Alternative fertility treatments 'reduce chances of becoming pregnant'

Women are wasting their money if they pay for expensive genetic screening to improve their chances of pregnancy, new research suggests.

Controversial findings published in a leading journal indicate that Pre-implantation Genetic Screening (PGS) does not work.

In a study of 408 women aged 35 to 41, researchers in the Netherlands found that instead of increasing pregnancy rates, PGS reduced it.
Sebastiaan Mastenbroek, who led the Dutch team from the University of Amsterdam, said: "Up to now there has been a false belief in PGS. It sounds very plausible and a great technique in theory, but the evidence shows that in practice it's not."

PGS is normally reserved for older women hoping to start a family. It involves extracting cells from early stage embryos and screening them for chromosomal abnormalities that can prevent pregnancy.

Only those embryos which pass the test are implanted into the womb by In-Vitro Fertilisation doctors. The procedure is distinct from Pre-implantation Genetic Diagnosis (PGD) which looks for genetic defects that may be passed on to a baby.

Typically couples are charged £750-£1,000 for the service on top of the cost of normal IVF.

Currently, only eight clinics offer PGS in the UK, seven in London and one in the East Midlands.

Five clinics together carried out 103 PGS treatments in 2004, according to the latest figures available from the Human Fertilisation and Embryology Authority.

More than 1,700 IVF cycles with PGS were conducted worldwide in 2003, according to data collected by fertility experts. This is likely to be a wild underestimation since only 50 centres submitted figures.

A recent survey showed that 186 clinics in the US performed a total of 2,197 PGS cycles in 2005.

In the trial, 206 women undergoing IVF were given PGS and 202 were not. None knew which embryos had been screened, and neither did the doctors who carried out the implantations.

"We found that, at 12 weeks, 52, or 25% of the women in the PGS group were pregnant, whereas 74 or 37 per cent of the control group had an ongoing pregnancy," said Mr Mastenbroek, a Phd student at the Centre for Reproductive Medicine at the university's Academic Medical Centre.

"The women in the PGS group also had a significantly lower live birth rate - 49, or 24 per cent as opposed to 71, or 35% of the controls."

The findings were published today in the New England Journal of Medicine and simultaneously presented at the annual meeting of the European Society of Human Reproduction and Embryology in Lyon, France.

One explanation for the results might be the damage caused by removing a cell from an embryo only three days old, said the researchers.

Also, although one cell from the embryo might fail the test, the others could be healthy enough to make it viable. By discarding embryos screened out by GPS, doctors could be throwing away some which would have produced a successful pregnancy.

Earlier studies showing an improved pregnancy rate with PGS have generally been small and not carefully controlled, said the scientists.

Two previous randomised trials also showed a negative trend which had not proved significant only because of their small size, they said.

"PGS for.this group of women with the techniques we use now is not working," said Mr Masenbroek.

"For women coming to our centre it's a better option to just go for the regular IVF treatment instead of treatment with PGS screening. Whether better techniques will improve the outcome of PGS I don't know."

He said the best screening system remained the experienced human eye checking the likely viability of embryos by looking at their shape.

In Holland, GPS is not legally banned, but the professional guidance to clinicians is not to offer it. Other experts in the UK welcomed the study.

Alison Murdoch, Professor Of Reproductive Medicine, at the Newcastle Fertility Centre, said: "This is an important study that adds to the growing body of evidence showing that PGS is not beneficial. Furthermore, there is now concern that it might even reduce pregnancy rates.

"It illustrates the importance of undertaking properly controlled studies before new techniques are introduced as clinical procedures. Patients who pay for PGS as part of their IVF treatment should be made aware of these results."

Peter Braude, Professor of Obstetrics &£038; Gynaecology at Kings College London, said:

"At last a reputable group has been in the position to do a proper trial of assessment of PGS for infertile patients of advanced maternal age seeking IVF - the most common indication. The study has been well conducted and uses clinical outcome (continuing pregnancy and live birth) rather than the implantation rate as in some previous papers.

"The results clearly add weight to previous proper trials which demonstrate that PGS doesn't work for advanced maternal age. Vulnerable patients should no longer be exploited financially under the impression that it works."

Dr Richard Kennedy, spokesperson for the British Fertility Society, said: "This important study adds further evidence to support the view that PGS should not be routinely offered to women undergoing IVF treatment in the older age groups."

But the research was strongly criticised by one US geneticist who claimed it was seriously flawed.

Dr Dagan Wells, from Yale University, said the scientists had used methods which had not been part of normal practice for a decade and which were likely to damage embryos.

He also questioned whether the team had sufficient experience to carry out PGS effectively.

"I think it's indicative of a failure of the peer review process," he said.

"There have to be questions over the whole methodology used. There are questions over the patient selection and possibly the embryology, and certainly over whether this group has sufficient experience and whether the biopsy has caused extensive damage, which is likely.

"A paper like this is a tremendous disservice to patients because patients who could have benefited will now be advised not to seek this strategy."

A spokesperson for the HFEA said: "Anyone wishing to carry out preimplantation genetic screening (PGS) in the UK must have a licence from the HFEA.

"Clinics that are licensed to carry out PGS are required to follow HFEA guidance on the groups of patients they are able to offer it to and, equally crucially, must also provide very clear information to patients about PGS and its potential outcomes.

"There is an ongoing scientific debate about PGS, and there is more than one view among doctors about its efficacy.

"The HFEA, through committees such as the Scientific and Clinical Advances Group, carefully monitor this work."

source : www.dailymail.co.uk