In 2008, almost a quarter of IVF births were twins or more. A sustained collaborative effort between the fertility clinics, the HFEA, professional bodies and patients groups has reduced this to one in six IVF births. This work must continue in order to meet the target of one in ten.
HFEA licensed clinics are required to have a documented strategy to minimise multiple births. Its purpose is to reduce the annual rate of multiple births resulting from treatments at the clinic.
For patients who are aged 40 or under and using their own embryos no more than two embryos may be transferred in any treatment cycle. For patients who are aged 40 or over and using their own embryos no more than three embryos may be transferred in any treatment cycle except in exceptional circumstances. Refer to the HFEA’s Code of Practice multiple births guidance note for more information.
When implementing their strategy to minimise multiple births, clinics should consider the higher rate of multiple births from blastocyst transfers, in particular, blastocyst transfers resulting from ICSI cycles, and acknowledge that the live-birth rate does not increase with the transfer of three embryos but the risk of an adverse perinatal outcome does increase.
“Blastocyst transfer has become more widely used for all age ranges, however, centres should audit their strategy as double blastocyst transfer in those above the age of 37 does result in a high proportion of twin pregnancies”
Rachel Cutting, MBE, Principal Embryologist, Jessop Fertility
Members of the Multiple Births Stakeholder Group have produced a consensus statement on reducing multiple pregnancies following fertility treatments:
"There are far too many multiple pregnancies, with their intrinsic risk for the resulting children…the goal of medically assisted procreation must be a singleton pregnancy."
ESHRE Task Force on Ethics and Law. Ethical issues related to multiple pregnancies in medically assisted procreation Human Reproduction 2003; 18: 1976 – 1979
The British Fertility Society (BFS) and the Association of Clinical Embryologists (ACE) have issued professional guidelines on elective single embryo transfer (eSET). The guidance recommends the following approach to balance the risks of multiple pregnancy with the chance of a positive outcome:
The full publication can be found on the Human Fertility website. All centres should take the full guidance into account when reviewing their multiple birth minimisation strategies.