Page URL:

One embryo as good as two for IVF success

1 November 2009
Appeared in BioNews 532

Transferring only one embryo during IVF treatment significantly reduces the risk of multiple births without considerably altering a woman's chances of conceiving and having a baby, report Swedish researchers.

In a study published in the New England Journal of Medicine, comparing single with double embryo transfer, 53 per cent of the women who had a single embryo implanted had a live baby, compared with 57 per cent of women who were implanted with two embryos.

The study involved 660 women, 330 of whom were implanted with a single fresh embryo. If that treatment cycle failed, a second embryo was implanted which had been frozen then thawed before use. The remaining 330 women were implanted with two fresh embryos.

Dr William Gibbons, the president of the American Society for Reproductive Medicine, said that these findings 'should provide comfort for those who want to perform single-embryo transfers that the pregnancy rates are equivalent'.

The study also showed that the rate of multiple births among women first implanted with a single fresh embryo was significantly lower, at just 2.3 per cent. Of the women implanted with two fresh embryos, 27.5 per cent gave birth to more than one baby.

IVF treatment has routinely involved the implantation of multiple embryos in order to increase a woman's chances of having a child, but as IVF procedures have become more advanced, doctors have been able to implant fewer embryos, with equally successful results.

However, multiple births are a common result, and incur health risks for both the mother and baby. Gestational diabetes, bleeding and pre-eclampsia, are all a risk for the mother, and the baby is at increased risk of cerebral palsy, birth defects and developmental delays.

The costs of IVF often prohibit more people choosing single embryo transfer, particularly in countries such as the US where treatment is not covered by national healthcare providers or insurance.

Moreover, 'the stress and disappointment of a failed cycle is hard to put a value on' says Dr Laurel Stadtmauer, an associate professor of obstetrics and gynecology at the Jones Institute for Reproductive Medicine in Norfolk, Virginia, US.

'This research adds further evidence confirming the value of elective single embryo transfer in assisted reproductive technologies,' said Richard Kennedy, a spokesman for the International Federation of Fertility Services.

Cumulative Live-Birth Rates in a Trial of Single-Embryo or Double-Embryo Transfer
NEJM |  29 October 2009
One Embryo as Good as Two in Second IVF Attempt
AJC |  29 October 2009
One embryo is best, in vitro fertilization study finds
LA Times |  29 October 2009
One Embryo Nearly as Good a Multiples for Pregnancy
Reuters |  29 October 2009
24 January 2011 - by Rosemary Paxman 
An international study has suggested elective single-embryo transfer (eSET) during IVF may improve chances of delivering a healthy baby compared to double-embryo transfer (DET), although women receiving DET are more likely to become pregnant in the first place....
11 October 2010 - by Ben Jones 
The National Institute for Health and Clinical Excellence (NICE) is considering tightening its guidelines on embryo implantation with the possibility that, in future, only single embryo transfers (SET) may be recommended....
22 March 2010 - by Dr Vivienne Raper 
Parents of twins, triplets or more are more likely to divorce or separate than other couples with children, according to a report commissioned by a multiple birth charity....
28 September 2009 - by Nishat Hyder 
A report published on 24 September 2009 by the Australian Institute of Health and Welfare ('the Institute') has indicated that although an increasing number of women are turning to assisted reproductive technologies (ART) to assist with pregnancy, the number of multiple births is decreasing....
23 February 2009 - by Professor Joep Geraedts 
Whilst reading the Commentary by Norbert Gleicher recently published in BioNews (1), we were surprised and saddened that the same arguments given at the ESHRE annual meeting (2) last summer in Barcelona, were repeated without a clinical counterpart. ESHRE wishes to reaffirm its response to Gleicher last July; the complications...
26 January 2009 - by Shantal Rajah 
Elective single embryo transfer (eSET) policy implementation has raised many issues among patients, IVF experts and fund holders. The main concern in relation to this policy is that we do not know how much, and by what percentage, it will reduce the pregnancy rate in our patients. The policy says...
26 January 2009 - by Sandy Starr 
This month sees the coming into force of new regulations by the UK's Human Fertilisation and Embryology Authority (HFEA), which seek to ensure that elective single embryo transfer (eSET) for women under 40 becomes standard practice in IVF treatment in the UK. Under these regulations, public and private fertility clinics...
20 August 2005 - by Professor Ian Craft and Dr Alan Thornhill 
The UK's Human Fertilisation and Embryology Authority (HFEA) recently announced that it is to review its rules on how many embryos can be implanted during IVF treatments. Transferring fewer embryos to all patients inevitably results in fewer multiple pregnancies, and we fully support measures making IVF safer. However, we recommend...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.