ObjectiveTo evaluate the efficacy and safety of intracytoplasmic morphologically selected sperm injection (IMSI) versus intracytoplasmic sperm injection (ICSI) in in vitro fertilization (IVF) for couples with male factor infertility.

METHODSUsing the Cochrane system evaluation method, we searched MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov, and SinoMed and manually searched the reference lists of the included studies and relevant reviews for randomized controlled trials (RCT) comparing ICSI and IMSI published from 1992 to July 2017. We performed a meta-analysis on the included literature with the RevMan 5.3 software and subgroup analyses due to the prominent clinical heterogeneity of the patients.

RESULTSOf the 280 articles retrieved, 8 RCTs were included, involving 1 741 IVF cycles (842 cycles of IMSI versus 899 cycles of ICSI). There was no evidence for any significant difference between IMSI and ICSI in the live birth rate in the subgroup of infertility induced by pure male factors (RR = 1.31, 95% CI: 0.68－2.51; very low quality evidence from 1 RCT with 77 cycles) but an association of IMSI with an increased clinical pregnancy rate (RR = 1.46, 95% CI: 1.02－2.07; low quality evidence from 4 RCTs with 813 cycles), nor was there any evidence for that in the live birth rate (RR = 0.88, 95% CI: 0.60－1.31; low quality evidence from 1 RCT with 255 cycles) or clinical pregnancy rate (RR = 1.03, 95% CI: 0.86－1.23; moderate quality evidence from 3 RCTs with 851 cycles) in the subgroup of infertility caused by accompanying male factors.

CONCLUSIONSThe evidence is of low quality for the association of IMSI with an increased rate of clinical pregnancy and is not sufficient to support the routine use of IMSI in IVF for male factor infertility.