Reproductive Outcomes in Patients with Severe Oligospermia Undergoing Intracytoplasmic Sperm Injection using Testicular Versus Ejaculated Spermatozoa

Abstract

Study question: To compare intracytoplasmic sperm injection (ICSI) outcome in patients with severe oligospermia using testicular versus ejaculated sperms. Summary answer: In patients with severe oligospermia,TESE should be considered as it offers higher pregnancy rates. What is known already: In infertile men with severe oligospermia (sperm concentration <5 million/mL) undergoing ICSI the choice between using repeatedly ejaculated sperm or recommending use of testicular sperm remains controversial. Testicular sperm have shown lower levels of DNA damage compared with ejaculated spermatozoa from the same individuals, however testicular sperm exhibit higher rates of chromosomal abnormalities. Study design, size, duration: Retrospective cohort study. Patients with severe oligospermia who underwent ICSI cycles with either tes-ticular or ejaculated sperm between January 2014 and December 2016 were included in this study. 205 couples met the study criteria after exclusion of cycles with mixed sperm sources. Participants/materials, setting, methods: Patients were divided into 2 groups (Group A) included 104 patients in which ejaculated sperms were obtained while (Group B) included 101 patients where fresh testicular sperms were extracted (TESE). The medical records of the included couples were reviewed and tabulated regarding demographic data, hormonal profiles and different semen parameters. After micro injection; fertilization rate, cleavage rates, embryo quality, implantation and pregnancy rates were evaluated and compared in both groups. Main results and the role of chance: There was no significant difference in the fertilization rate between the two subgroups (group A 67.93%, group B 68.01%, p = 0.960), however the cleavage rate of day 2 embryos was significantly higher when testicular sperm cells were used (47.37% vs 42.77%, p = 0.024∗). Implantation rate was slightly lower in group A compared to group B but without statistical significance (25.23% and 29.77% respectively, p = 0.292). There were no statistically significant differences between both subgroups regarding number and quality of day 3 and day 5 embryos. Pregnancy rate was significantly higher in group B where testicular sperm cells were used (54.45% vs 40.38, p = 0.044∗). Limitations, reasons for caution: Prospective randomized studies involving larger number of cases are needed to establish whether TESE should be performed as a routine step in infertile males with severe oligospermia or should it be limited to cases with previous ICSI failure. TESE remains a surgical intervention with possible associated risk. Wider implications of the findings: Sperm source can lead to better ICSI outcome in this certain group of patients; such finding may extend to include infertile males with abnormal DNA fragmentation testing.