Late Fertilization of Unfertilized Human Oocytes in In Vitro Fertilization and Intracytoplasmic Sperm Injection Cycles: Conventional Insemination versus ICSI

摘要

>Purpose: The aim of this study was to evaluate the efficacyof intracytoplasmic sperm injection (ICSI) in comparisonwith conventional reinsemination using fertilization failedoocytes by conventional in vitro fertilization (IVF).>Methods: Oocytes were collected from patients of IVF orICSI cycles. Patients were grouped by fertilizationtechniques: group 1: conventional IVF; group 2: reinseminationafter conventional IVF failure; group 3: regular ICSI; group4: 1-day-old ICSI after conventional IVF failure; group 5:2-day-old ICSI after conventional IVF failure; group 6:re-ICSI after regular ICSI failure.>Results: In different insemination groups, normalfertilization rate was higher (P < 0.001) in 1-day-old ICSI (47.1%)and 2-day-old ICSI groups (40.0%) than in reinsemination(14.7%). Abnormal fertilization rate was higher (P < 0.05)in re-ICSI group (21.7%) than any other groups (range:0–8%). Cleavage rate was higher in 1-day-old (36.7%)and 2-day-old ICSI groups (36.0%) than in reinsemination(5.3%, P < 0.001) or re-ICSI groups (17.4%, P < 0.05).Pregnancy rate was 27.6% and 20.0% in conventional IVFand regular ICSI groups, respectively. However, 1-day-oldICSI (group 4) and 2-day-old ICSI (group 5) were attemptedonce embryo transfer (ET) but failed pregnancy occurredin each group.>Conclusions: In fertilization failure cycles, late ICSIincreases the rate of fertilization and embryonic developmentand may rescue the completely failed attempt of pregnancy.