Efficacy Of Rescue Icsi After Conventional Ivf Failure

Objectives: The aim of this investigation is to evaluate the efficacy of rescue ICSI in mature oocytes after complete fertilization failure in conventional IVF.Methods: We retrospectively evaluated the outcomes of reinsemination by ICSI in 46 patients who underwent conventional IVF cycles and who showed complete and unexplained fertilization failure, at the Women's Health Reference Center IVF Unit, Sao Paulo, Brazil, from January 2004 to July 2008.Results: Among 661 IVF cycles performed in couples without male factor, complete fertilization failure was observed in 46 patients (6.95%). The mean age of these patients was 35.9 years. Among 240 oocytes retrieved, 204 were MII (85%) and rescue ICSI was performed in 176 oocytes, approximately 24 hours after the initial IVF procedure. After rescue ICSI, the rates of fertilization and cleavage were 60.23% (n = 106) and 62.23% (n = 66), respectively. The embryo transfer was performed in 24 patients (52.17%). Two single clinical pregnancies (gestational sac with heartbeats) were achieved (8.33%), both of which resulted in live births. The implantation rate was 3.0%.Conclusions: Despite the limited success of rescue ICSI in terms of implantation rate (3.0%) observed in this study, the rates of fertilization (60.23%), cleavage (62.23%) and clinical pregnancy (8.33%) suggest that emergency rescue ICSI after complete failure in conventional IVF can be performed in order to avoid cycle cancellation. It remains to be determined whether rescue ICSI in combination with preimplantation genetic diagnosis, which was not carried out in our study, would furthermore improve the results of this procedure.