Human eggs have successfully been grown in the laboratory for the first time, a breakthrough that can lead to improved fertility treatments.
From Earliest Stage To Maturity
Growing eggs in the laboratory from the earliest stage in the ovarian tissue up to full maturity has previously been done only in mice. Scientists were able to develop mouse eggs in the lab to a stage where these produced live offspring.
Researchers have also matured human eggs before, but these were from a relatively late stage of development.
In a feat published in the journal Molecular Human Reproduction on Friday, researchers removed human eggs cells from ovary tissue at the earliest stage of development and managed to grow these to a point that these are ready to be fertilized.
The work marks the first time that human eggs were developed outside of the body from the earliest stage to full maturity.
Holds Promise For Better Fertility Treatments
It may also eventually pave way for better fertility treatments in the future. It holds promise for young cancer patients who are at risk of becoming sterile because of medical treatments such as chemotherapy and radiotherapy.
Girls with childhood cancers can have their ovarian tissue frozen before they undergo treatment. This is then placed in to mature years later if the patient wants to bear a child. Abnormalities in the frozen samples, however, could be risky. The ability to make eggs in the lab offers a safer option for these patients.
"The ability to develop human oocytes from the earliest follicular stages in vitro through to maturation and fertilization would benefit fertility preservation practice," the researchers wrote.
Still Requires Refinement
The technique has potential uses, but it still requires refinement. For one, it is still inefficient. Only 10 percent of all the eggs used in the study completed the journey to maturity. The eggs have not also been fertilized, so researchers are still uncertain how viable these are.
"Molecular characterisation and chromosomal analysis is needed to show how these egg cells compare with normal eggs," said Azim Surani, from the University of Cambridge. "It might be of interest to test the developmental potential of these eggs in culture to blastocyst stage, by attempting IVF."
Nonetheless, experts are optimistic regardless that the method is still in its infancy.
"This early data suggests this may well be feasible in the future," said Ali Abbara, from Imperial College London. "[But] the technology remains at an early stage, and much more work is needed to make sure that the technique is safe and optimized before we ascertain whether these eggs remain normal during the process, and can be fertilized to form embryos that could lead to healthy babies."