US startup creates human egg cells from stem cells, but trials years away

US-based Conception said more work is needed to grow the eggs to full maturity, but called the achievement a 'major scientific advance' in reproductive medicine

A Berkeley-based biotechnology startup has claimed that it has generated the first early human egg cells derived from stem cells.

 

Conception Chief Executive Officer Matt Krisiloff announced the development on X on Tuesday, saying: "We've generated the first early human eggs derived from stem cells."

 

"This is a big deal -- the potential to redefine fertility is real," he added. 

Originally founded as Ovid Research in 2018, the startup is working to convert a type of stem cell known as an induced pluripotent stem cell (iPSC) into a human egg.

 

"We want to share an exciting update that we have generated the first early human egg cells ('primary oocytes') derived from stem cells. After performing a simple blood draw, we converted blood cells into stem cells, and then coaxed those stem cells into becoming miniature human ovaries that contain the early eggs," the company said in a blog post announcing the breakthrough.

 

The company added that while more work is needed to grow these eggs to full maturity, it considers the achievement "a major scientific advance".

 

“There's definitely more work to do, especially to evaluate if this technology is safe, but progress has been staggering. Healthy mice have been born this way, so we're optimistic of its potential,” Krisiloff said.

 

However, when an X user asked if she should hold off on freezing more eggs, Krisiloff clarified that the company remains far from clinical trials.

 

“Still a lot of work to do before we'd consider clinical trials, and ultimately need to be sober on if safety data will justify it -- if want to be as sure as possible, probably still a good idea to freeze at this point!” he said.

 

From blood cells to early human eggs

 

Conception explained its process of developing early human eggs, saying it all started with a simple blood draw.

 

It said researchers first converted blood cells into induced pluripotent stem cells (iPSCs) — a type of stem cell capable of developing into almost any cell in the body. After that, they “guided the iPSCs toward becoming each of the kinds of cells found in a developing ovary: ‘primordial germ cells’ are the cells that will eventually become eggs, and ‘ovarian helper cells’ are the supporting players that provide essential signals for the eggs".

 

“Together, these cells form ‘mini-ovaries,’ small 3-dimensional 'balls of cells' that mimic a true human ovary,” it said.

 

Conception said its researchers generate thousands of "mini-ovaries", containing millions of future egg cells, to study, improve, and benchmark their development in parallel.

 

What this could mean for reproductive medicine

 

If successfully developed for clinical use, the technology could significantly expand fertility treatment options. The process of producing viable eggs from stem cells, known as "in vitro gametogenesis” (IVG), has the potential to redefine reproduction worldwide, the company said.

 

Conception said this capability “could create freedom from biological and genetic” limitations. “From a simple blood draw, one could make as many healthy eggs as a family needs,” it said.

 

This could one day allow people to create viable eggs from a simple blood sample, potentially helping women with age-related infertility, cancer survivors who have lost fertility after treatment, and individuals born without functional ovaries, the company said. It added that the technology “could also eliminate the need for hormone stimulation and surgical egg retrieval required in conventional in vitro fertilisation (IVF).”

 

Clinical use remains years away

 

Despite the breakthrough, Conception says the technology is still far from being used in humans. The company has yet to grow its iPSC-derived follicles, or stem cell-derived egg structures, from the early primordial stage to the final "antral" stage, at which point the eggs reach full maturity.

 

It also plans to conduct extensive safety studies and further animal testing, noting that the threshold for clinical use is "incredibly high".