The first human eggs grown from human stem cells could be fertilized with human sperm cells later this year, potentially adding one more peg in the ladder toward reproduction sans human interaction. In this case it would entirely bypass a woman’s donation of her eggs. But it could also turn stem cells into an infinite loop, of egg cells into embryos into stem cells, and on and on, in a fractal-like repetition of reproduction.
In February, a study was announced involving Japanese women whose reproductive stem cells were donated because they were undergoing gender reassignment surgery. Researchers at Massachusetts General Hospital were able to coax these ovarian stem cellsinto becoming immature human egg cells, which were then incubated in mice so they’d have the proper ovarian structures. Now these same scientists, working with a team at Edinburgh University, want to fertilize them.
After sperm implantation, the scientists would watch the blastocysts develop into embryos for two weeks — the legal limit — and determine if they’re viable. Then these embryos would either be frozen or “allowed to perish,” according to the Independent. The tests would validate the stem-cell-derived human eggs, more properly called oocytes, and could serve as an early indicator of whether they could be used to eradicate human sexual activity and infertility.
Stem-cell derived oocytes could replenish the stocks of women undergoing menopause, or they could be used to allow infertile women to reproduce. The Independent goes so far as to mention an “elixir of youth,” wherein women of any age are full of stem-cell derived oocytes, remaining fertile and youthfully healthy forever.
The scientists argue that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients’ fertility. Today, Woodruff’s lab and others freeze pieces of girls’ ovaries before they undergo fertility-destroying chemotherapy or radiation. They’re studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown.
Still, this potential stem cell-based embryo construction still faces some hurdles — reproductive biologists are applying for a license to the Human Fertilisation and Embryology Authority in the UK. But if it’s approved, the eggs could be fertilized this year, according to the Independent.