A prospective randomized study: day 2 versus day 5 embryo transfer

Ingrid Van der Auwera, Sophie Debrock, Carl Spiessens, Hilde Afschrift, Els Bakelants, Christel Meuleman, Luc Meeuwis, Thomas M. D'Hooghe
2002 Human Reproduction  
BACKGROUND: This randomized controlled study was performed in an unselected IVF/ICSI population to test the hypothesis that blastocyst transfers result in higher clinical pregnancy rates (CPR) per oocyte retrieval when compared with day 2 transfers. METHODS: Blind randomization for transfer on day 2 (group 1) or day 5/6 (group 2) was performed before stimulation. Oocytes and embryos were cultured in sequential media in 5.5% CO 2 , 5% O 2 , 89.5% N 2 and 90% humidity. A maximum of two embryos
more » ... transferred. RESULTS: The two groups were similar for age, IVF indication, number of treatment cycles, rate of ICSI/IVF, number of fertilized oocytes and number of embryos transferred. The CPR/oocyte retrieval was comparable in group 1 (32%) and in group 2 (44%), while the CPR/embryo transfer was significantly higher (P < 0.01) in group 2 (60%) than in group 1 (35%). Similarly, the implantation rate per embryo transferred was significantly higher (P < 0.03) in group 2 (46%) than in group 1 (29%). The cryo-augmented delivery rate/oocyte retrieval was comparable in group 2 (36.3%) and in group 1 (28.6%). CONCLUSION: This randomized study in an unselected population showed a significantly higher CPR/embryo transfer and a tendency toward a higher CPR/oocyte retrieval in patients receiving blastocysts when compared with day 2 transfers.
doi:10.1093/humrep/17.6.1507 pmid:12042269 fatcat:pss5pdpuifd3belnit5sdw5gpa