Single embryo transfer

The traditional policy of transferring more than one embryo in an attempt to increase success rates is responsible for the high numbers of multiple pregnancies associated with in-vitro fertilisation. Elective single embryo transfer is the most effective way of reducing multiples and the associated risks of maternal and perinatal morbidity. In selected patients, the combination of such a policy with the opportunity to transfer additional frozen thawed embryos in successive cycles can lead to cumulative livebirth rates similar to those following double embryo transfer. Appropriate eligibility criteria, improvement of cryopreservation techniques and funding arrangements are likely to increase the uptake of elective single embryo transfer.