The first baby to be conceived from an immature egg that was matured in the laboratory and then stored in a freezer has been born in Canada, offering new hope of a family to girls and young women with cancer and those who are unsuitable for traditional fertility treatment.

The baby girl, who is now nearly a year old, is healthy and developing normally, and three other women are pregnant after having similar therapy at McGill Reproductive Centre in Montreal. The achievement shows it is possible to preserve fertility by freezing eggs without recourse to powerful hormonal drugs that stimulate the ovaries.

While hundreds of children have already been born from immature eggs that were ripened in a test tube before they were fertilised, the Canadian baby is the first to come from an artificially-matured egg that had also been frozen and thawed.

This makes the work highly significant for female cancer patients, particularly for pre-pubescent girls and women who have hormone-sensitive tumours, as these groups cannot take fertility drugs to induce their ovaries to produce mature eggs for storage on ice.

Instead, they can have immature eggs collected and cultured in the laboratory before freezing, which can be thawed later if they wish to start a family. On Sunday, a separate Israeli team reported that it is possible to extract immature eggs from the ovaries of girls as young as five, and the birth now indicates that it should be possible for these to be fertilised to conceive healthy children.

The success is also promising for other infertile women who cannot take fertility drugs, or who prefer to avoid them because of side effects that can include menopausal symptoms.

Patients who are infertile because they have polycystic ovarian syndrome (PCOS), which affects about one in twelve women of reproductive age, are often advised against these drugs, as they have a high risk of developing ovarian hyperstimulation as a result. On rare occasions, this can cause kidney failure and even death.

While PCOS patients can already benefit from having eggs matured in the lab and used while fresh, they can now freeze any that are left over for future attempts at IVF. The first four pregnancies were achieved from a trial of 20 Canadian women with PCOS.

Hahanel Holzer, who led the McGill team, told the European Society of Human Reproduction and Embryology Conference in Lyon that the pregnancies prove the technique gives a new range of options to women wishing to protect their fertility.

“It has the potential to become one of the main options for fertility preservation, especially for patients who cannot have ovarian stimulation and all patients who do not have enough time to undergo ovarian stimulation,” he said.

“However, we have to remember that these are only preliminary results from a small number of patients who were not cancer patients themselves. As for all methods for fertility preservation, they should be looked at as preliminary and experimental. We need to inform the patients about the early stage of these treatments without giving any false hopes.”

Independent fertility specialists welcomed the research, though they cautioned that more work is needed before freezing artificially matured eggs can be considered a standard treatment.

Lord Winston, Emeritus Professor of Fertility Studies at Imperial College, London, said: “This is important step forwards that could potentially help women with fertility issues, including those undergoing cancer treatment. But much more work needs to be done to ensure that there are not genetic defects in babies born using this technique.”

David Hodgson, Medical Director of the London Fertility Centre said: “This will enable both women requiring urgent collection of eggs to avoid high levels of oestrogen associated with standard IVF and also women with Polycystic ovarian syndrome to avoid complications of traditional IVF drug regimes. We at London Fertility Centre are always looking at ways to reduce the dose of IVF stimulatory drugs to achieve good pregnancy rates. Could this new technology herald “no drug” IVF in the future for the majority of women undergoing IVF?”

Dr Allan Pacey, Senior Lecturer in Andrology at the University of Sheffield and Honorary Secretary of the British Fertility Society, said: "This could be a very significant step forward in developing an effective fertility preservation strategy for women and young girls who are diagnosed with cancer before they have had an opportunity to complete their families. In comparison to men who can easily bank some sperm before cancer treatment, women have very few options and that really is not fair. Clearly, there needs to be more work done to make sure that the technique is safe, and that the children born from the eggs are healthy, but if this is done then this technique could become very important indeed.”

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