Comparison of rescue ICSI at different times of non-IVF cycles in conventional IVF

Objective:To compare the clinical outcomes of rescue intracytoplasmic sperm injection(ICSI) at different times of non-IVF cycles in conventional IVF,explore its clinical application value and the optimal rescue time. Methods:93 cases receiving conventional IVF and rescue ICSI in the hospital from January 2007 to July 2009 were analyzed retrospectively;according to the different rescue ICSI times,they were divided into late rescue ICSI group(rescue ICSI was performed at 20～22 hours after conventional IVF,16 cases) and early rescue ICSI group(rescue ICSI was performed at 4～8 hours after conventional IVF,77 cases). Results:There was no significant difference in maternal age,duration of infertility and the mean number of oocytes retrieved every cycle between the two groups(P0.05).The normal fertilization rate,cleavage rate and pregnancy rate in late rescue ICSI group were significantly lower than those in early rescue ICSI group(52.0% vs 63.0%,87.5% vs 94.1%,0% vs 43.5%,respectively)(P0.05). Conclusion:Rescue ICSI is effective if fertilization is failure after routine IVF,and reasonable rescue time is the key of achieving ideal clinical outcome.