IVF-ET中未受精卵母细胞行早期(5hrs)补救ICSI授精后胚胎发育潜能

Blastocyst formation competence of non-fertilized oocyte inseminated with 5hrs-early-rescue ICSI

在常规应用卵胞浆内单精子注射（ICSI）之前，常规体外受精（IVF）受精率低下很常见，大约有20％～35％的IVF患者会发生受精率很低（〈35％的卵子受精）甚至受精完全失败（所有卵子都不受精）。卫生部辅助生殖技术管理条例规定，在应用辅助生殖技术助孕的治疗中，对以女方输卵管堵塞、排卵障碍、子宫内膜异位症或不明原因等不孕因素为主的患者，

Routinely, IVF is performed for infertile couples without severe sperm defects and ICSI mainly for the couples with male factors. Before introducing ICSI in 1992, frequency of low fertilization rate （〈35%） in IVF was very high （20%-35% of patients）. Evidences suggest that sperm defects are the major contributors leading to fertilization failure in IVF. In contrast, oocyte factors are commonly associated with partial fertilization failure. To date, in our IVF center there were 204 unfertilized oocytes from 36 conventional IVF cycles with fertilization rate at 37.1%, including 9 cycles of total fertilization failure and 27 cycles of partial fertilization failure. In order to make full use of the oocytes and to generate more embryos for embryo transfer or cryopreservation, we routinely perform early rescue ICSI 5 hours after insemination. The Day3 top quality embryo formation rate and day5 blastocyst formation rate in the conventional IVF were 73.2 % and 61.7 %, respectively. Those unfertilized oocytes were re-inseminated by ICSI 5 h after conventional IVF insemination. The fertilization rate, Day3 top quality embryo formation rate and day5 blastocyst formation rate were 81. 4%,70.7% and 57.6%, respectively. The day5 blastocyst formation rate is lower in rescue ICSI group than that of conventional IVF group, but no significantdifference was observed （P〉0. 05）. Our results strongly suggest that 5hrs-early-rescue ICSI is an effectiverescue for the conventional IVF failure and more blastoeyst are generated for either transfer or eryopreservation. This will significantly minimize risk of fertilization failure in IVF patients and definitely cumulative pregnancy rate will be increased.