New guidelines for elective single embryo transfer in IVF treatment

The British Fertility Society (BFS) and the Association of Clinical Embryologists (ACE) have issued new guidelines in the journal Human Fertility to help UK clinics introduce an elective single embryo transfer (eSET) policy for IVF treatment. The release of these guidelines coincides with the BFS Summer College 2008, taking place on 2-5 September in Liverpool. Single embryo transfer is the only effective method to reduce IVF multiple pregnancy rate, the single biggest health risk to both mother and child associated with fertility treatment. UK practice in this area currently lags behind most of Europe and Australia, principally due to the lack of adequate state funding. For this strategy to be successful, it is crucial the funding situation is improved. The Human Fertilisation and Embryology Authority (HFEA) recently asked clinics to reduce multiple pregnancy rates from an average of 24% to 10% over the next three years. Currently in the UK, most fertility treatments involve transferring two embryos into the womb, increasing the likelihood of multiple pregnancy and the associated risks. These guidelines are designed to help clinics meet the criteria set by the HFEA, while not compromising the live birth rate. The guidelines recommend:

  • Patients should be carefully examined to assess if eSET is suitable for them. In the UK, 87% of multiple pregnancies occur in the first cycle of treatment, in women aged under 37. If patients are carefully selected (e.g. women under 37, in their first IVF cycle who have several high quality embryos), eSET plus subsequent frozen embryo transfer can be as effective as double embryo transfer, and does not compromise the likelihood of conception.
  • It is essential to combine an eSET policy with an effective frozen embryo replacement programme, to maximise cumulative live birth rates per stimulated cycle. This means spare high quality embryos harvested from an ovarian stimulation cycle can be frozen, stored and subsequently reimplanted if pregnancy does not result from the initial eSET. This avoids the need for women to undergo further costly cycles of ovulation stimulation to harvest more eggs. Urgent improvements in both facilities and funding in this area are needed to meet demand.
  • Three mild stimulation IVF cycles (collecting less eggs, creating fewer embryos and electively replacing one embryo) are as effective as two conventional stimulation cycles, result in fewer complications, and have proved more cost effective in other health care settings if the costs of multiple pregnancy are included. As most Primary Care Trusts fund only one cycle, couples are currently unlikely to choose this treatment, as live birth rate per individual cycle is lower.
  • Standard grading schemes for embryo quality could potentially greatly aid embryo selection. Although promising, new developments to assess embryo viability require more research before being introduced into clinical practice.
  • A simple algorithm based on embryo quality can help select those patients who would benefit most from eSET. Extending culture of embryos to day 5 after fertilisation (blastocyst culture) may assist in embryo selection for eSET.
  • To increase the eSET uptake, patient education is essential. Couples are more likely to accept eSET if state funding for more than one cycle of fertility treatment is readily available.
  • The HFEA should review its fees and data presentation structure to encourage the eSET uptake.
  • To reduce the multiple birth rate, it is absolutely critical that the Department of Health issues strict guidance to Primary Care Trusts to fully implement the NICE guidelines on fertility treatment. In overall terms, eSET will save the NHS money – extra spending on fertility treatment is more than counteracted by savings on treating the long-term health problems in both mothers and children caused by multiple births.

Mr Tony Rutherford, Chair of the BFS Policy and Practice Committee, said:
The key to success with this strategy is more NHS funding. The British Fertility Society strongly believes that the health benefits to children, the reduction in distress for families and the enormous cost savings for society make an overwhelming case for single embryo transfer in certain situations. Transferring only one embryo to those women most at risk of having twins is the only effective method to reduce the multiple birth rate after IVF treatment. It is imperative that elective single embryo transfer is made the norm for these women in the UK, as it is elsewhere in Europe.” “The only way in which this strategy can be effectively implemented for the benefit of both mothers and babies is for the NHS to increase funding to allow full implementation of the NICE guidelines on fertility treatment.”

Mrs Rachel Cutting, from the Association of Clinical Embryologists, said:
“New advances in embryology mean we can tackle the risks of multiple births much more effectively than ever before. These guidelines provide a clear, evidence based approach to judging embryo quality, the optimum time to transfer embryos, and the importance of an effective cryopreservation programme. The Association of Clinical Embryologists is committed to working towards a reduction in the number of multiple births, but this can only be achieved if adequate funding is provided by the state. Embryologists are key to helping to reduce multiple pregnancy.”

General information

Currently 1 in 4 IVF births in the UK results in twins or triplets, compared to 1 in 80 births following natural conception. Multiple pregnancy significantly increases the likelihood of miscarriage and death, prematurity and low birth weight in the infant. It can also lead to long term health problems for children, such as cerebral palsy, and risks to mothers such as pre-eclampsia, diabetes and heart disease. For more information see The NICE guidelines for fertility treatment state that infertile patients aged 23-39 should receive three full cycles of IVF, where a fully funded cycle includes cryopreservation and subsequent transfer of frozen-thawed embryos. Currently, these guidelines are fully implemented by less than 10% of Primary Care Trusts. –

Notes for editors
  • These guidelines will be published in full in the September edition of the journal Human Fertility 2008, 11(3): 1-16. DOI: 10.1080/146470802302629. Human Fertility is the official journal of the British Fertility Society. Human Fertility website:
  • The British Fertility Society is a national multidisciplinary organisation representing professionals practising in the field of reproductive medicine. We are committed to promoting good clinical practice and working with patients to provide safe and effective fertility treatment.
  • The BFS Summer College 2008 is taking place on 2-5 September in Liverpool.
  • The Association of Clinical Embryologists is the professional body of and for embryologists in the UK. ACE was founded in 1993 to promote high standards of practice in clinical embryology and to support the professional interests of embryologists working in the UK. For general information see:
  • For more information, please contact the British Fertility Society Press Office

Elective Single Embryo Transfer: Guidelines for Practice British Fertility Society and Association of Clinical Embryologists

Rachel Cutting1, Dave Morroll2, Stephen A Roberts3, Susan Pickering4 & Anthony Rutherford2 on behalf of the BFS and ACE; 1Centre for Reproductive Medicine and Fertility, Jessops Wing, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK, 2Reproductive Medicine Unit, Leeds Teaching Hospitals NHS Trust, Clarendon Wing, Leeds General Infirmary, Leeds, UK, 3Health Methodology Research Group, University of Manchester, Manchester, UK, and 4Edinburgh Fertility & Endocrine Centre, Royal Infirmary of Edinburgh, Edinburgh, UK.

Assisted conception treatment is the single most important cause in the increase in multiple pregnancy and births over the last 25 years. Multiple births are associated with significant peri natal morbidity and mortality. Europe has led the way in reducing multiple births by widespread adoption of an elective single embryo policy, which in Belgium is linked to an increase in state funding. Randomized controlled trials suggest that an eSET policy must include the ability to cryopreserve and transfer any remaining quality embryos to obtain parity with a double embryo transfer. This document provides a review of the available evidence with guidelines for practice, to help facilitate the introduction of an eSET policy in the UK