a healing factor, but a better way to put it is, it’s a regenerative factor,” said Dr. Scheffer Chuei-Goong Tseng, an ophthalmologist in Miami who has spent decades studying the use of placental grafts to treat eye injuries and diseases. “Healing is broad. You can heal but still scar. We are talking about healing almost without scarring.”

To make placental grafts, manufacturers collect free placentas from prescreened donors. The amniotic membrane, the innermost layer of the placenta that faces the fetus, is peeled off and sterilized. After it’s cut to a uniform size and shape, the tissue is deep-frozen, dehydrated or freeze-dried. To use it on a patient, doctors unwrap a packaged slice of membrane and lay it over a wound or incision — the graft can be held in place with sutures or, in some cases, just a dressing.

The Food and Drug Administration allows amniotic membrane grafts to be sold so long as they are “minimally manipulated” — meaning cleaned, preserved and not altered beyond being harvested from the placenta — and intended to serve the same function in the recipient as it did in the donor, a spokesperson for the agency said.

That means that since the amniotic membrane serves as a barrier between the fetus and mother, doctors can use the grafts as internal or external bandages.

Another FDA- sanctioned use is for treatment of chronic wounds. Tending to such wounds can be a matter of life and death for the millions of people with them. In such situations, placental grafts are emerging as a promising tool, reducing the likelihood of amputation and improving not only a patient’s overall life expectancy but also the quality of their remaining years, said Dr. Dennis Orgill, a professor of surgery at Harvard Medical School and the director of the Wound Care Center at Brigham and Women’s Hospital in Boston.

In one small study of 25 patients with foot wounds, for example, those treated with an amnion graft saw their wounds healed by an average of more than 98% in six weeks, while the wounds of those who received standard cleaning and dressing got nearly 2% bigger on average.

Phyllis Thomas, an 83-year-old from Carrollton, Missouri, was sure she’d lose her left leg to an infected wound that wouldn’t heal after surgery in 2017.

Doctors at the hospital tried radical measures to save the limb, including sealing 1,000 immature fly larvae inside and letting them go to work eating what Thomas called “the poison.” The maggots, in combination with antibiotics, brought the infection under control, but to close the wound, they used amniotic membrane grafts. Thomas’ leg healed completely.

When placed on difficult- to-heal wounds like Thomas’, the grafts seem to “change the nature of the wound,” said Dr. David Armstrong, a podiatric surgeon and wound care specialist with Keck Medicine of the University of Southern California. They can trigger what he called a “histologic reboot,” priming even the most damaged tissue to heal.

Dr. Jennifer Tsai, an optometrist in New York City, said amniotic membrane grafts are a valuable tool in her practice. In a patient whose eyes were burned after a bottle of bleach toppled off a shelf, she said, grafts “helped to regenerate that cornea rapidly.”

Beyond eye and wound care, some doctors are employing the grafts in creative ways. Neurosurgeons have used amniotic membrane grafts to repair the layer of connective tissue around the brain called the dura and to prevent the formation of scar tissue that can cause paralysis after spinal surgery.

The FDA is keeping a close eye on the wider field of regenerative medicine, which aims to restore tissues and organs damaged by disease or age. But when it comes to placental grafts specifically, the agency’s spokesperson said the FDA acknowledges the potential.

For now, graft companies only take placentas delivered by elective C-section. Bypassing the birth canal means less bacterial exposure. And C-sections, which account for nearly one-third of U.S. births, provide enough of a supply of placentas to meet the current demand.

But experts say that demand could be poised to rise. The use of amniotic membrane grafts is growing, albeit slowly, Armstrong said, because “medicine is, by its nature, conservative.”