You’ve probably heard before that your supply of eggs is finite—we’re born with all the eggs we’ll ever have, and left with a dwindling number as we age. That’s been the prevailing wisdom for about 60 years. But Harvard researchers are now saying that young women’s ovaries contain very rare stem cells that are capable of producing new eggs—which could change the whole fertility timeline drastically.
“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly.
Apparently a lot of other scientists are skeptical of Tilly’s work. He first reported in 2004 that adult female mice carried some egg-producing stem cells in their ovaries. His latest study, published yesterday in the journal Nature Medicine, looked at whether the same was true in healthy human women.
Tilly and his team were able to use frozen ovaries donated for research by 20-somethings undergoing sex-change operations. After finding these rare stem cells in the ovaries, they tested the cells to see if they made eggs (they did) and injected them into pieces of human ovary. Within two weeks, egg cells began forming.
This doesn’t mean these egg cells would necessarily mature into ‘usable, quality eggs,’ said David Albertini, director of the University of Kansas’ Center for Reproductive Sciences.
But if they did, then freezing pieces of girls’ ovaries could mean stem cells to grow eggs in lab dishes, to be used for in vitro fertilization years later, said Tilly.
Further down the road, he wonders if it also might be possible to recharge an aging woman’s ovaries.
You’ve got to love some of the headlines this news has spawned:
That’s right, we’re smashing infertility up in here! … but, I mean, yeah, more or less. In a video made by Nature Medicine to explain the study, Tilly says:
“It opens up the chance that we might get to the point of having an unlimited source of human eggs … We can take 100 of them, and make a million of them. It would rewrite human assisted reproduction.”
The headline for a Scientific American post on the study was “Dogma Overturned: Women Can Produce New Eggs.” This is apparently pretty big.