A radical new approach to IVF is giving women more than a 50-50 chance of pregnancy for the first time.
Experts found that freezing embryos and waiting at least a month before implanting the first one helped women’s bodies to recover after the first stage of fertility treatment.
Doctors in Cambridge discovered that this pause in the process significantly boosted pregnancy rates.
An NHS clinic has now become the first to routinely adopt the procedure during IVF treatment after a trial found it increased its pregnancy rates by more than half.
Egg storage for in vitro fertilisation (IVF). Tube of eggs in cryogenic (frozen) storage, above
Women undergoing IVF usually have a fresh embryo transferred into the uterus within a week of the eggs being retrieved.
But the IVF clinic, which is part of Cambridge University Hospitals Trust, found that waiting for the body to recover improved a woman’s chances of conceiving.
Doctors say the high success rates mean that for the first time, couples can start fertility treatment knowing that it is more likely to succeed than fail.
The technique – which involves implanting the first embryo at least a month after undergoing the fertility treatment – resulted in pregnancy 62 per cent of the time, compared with 41 per cent using fresh ones straight away.
This is nearly double the national average rate of 36 per cent for using fresh embryos, according to figures from the Human Fertilisation and Embryology Authority.
Consultant embryologist Stephen Harbottle of Cambridge IVF, who led the research, said it is the most ‘exciting’ development he has witnessed in 25 years.
Women undergoing IVF usually have a fresh embryo transferred into the uterus within a week of the eggs being retrieved
‘The biggest angst with fertility treatment is that it’s always been that the treatment is more likely to fail than be successful,’ he said. ‘What we’ve been doing for years is put the best embryo into the worst environment so by being very well-meaning, we might actually have been holding back success rates for years.
‘We can start saying to people you’ve got a better than 50 per cent chance of success in most of the age groups. Across the board, data is showing a huge increase in success rates. It’s really exciting.’
Typically, a woman undergoing IVF is given follicle-stimulating hormones to encourage the production of around ten eggs in one go.
These are then harvested, fertilised with sperm and left to develop as embryos before one is transferred into the uterus. Any remaining successful embryos can then be frozen for use at a later date.
Doctors at the clinic noticed success rates were higher when using these frozen embryos rather than fresh ones immediately implanted.
They decided to explore further the process, known as frozen embryo transfer (FET), which was already being used in America and Scandinavia.
Last year they enrolled 147 women, aged between 24 and 45, to take part in an 18-month pilot of the ‘freeze-all’ process to see how it affected their fertility chances. As a result, 62 per cent of women became pregnant, with improved success rates for women of all ages, the researchers say.
They believe the success is largely because the body is allowed to return to normal after the disruptive hormonal treatment, which could create a hostile environment for the embryo.
The clinic has now received NHS approval to start offering the ‘freeze-all’ service to patients. It means patients from anywhere in the UK will be able to sign up for the treatment, which costs an additional £245 on top of the initial £2,500 for a round of IVF.
While there have been some live births, the trial is continuing, with many of the participants currently pregnant
Like many other clinical commissioning groups, Cambridgeshire and Peterborough health trust stopped free IVF in its region last September.
While there have been some live births, the trial is continuing, with many of the participants currently pregnant.
Commenting on the Cambridge technique, Stuart Lavery, a fertility expert at Imperial College London, said: ‘I think it’s an exciting area but I want to see much more evidence before I see a change in practice.’
How it helped me become a mother
Delighted: Kerrie Suarez with Emilio
Kerrie Suarez’s job as a nursery nurse served as a constant reminder of what she so dearly wanted.
But she was unable to have a baby because she suffered from endometriosis, which saw scar tissue build up in her fallopian tubes and stopped her eggs from being released.
Mrs Suarez, 34, who lives in Cheadle, Manchester, with her husband, Francisco, also 34, tried fertility treatment.
But after three IVF rounds on the NHS with fresh embryos, she still was not pregnant.
For their fourth attempt the couple decided to go private.
They opted for a ‘frozen cycle’ after doctors suggested the womb lining was more receptive to frozen embryos.
Mrs Suarez waited for two months before an embryo was implanted and then finally found she was pregnant. She had a 6lb 12oz boy Emilio, who is now ten months. ‘I still find myself staring at him in wonder,’ she said.