In an advancement that has the potential to change treatments for infertility forever, human eggs have been grown to maturity for the first time.
Researchers have now managed to turn immature human eggs into the fully developed version in the lab for the first time, but as of now, it’s still unclear whether the mature eggs are normal and can actually combine with sperm to make an embryo.
While it’s not readily apparent whether or not this new discovery regarding lab-grown human eggs is immediately practically applicable, it’s still “extraordinarily important,” according to Kyle Orwig, a stem cell biologist not involved in the study who is based at the Magee-Womens Research Institute at the University of Pittsburgh in Pennsylvania, and who spoke to Science Magazine. “It has real potential for application…we already have the patients.”
The applications of these lag-grown human eggs include women who have undergone chemotherapy, which has the potential to damage eggs beyond repair. This problem is especially prevalent in girls with cancer who have yet to hit puberty, and some choose to preserve a piece of ovarian tissue to later be placed back into the body to start making eggs. This is a complicated and risky choice, however, as it carries with it the possibility to reintroduce cancer cells. The lab-grown human eggs could provide a much safer and more viable option to improve human fertility in affected populations.
Science reports that ovarian tissues contain clusters of cells known as primordial follicles, which are essentially immature versions of egg cells. As the follicles enlarge and mature, Human eggs inside continue to mature as well. After the onset of puberty, the follicles rupture once per month in order to release a mature egg for fertilization.
The study that ended up growing human eggs in a lab environment was carried out over multiple steps with several different teams involved. Back in 2008, reproductive biologist Evelyn Telfer and her colleagues at the University of Edinburgh managed to take primordial follicles from ovarian tissue and bring them into a semi-developed state. Then, in 2015, a group of researchers at Northwestern University in Chicago created mature eggs from these partially developed follicles.
While both steps of this new process had been completed before, this most recent research with Telfer and her team represents the first time that the process has been completed from beginning to end within a single experiment. In order to obtain the results, the team took small samples from the ovaries of 10 different women who were undergoing an elective cesarean section. 87 follicles were isolated, which were then developed inside a “soup” of nutrients. After carefully extracting the immature eggs and surrounding cells from the follicle, they allowed them to further mature on a special membrane with even more nutrients. After this key step, nine out of the ten eggs were able to divide and halve their chromosomes – indicating that they have the capability to combine with sperm.
Although these findings are no doubt significant, this marks just the first step of research that will continue for years. With how fast the human eggs matured, there are problems that make them an iffy alternative when it comes to fertility treatments. Hopefully, with more time and information, growing human eggs in a lab will be the go-to method for couples with reproductive issues.
This research was published in the journal Molecular Human Reproduction.