"By targeting this very high risk group (best prognosis patients), which constituted only 20% of our patients, we have been able to halve our multiple pregnancy rates, and, contrary to the sceptics´ opinion, not only did we maintain our success rates in the overall programme but we managed to increase them over the course of the study."
Dr Yacoub Khalaf Consultant in Reproductive Medicine & Surgery, Guy's Hospital.
Multiple pregnancies and births are the single biggest risk to mothers and children during IVF treatment. For detailed information on the risks to both mothers and children that are associated with multiple pregnancy and birth. For more information see What are the risks?.
It should be stressed that the high incidence of IVF twins would be avoided if SET was used for suitable patients. IVF children would then have almost the same chance as naturally conceived children of being born as full-term and normal birth weight singletons.
Although in vitro fertilisation (IVF) births account for only a small percentage (1.3%) of all births nationally, over 20% of all multiple births are IVF births. This means that IVF births contribute a disproportionately large number of multiple births to the overall rate.
In countries where eSET is more widely used, experience shows that when given to suitable patients and followed up by treatment with frozen embryos, eSET has little effect on the live birth rate, when compared with multiple embryo transfer.
However, in the UK, the availability of funding for follow-up treatment with frozen embryos varies. For more information see Defining a cycle.
In 2003 Sweden had the greatest use of SET and the lowest multiple birth rate, but still ranked 4th on live birth rates. Sweden’s multiple birth rate is now below 5%.