A new method to mature human eggs in the lab has been developed by Scottish scientists meaning that there may be hope of conceiving for women even after menopause.
The achievement of Edinburgh University researchers means that women undergoing cancer treatment, or wishing to delay motherhood to concentrate on their careers, may have a way of preserving their fertility in the next five to 10 years.
Dr Evelyn Telfer and her colleagues say that they have established a procedure to develop early stage follicles to a much later stage.
The researchers took pieces of ovary containing the follicles from six volunteer women who were giving birth by elective caesarean section, and exposed them to an artificial growth factor.
They revealed that about one-third of the follicles survived, and went on to reach an advanced stage.
"This is a significant step in developing immature eggs to maturity outside the body. Women who face infertility as a result of chemotherapy, or who want to put their biological clock on hold, could benefit from this system," the Scotsman quoted Dr. Telfer as saying.
"However, there is a lot more research to be carried out before this technique could be safely applied within a clinical setting," she added.
Normally, a woman undergoing cancer treatment has to have a piece of ovary removed and frozen for future transplantation, a procedure that carries the risk of reintroducing cancer cells to the patient.
They may also rely on fertility medication to produce eggs to be harvested for use at a later date, but this poses risks in delaying treatment, and defrosting the eggs does not always work.
Dr Telfer says that one alternative may be to maturing eggs in the laboratory may make it possible to screen them for cancer before they are returned.
In a report published in the journal Human Reproduction, the researcher says that women wishing to preserve their fertility past the menopause may also have their follicles stored for later use when they are ready to start a family.
She has revealed that in animal studies, eggs matured in this way appear to be completely normal and suitable for in vitro fertilisation.
However, her team have yet to confirm the same for humans.
"We believe there's good evidence that we can get normal oocytes (eggs], but of course you would never apply this technique clinically until you are sure," said Dr Telfer.