Recently presented at the 23rd annual meeting of the European Society of Human Reproduction and Embryology is the case of the first baby (born in Canada) to be created from an egg that had been matured in the laboratory, frozen, thawed and then fertilized.

According to Dr Hananel Holzer, who led the research team, is an assistant professor at the McGill Reproductive Center and coordinates the Center's fertility preservation programme:

"Freezing a woman's eggs (or oocytes) has become an important and integral part of fertility treatment, and the introduction of new freezing techniques such as oocyte vitrification has increased significantly both oocyte survival and resulting pregnancy rates.

In these circumstances, oocytes can be collected from the ovaries without hormonal stimulation, and the immature oocytes can be matured in the laboratory before being frozen or vitrified. But, until now, it was not known whether oocytes collected from unstimulated ovaries, matured in vitro and then vitrified, could survive thawing, be fertilised successfully and result in a viable pregnancy after embryo transfer.

We have demonstrated for the first time that it is possible to do this and, so far, we have achieved four successful pregnancies, one of which has resulted in a live birth. The other three pregnancies are ongoing. These results are preliminary and the pregnancy rate is probably associated with a learning curve; indeed three of the pregnancies were achieved in the last five patients."

We should remember however, that the procedures described above are for women of special circumstances - in this case, patients with polycystic ovarian syndrome (PCOS) who will not be capable of getting pregnant naturally later in their adult life.

Such procedures also apply to young girls or women with cancer who are likely to become sterile or undergo early menopause because of chemotherapy.

Find more details from the full report.