Similar ongoing pregnancy rates after blastocyst transfer in fresh donor cycles and autologous cycles using cryopreserved bipronuclear oocytes suggest similar viability of transferred blastocysts.

This retrospective cohort study compared blastocyst transfers in 136 fresh oocyte donor cycles and 69 autologous cycles using blastocysts derived from culture of thawed bipronuclear oocytes, all with oocytes derived from patients or donors less than 35 years old. The autologous cycles and oocyte donor cycles had similar rates of implantation (65.9% vs. 62.1%, respectively) and ongoing pregnancy (79.7% vs. 75.0%, respectively), suggesting that autologous blastocysts transferred after post-thaw extended culture have viability and implantation potential that are comparable with those of blastocysts transferred in fresh oocyte donor cycles. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.