Intracytoplasmic Sperm Injection at Different Time Points After Conventional in Vitro Fertilization to Rescue Unfertilized Oocyte

Abstract

Objective To compare the outcomes of rescue intracytoplasmic sperm injection (ICSI) in 6 h and 22 h after conventional in vitro fertilization (IVF) to rescue unfertilized oocyte. Methods From June 2004 to November 2008, a total of 31 failure IVF cycles were included into this study. Among them, rescue ICSI was performed on 6 h after initial IVF of 15 failure IVF cycles (between June 2004 and August 2007) (6 h group), 22 h after initial IVF of 16 failure IVF cycles (between August 2007 and November 2008) (22 h group). The rates of fertilization and cleavage, embryo quality, implantation, and pregnancy rates after rescue ICSI were analyzed and compared between two groups. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Yantai Yuhuangding Hospital. There had no significant differences between two groups among average, infertility duration, and so on (P>0.05). Results The fertilization rate in 6 h group (77.8%, 70/90) was significant higher than that of 22 h group (47.5%, 58/122) (P<0.01). The cleavage rate in 6 h group (98.6%, 69/70) was also significant higher than that of 22 h group (79.3%, 46/58) (P<0.01). And the clinical pregnancy rate in 6 h group (43.8%, 7/16) was higher than that of 22 h group (0, 0/15) with significant difference (P<0.05). Conclusions It was competitive to rescue ICSI on oocytes with fertilization failure in 6 hours than 22 hours after conventional IVF. Key words: in vitro fertilization; fertilization failure; rescue intracytoplasmic sperm injection; second polar body