Intracytoplasmic morphologically selected sperm injection results in improved clinical outcomes in couples with previous ICSI failures or male factor infertility: a meta-analysis

The objective of this study was to perform the first meta-analysis to compare conventional intracytoplasmic sperm injection (ICSI) outcomes and intracytoplasmic morphologically selected sperm injection (IMSI) outcomes in couples with previous ICSI failures (IF) or male factor infertility (MF). A systematic review was performed by searching Medline database to identify articles reporting on the comparison between ICSI and IMSI outcomes in couples with IF or MF. The main outcome measures were the implantation, pregnancy and miscarriage rates. Thirteen studies fulfilled our predetermined criteria. The overall results of meta-analysis for implantation (OR: 2.88; CI: 2.13-3.89), pregnancy (OR: 2.07; CI: 1.22-3.50) and miscarriage rates (OR: 0.31; CI: 0.14-0.67) were in favor of IMSI in couples with IF. Additionally, the overall result of meta-analysis for implantation (OR: 1.56; CI: 1.11-2.18) and pregnancy rate (OR: 1.61; CI: 1.17-2.23) were in favor of IMSI in couples with MF. IMSI increases the odds of implantation by 50% and pregnancy by 60% in couples with MF. In light of improved clinical outcomes, we recommend promoting the IMSI method in couples with MF. Moreover, IMSI results in a 3-fold increase in implantation rate, a 2-fold increase in pregnancy rate and a 70% decrease in miscarriage rate as compared to ICSI in couples with IF, however, as no randomized evidence exists, randomized studies are needed to confirm the IMSI benefits in couples with IF.