Use of testicular versus ejaculated sperm for intracytoplasmic sperm injection among men with cryptozoospermia: a meta-analysis

Abstract

The question of whether or not to proceed with intracytoplasmic sperm injection (ICSI) using ejaculated or testicular sperm among men with cryptozoospermia remains unanswered. Our aim was to examine the relationship between sperm source in men with cryptozoospermia--ejaculated versus testicular--and ICSI outcomes. Meta-analysis. A systematic search was performed in PubMed (inception to March 2015). Search terms included variations on: ‘cryptozoospermia’, ‘severe oligozoospermia’, ‘oligo-astheno-teratozoospermia’, ‘ejaculated’, and ‘testicular’. Inclusion criteria included human studies comparing ICSI outcomes among men with cryptozoospermia who underwent consecutive ICSI cycles using either testicular or ejaculated sperm. Primary outcomes included fertilization rate or pregnancy rate. The secondary outcome was maternal age at time of ICSI. Meta-analysis of weighted data was performed using RevMan 5.3 and a random effects model was employed, due to clinical heterogeneity among the studies. Results are reported as odds ratio (OR) or weighted mean differences (WMD) with 95% confidence interval. A total of 773 studies were identified, of which five cohort studies were included for analysis.(1-5) The included studies examined either pregnancy or fertilization rates, encompassing 272 ICSI cycles and 2547 injected oocytes, respectively. There were no differences in the ICSI pregnancy rates (OR 0.44, 95% CI: 0.12-1.64, p=0.22, I2=69%) or fertilization rates (OR 0.84, 95% CI: 0.63-1.11, p=0.22, I2=69%). A non-significant trend toward increasing maternal age at the time of ICSI with testicular sperm was noted (WMD 3.03, 95% CI: -.04-6.09). Post-hoc power analysis revealed pβ <20% for pregnancy rate analysis and pβ<10% for fertilization rate analysis. Thus, the risk of Type II error was low. Among men with cryptozoospermia, the use of testicular sperm was shown to have no advantage in regard to ICSI fertilization or pregnancy rates as compared to ejaculated sperm. Thus, men should be encouraged to proceed with ICSI cycles using ejaculated sperm preferentially over invasive surgically-extracted testicular sperm.