Live birth following transfer of a cryopreserved embryo generated from a cryopreserved oocyte and a cryopreserved sperm: Case report

As is the case with non-frozen oocytes, the efficient and successful use of cryopreserved oocytes in human assisted reproduction is, in part, dependent on the ability to apply selection criteria when choosing the 'best' embryos for transfer from a cohort. In many cases this, in turn, will necessitate the cryopreservation of non-transferred embryos to minimise the risk of multiple pregnancy. It is therefore important to establish that an embryo, generated by fertilization of a frozen-thawed oocyte, can be capable of surviving subsequent cryopreservation while retaining the potential for normal development. In this case report, we document the delivery of a normal male infant following transfer of a frozen-thawed embryo, generated by the fertilization of a frozen-thawed oocyte by a frozen-thawed sperm.