Comparable clinical outcomes and live births after single vitrified-warmed and fresh blastocyst transfer

Selective single-blastocyst transfer (SBT) in fresh cycles has been effective in reducing multiple pregnancies. However, we do not know whether this successful strategy of fresh transfer cycles is suitable for cryopreserved cycles. The present study was undertaken to evaluate the feasibility and value of SBT in vitrified-warmed cycles. Clinical pregnancy rate (CPR) was similar with vitrified and fresh SBT (46.61% versus 52.15% respectively). Of the pregnant patients, monozygotic twin, miscarriage and ectopic pregnancy rates were similar with vitrified and fresh SBT. For the newborns, no significant difference was observed in live birth, low birthweight, premature delivery and birth defects rates between vitrified and fresh SBT. With respect to the quality of transferred blastocysts (from BB to AA), a similar CPR and miscarriage rate was obtained for both vitrified and fresh SBT when a similar blastocyst cohort graded >= 3BB was transferred. The data show that vitrified SBT is an effective means of reducing multiple pregnancy and that comparable clinical outcomes and live births are achieved if single blastocysts graded >= 3BB are transferred for both vitrified and fresh SBT. These data should encourage clinics to evaluate their embryo transfer policy and adopt vitrified SBT as everyday practice. (C) 2012, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.