Elective single and double embryo transfer

The only efficacious measure to reduce the incidence of twin pregnancies is a policy of single embryo transfer. We report on our experience with elective single embryo transfer in good prognosis patients (age < 37 yrs, first two IVF cycles and at least two embryos of good quality). About one third of the couples meeting these criteria agreed to have a single embryo transferred, at least during their first IVF cycle. Pregnancy rates in women who had an elective single embryo transfer were only slightly lower than those in the group with elective double (i.e. more than two good quality embryos available) transfer (37.9% vs 40.0%) but the incidence of twins was 0.0% vs 27.1%. This strategy resulted in a substantial decrease of the twin pregnancy rate from 27.0 to 14.9%, without affecting the overall pregnancy rate. The conditions that are to be fulfilled before this policy can and will be applied on a large scale are discussed.