By Mark Henderson, Science Editor
Times Online UK
Nov. 10. 2008
A new approach to fertility treatment that provides a safer alternative to IVF can deliver comparable pregnancy rates for suitable women, the only British centre to offer it has reported.
Of the first 38 British patients to be treated with the in-vitro maturation (IVM) technique, which does not require powerful hormonal drugs, nine have either given birth or have an ongoing pregnancy, according to figures released by the Oxford Fertility Clinic. It conducted 40 treatment cycles.
All the successful cases were among the 27 cycles performed on women under 35. This success rate, of 33 per cent, is almost identical to the 31 per cent that standard IVF achieves for this patient group. Another four women under 35 had a positive pregnancy test, but no foetal heartbeat was found by ultrasound.
The IVM technique, however, did not work at all well for older patients. Only one of the 13 cycles conducted on patients aged over 35 led to a pregnancy, and this was an ectopic pregnancy, in which the embryo starts to develop in the fallopian tube.
The findings, which were presented at the American Society of Reproductive Medicine conference in San Francisco, suggest that the treatment can be successful, but only for carefully-selected patients.
IVM involves removing eggs from a woman’s ovaries while they are still undeveloped, then maturing them artificially in the laboratory before fertilising them with sperm. It allows infertile couples to conceive without the need for the woman to be given fertility drugs to stimulate her ovaries before eggs are collected.
It has particular promise for the 30 to 40 per cent of infertility patients whose problems stem from polycystic ovary syndrome (PCOS), a condition that affects 10 to 20 per cent of women.
They are often advised against taking fertility drugs because they have a raised risk of ovarian hyperstimulation syndrome (OHSS), which can, on rare occasions, cause kidney damage or death. The syndrome occurs in one in 100 IVF cycles, but affects one in 10 cycles among women with PCOS.
Another potential application is in helping cancer patients to preserve their fertility before having chemotherapy that could otherwise leave them sterile. These women sometimes cannot take hormonal drugs because they might worsen their tumours, but could have immature eggs removed and frozen for use when they are in remission.
While more than 400 babies have been born from IVM worldwide, the Oxford Fertility Clinic is the only British centre licensed to perform it. The first British couple to conceive using the technique gave birth to twins last October.
Tim Child, of the Oxford Fertility Clinic, said: “Unstimulated IVM treatment is a viable alternative to standard IVF for women under 35 years of age who have ovaries of polycystic morphology. IVM avoids the potentially fatal complication of OHSS in this at-risk patient group.”
Geeta Nargund, of St George’s Hospital in South London, said that the evidence currently supports the use of IVM only for women with PCOS, a condition in which cysts cover the ovaries. A team in Denmark is trying the technique in women without PCOS but have not reported any results yet, she said.
The technique will not work in older women who have few eggs left in their ovaries because many eggs fail to mature in the laboratory and so a relatively high number is needed to start with, Dr Nargund said.