The rate of multiple births resulting from IVF treatment is to be no more than ten percent, announced the Human Fertility and Embryology Authority (HFEA), in the final stage of its policy to reduce IVF multiple birth rates in the UK.

In a letter to all fertility clinics, chief executive of the HFEA, Mr Alan Doran, explained as of 1 October 2012, no more than ten percent of a centre's annual births from IVF, ICSI and gamete intra-fallopian transfer (GIFT) treatments should be multiple. Births from intrauterine insemination (IUI) or DI are excluded.

The decision is part of the HFEA's multiple births policy and sets the final maximum - fourth year - birth rate target. Ordinarily the new target rate is introduced in April, but the decision gives clinics extra time to adopt strategies and implement changes as the target rate comes down. The letter explains meeting the current year three target of 15 percent has been 'challenging'.

Figures indicate that on average clinics were under the year one and year two targets (24 and 20 percent, respectively), and were on course to meet the current annual target. The HFEA says multiple births present the single biggest risk to the health of mothers and children born after IVF. It maintains the risk can be avoided by transferring only one embryo into women with greater chances of becoming pregnant.

In 2007 the HFEA adopted a policy to reduce the annual rate of multiple births following treatment at fertility clinics over a four year period to no more than ten percent. All clinics were required to have in place a strategy to minimise multiple births by January 2009, when the HFEA set the annual maximum multiple birth rate at 24 percent. It has set yearly targets since then.

A group was set up in 2007 to promote a national strategy encouraging elective single embryo transfer (eSET). The strategy says clinics should offer eSET to women they identify as most likely to become pregnant, and therefore most at risk of having a multiple birth.

In the letter, Doran noted that since the introduction of the HFEA's policy, 'the proportion of eSET has increased, the multiple pregnancy rate has decreased and the overall pregnancy rate has remained steady'.

'The pregnancy rates from elective single embryo transfer are similar to the pregnancy rates from double embryo transfer', he said.

Chairman of the Association of Clinical Embryologists, Ms Rachel Cutting, welcomed the new target but cautioned: 'The problem most clinicians have is when patients are paying for a cycle, it is hard to convince them to have just one embryo put back, because they automatically think two will give them a better chance'.

Cutting also pointed out that it would be easier for clinics to meet the 10 percent target if the NHS was to fund three cycles of IVF per couple - as recommended by the National Institute for Health and Clinical Excellence.