Scientists claim promises of stem cell fertility treatments are overhyped
Reported egg stem cells are not functional, says a new study
Stem cell research has delivered on many promises – some tissue grafts for bone, skin, and eye injuries are made with stem cells, and stem cell transplants have saved the lives of thousands of children with leukemia. But some promises are perhaps more prematurely stated than others – among them, the promise of enhancing women’s fertility using stem cells.
A Cambridge-based biotech firm named OvaScience claimed last spring that it has developed a fertility treatment using stem cells that achieved a pregnancy rate of 53% — out of a small study with 17 embryo transfers in women who previously failed multiple cycles of IVF, nine women became pregnant.
But many expressed skepticism of OvaScience’s results. John Eppig, a reproductive biologist at Jackson Laboratory in Bar Harbor, Maine told Science that he was “highly troubled” by the company’s claims, given that no controlled animal studies on whether or not this approach works, or if it has unintended consequences on offspring, have been published.
Now a new study published in Nature Medicine adds to the choir of critics. Swedish researchers from the University of Gothenberg and the Karolinska Institute performed a study showing that so-called “stem cells” taken from human ovaries did not generate any new eggs. In their study, the Swedish scientists replicated a protocol from a previous study, also published in Nature Medicine in 2012 by a team led by scientists from Massachusetts General Hospital and Harvard Medical School.
The new study, however, failed to find the same results as the one from 2012 – its authors claim the stem cell isolation procedure is aspecific and is not able to produce new eggs. Beyond this particularly study, though, these results hopefully serve as a wrist slap against overpromising extremely nascent treatments.
“It is not realistic to hope for a new treatment of female infertility with stem cells,” Professor Kui Liu of the University of Gothenberg, and one of the authors of the study, said in a press release.
Part of the problem is that scientists are still not sure whether these cells scraped from ovaries can even be considered stem cells – meaning whether or not they can generate new eggs. The standing belief until a few years ago was that women were born with all the eggs they were ever going to have. But the researchers at Mass Gen claim that the cells they found in ovaries are able to actually produce new eggs throughout life, with the promise of an infinite number of eggs for IVF treatments.
This spring, a couple in Canada gave birth to a baby using OvaScience’s technique, but scientists warn that it can be hard to pinpoint the stem cell treatment as the reason for the couple’s success – the mother may have just gotten lucky this try on her own.
Liu said in a press release that his team was motivated to publish their paper as an admonition of researchers who overinterpret their results and promise treatments before adequate testing has been done. “We believe that such ‘hype’ should cool down and we are warning society of irresponsible promises to patients and investors,” he said.