Outcomes of vitrified warmed day-4 embryos after day-3 cleavage-stage biopsy

The objective of this study was to compare the post-warming survival rates of biopsied and non-biopsied day-3 embryos vitrified on day 4 and to evaluate the clinical outcomes of following transfers. This study included 18 preimplantation genetic diagnosis (PGD) patients and 18 non-PGD patients treated between January 2005 and January 2009 who had not achieved live births during their fresh embryo-transfer cycles and whose surplus embryos were cryopreserved on day 4. The embryo survival rate after warming in the PGD and non-PGD groups was similar (53/59, 89.8% versus 55/64, 85.9%, respectively; difference of 3.9% 95% CI -7.3 to 13.4). Vitrified embryo-transfer cycles yielded no significant differences between PGD and non-PGD groups in implantation rates (12/46, 26.1% versus 9/47, 19.1%, respectively; difference of 6.9%, 95% CI -9.7 to 22.2), clinical pregnancy rates (11/18, 61.1% versus 9/18, 50%, respectively; difference of 11.1%, 95% CI -20.6 to 40.6) and live birth rates (9/18, 50% versus 6/18, 33.3%, respectively; difference of 16.7%, 95% CI -15.1 to 44.8). These results showed that, in PGD cycles, embryos can be vitrified effectively on day 4 after biopsy on day 3. (C) 2010, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.