探讨常规体外受精(IVF)完全失败后，于授精后16～20 h行补救卵胞浆内单精子注射(ICSI)的临床应用可行性。

选择2010年1月至2013年11月在江苏省苏北人民医院生殖医学中心接受ICSI的211例不孕患者，共计243个周期为研究对象。根据受精方式，将23例行补救ICSI者纳入补救ICSI组(23个周期，在常规IVF受精完全失败后，于授精后16～20 h行补救ICSI)，将188例行直接ICSI者纳入直接ICSI组(220个周期，在周期中直接行ICSI)。采取回顾性分析方法，比较两组受精率、胚胎质量及临床结局。本研究遵循的程序符合江苏省苏北人民医院生殖医学中心人体试验委员会制定的伦理学标准，得到该委员会批准，分组征得受试对象知情同意，并与之签署临床研究知情同意书。两组患者平均年龄、不孕年限及平均获MⅡ卵数比较，差异均无统计学意义(P>0.05)。

①本中心自2010年1月至2013年11月，共行常规IVF为658个周期，受精完全失败率为5.8%；共行half-ICSI为19个周期，受精完全失败率为26.3%。②补救ICSI组正常受精率、卵裂率及优质胚胎率均显著低于直接ICSI组，且差异有统计学意义(P<0.01)，而两组间异常受精率及可利用胚胎率比较，差异均无统计学意义(P>0.05)。③补救ICSI组新鲜胚胎移植(ET)5个周期，仅1枚8细胞期胚胎于取卵第3天移植获得临床妊娠，但早期自然流产，临床妊娠率为20%(1/5)，另外4个周期(4细胞期胚胎第3天移植或8细胞期胚胎第4天移植)均未获得临床妊娠。补救ICSI组与直接ICSI组行冻融胚胎移植(FET)的胚胎种植率及临床妊娠率比较，差异均无统计学意义(χ²＝0.715，0.503；P>0.05)。

对不孕患者在常规IVF受精完全失败后，于授精后16～20 h行补救ICSI FET周期，可使胚胎发育速度与患者子宫内膜发育同步，获得较好的临床妊娠率。授精后16～20 h补救ICSI可作为常规IVF受精完全失败周期的补救措施。

To explore the possibility of clinical application of rescue intracytoplasmic sperm injection(ICSI) conducted 16-20 h after insemination when fertilization failured in conventional in vitro fertilization(IVF).

From January 2010 to November 2013, a total of 243 cycles of 211 barren patients undergoing ICSI in Reproductive Medicine Center, Northern Jiangsu People's Hospital were chosen as study subjects.According to different fertilization methods, 23 patients were bringing into rescue ICSI group(23 cycles, rescue ICSI conducted 16-20 h after insemination when fertilization failured in conventional IVF) and 188 patients were bringing into direct ICSI group (220 cycles, conducted ICSI directly in cycle). The study retrospectively analyzed and compared fertilization rate, embryo quality and clinical outcomes between two groups.The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Reproductive Medicine Center, Northern Jiangsu People's Hospital.Informed consent was obtained from each participant. There were no significant differences between two groups in average age, average infertile period and mean number of metaphase Ⅱ(MⅡ) oocytes(P>0.05).

①From January 2010 to November 2013, fertilization failure rate of 658 cycles of conventional IVF was 5.8% and fertilization failure rate of 19 cycles of half-ICSI was 26.3%.②The normal fertilization rate, cleavage rate and high-quality embryo rate of rescue ICSI group were lower than those of direct ICSI group, and there were significant differences(P<0.01). There were no significant differences between two groups in abnormal fertilization rate and available embryo rate(P>0.05). ③Only a 8-cell embryo which was transferred on ovum pick-up day 3 in 5 fresh embryo transfer cycles of rescue ICSI group got successful pregnancy, but miscarried early.The clinical pregnancy rate was 20%(1/5), other 4 cycles which 4-cell embryos were transferred on day 3 or 8-cell embryos were transferred on day 4 were not pregnant.When rescue ICSI group and direct ICSI group did frozen-thawed embryos transfer(FET), there were no significant differences between them in embryos implantation rate and clinical pregnancy rate(χ²=0.715, 0.503; P>0.05).

FET cycles of rescue ICSI conducted 16-20 h after insemination when fertilization failured in conventional IVF may achieve a better synchronization between embryo development and the endometrium, and get a satisfactory clinical pregnancy rate per transfer cycle.Rescue ICSI conducted 16-20 h after insemination when fertilization failured in conventional IVF could be a rescue step.