A study on late intracytoplasmic sperm injection after total conventional in-vitro fertilization failure

Objective: The aim of this study was to evaluate the application of late intracytoplasmic sperm injection(L-ICSI) using total fertilization failured(TFF) oocytes by conventional in vitro fertilization(IVF).Methods: Between January 2002 and February 2007,TFF oocytes by conventional IVF in 86 couples were performed intracytoplasmic sperm injection.In the second trial,14 couples with unexplained infertility or endometriosis were treated by Half-ICSI in 2006.Results: The fertilization rate of L-ICSI oocytes(57.2%) was lower than that of ICSI oocytes right after retrieval(73.6%)(P0.01),the number of transferable embryos decreased,the clinical pregnancy and delivery rate were very low(only 1/86).For 31 couples who showed unexplained TFF on the first conventional IVF attempt and failed to conceive after L-ICSI,a second attempt was carried out,in which ICSI was used as the only insemination technique on the day of oocyte retrieval.13 viable pregnancies were achieved,yielding a 41.9% pregnancy rate per cycle.Fertilization rate and cleavage rate were similar in L-ICSI and in Half-ICSI,whereas clinical pregnancy rate was significantly higher in Half-ICSI than that in L-ICSI(50.0% vs 1.2%,respectively).Fertilization rate and clinical pregnancy rate in Half-ICSI were not significantly different from those in fresh cycle ICSI(67.6% vs 71.2% and 50.0% vs 38.2%,respectively).Conclusions: Our results suggest that L-ICSI can hardly be a successful rescue for the conventional IVF failure.We recommend the use of Half-ICSI to treat suitable indicated infertile couples to avoid TFF and to improve clinical pregnancy rate.