Towards the elective replacement of a single embryo (eSET) in the United Kingdom

In the UK, the live birth rate after IVF in women aged less than 36 is >25%. The multiple birth rates in these women are excessive (20% to 25%). The perinatal mortality rate is increased significantly with IVF twins and triplets (8/1000 singletons, 20/1000 twins and 34/1000 triplets). Multiple pregnancies and births significantly increase the risks to the mother and the children, adversely affect family life and are economically disadvantageous to the couple and the wider community. The elective transfer of a single fresh embryo, followed if necessary by a single thawed embryo, in women at high risk of a multiple birth does not reduce the live birth rate and all but prevents the conception of twins and triplets.