Cautious Optimism as Scientists Grow Human Eggs From Immature Cells in the Lab

gizmodo.com - In a scientific first, researchers from the US and the UK have taken early-stage human egg cells and grown them to full maturity in the lab. It’s an important proof-of-concept that could eventually yield new infertility treatments for women.

Growing egg cells to full maturity in the lab isn’t anything new. Scientists have already done this with mice, where lab-grown oocytes, or developing female sex cells, have resulted in the birth of live offspring. Also, human eggs have been grown to full maturity in the lab before—but from cells that were already at a late stage of development. What makes the new study special is that it’s the first time scientists have achieved this with early-stage human eggs cells, setting the stage for fertilization by sperm—at least in theory.

Developed by researchers from the University of Edinburgh and the Center for Human Reproduction, the technique could eventually be administered to women whose eggs don’t develop fully in their bodies, and as a way to preserve a cancer patients’ ability to have biological offspring in cases where chemotherapy or radiotherapy has made them infertile. Conceptually, this breakthrough means a girl’s immature eggs can be recovered from her ovarian tissue, matured in the lab, and then cryogenically stored for future in vitrofertilization. Currently, a piece of ovary is removed before chemotherapy and then re-implanted after the treatments are done, but this introduces the risk of putting cancer cells right back into a patient’s body.