Transferring just a single embryo in IVF to minimise the chance of riskier multiple births could increase the pregnancy rate among a group of women, research out today suggests.

Transferring just a single embryo in IVF to minimise the chance of riskier multiple births could increase the pregnancy rate among a group of women, research out today suggests.

Traditionally, IVF has involved implanting several embryos into the womb which increases both a woman's chances of having a baby but also her likelihood of having a multiple pregnancy - raising the risks of potentially fatal premature birth and pre-eclampsia and making surviving babies more prone to cerebral palsy.

Single embryo treatment, or Set, is safer because it does not carry the same level of risk, but the overall pregnancy rate has been lower than with multiple embryo treatment, causing couples and doctors to shun the method.

However, experts at Guy's and Saint Thomas' Hospital in London have now claimed Set can be more likely to result in the birth of a child than the multiple method.

The study gave one group of women multiple embryo transfers, which resulted in an overall pregnancy rate of 27% of which 32% were multiple pregnancies.

A second group who were given selected Set brought a 32% pregnancy rate with 17% multiple pregnancies.

Dr Yakoub Khalaf, who led the study, said: "It is a myth that single embryo transfer lowers the success rate of pregnancy. We believe firmly a twin pregnancy is not an ideal outcome. People think it is two for the price of one, but we see the heartache time after time. I would encourage every IVF clinic to look at our results when treating patients."

Professor Philip Steer, editor-in-chief of the Royal College of Obstetricians and Gynaecologists medical journal, which published the study today, backed that call: "The results of this study suggest Set can be the way forward for many women undergoing IVF."

However, Professor Richard Fleming, centre director at the Glasgow Centre for Reproductive Medicine, said: "It does not show what the potential pregnancy rate of the women who were given Set would have been if they had been given multiple embryos.

"Therefore to say that it's a myth that Set lowers the success rate is a simple error."