A woman whose cancer treatment left her infertile has given birth to a baby boy, through the first successful use of a new egg freezing technique.

The case study, reported in Annals of Oncology, combined two existing technologies: first, immature eggs were collected, matured in the lab and then frozen, then, five years later, the eggs were thawed and fertilised, before being implanted.

Professor Richard Anderson from the MRC Centre for Reproductive Health at the University of Edinburgh, who was not involved in the study, said 'getting eggs to mature successfully after removal from the ovary has been a challenge, so this is a very welcome positive step.'

The unnamed woman, who was 29 at the time, was about to undergo treatment for breast cancer, which is known to put fertility at risk. She was offered fertility counselling and ruled out the removal of ovarian tissue to preserve her fertility, as it is a very invasive procedure.  

The doctors at Antoine Béclère University hospital in Clamart, France were concerned that the standard IVF procedure of ovarian stimulation to mature the woman's eggs would exacerbate her cancer.

Instead, immature eggs were removed from the woman's ovaries shortly before she underwent treatment. The eggs were matured in the lab, in a process called in vitro maturation (IVM). Although this technique has been used before, the reported case is the first in which the eggs were frozen before fertilisation.

So far, the procedure is not very efficient, but it allows women who may not have another option to have babies. Future work is in progress to increase the efficacy, as currently, many embryos created from IVM eggs and subsequently frozen do not result in healthy pregnancies.

Freezing eggs and embryos for storage is a topic surrounded by complicated legislation.

However, highlighting a benefit of the technique, Professor Anderson said that freezing the matured eggs 'means that they remain the women's own property, without the complication that using a partner's sperm to fertilise them brings.'

Looking to the future, Professor Alastair Sutcliffe from UCL and Great Ormond Street Institute of Child Health, explained that 'caution must be considered in any new advance', but said this technique could be 'an additional tool for women who have the tragedy of cancer before reproduction to have their own genetic child'.

SOURCES & REFERENCES

Reproduced from BioNews with permission, a web- and email-based source of news, information and comment on assisted reproduction and human genetics, published by Progress Educational Trust.