A new method of assisted conception has been hailed as a safer and equally effective alternative to IVF for certain groups of women undergoing treatment.  The Oxford Fertility Centre revealed this week that of the 40 women they treated between February 2007 and March 2008 with in-vitro maturation (IVM), the nine successful cases were all among the 27 women under 35; a success rate of 33 per cent. Conventional IVF has a 31 per cent success rate for this group of women.

IVM does not require the powerful hormonal drugs used in IVF which stimulate the ovaries to produce mature eggs; instead, immature eggs are removed without the use of drugs and matured in the laboratory before being fertilised. As fewer drugs are used, the cost of IVM would be significantly less than IVF, £1,700 compared with around £4,300.

The IVM process promises to be safer than IVF because it does not risk the potentially fatal ovarian hyperstimulation syndrome (OHSS), a build up of fluid in the lungs and abdomen sometimes triggered by the hormonal drugs involved. This news will be particularly welcome to women with polycystic ovary syndrome (PCOS), which affects 10 to 20 per cent of women, and who are at higher risk of developing OHSS.

'Unstimulated IVM treatment is a viable alternative to standard IVF for women under 35 years of age who have ovaries of a polycystic morphology', said Dr Tim Child, of the Oxford Fertility Centre, who presented the research at the American Society of Reproductive Medicine conference in San Francisco. 'IVM avoids the potentially fatal complication of OHSS in this at-risk patient group.' Dr Child attributed the significant improvement in success rates for IVM to better laboratory procedures and patient selection. 'I'm not sure we will ever get better than IVF but the aim is to achieve the same success rate', he said.

Another patient group who may benefit from IVM is cancer patients due to undergo chemotherapy. Tumours can be worsened by the hormonal drugs used in IVF, whereas the removal and storage of immature eggs in the IVM process would not adversely affect cancer patients and enable them to use their stored eggs once in remission.

Geeta Nargund from St George's Hospital in South London said that the technique is not appropriate for older women since fewer eggs remain in their ovaries. Many eggs fail to mature in the laboratory and so a higher number of eggs are needed to begin with.