Potential of testicular sperm to support embryonic development to the blastocyst stage is comparable to that of ejaculated sperm

Abstract

Purpose: Recent studies have shown that improved clinical outcomes can be achieved by transferring blastocysts rather than cleavage-stage embryos. However, blastocyst transfer is not performed in all patients. The aim of this study was to compare clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles using testicular sperm (TE) with those of ICSI cycles using ejaculated sperm (EJ).

Methods: ICSI was performed using EJ in 141 cycles and TE in 37 cycles. Embryos were cultured for 5 days. The quality of embryos was assessed on days 3 and 5 before embryo transfer.

Results: Fertilization rate was 77.3% in the EJ group and 69.6% in the TE group (p < 0.05). The good-quality embryos on day 3 and 5 were not different between the EJ and TE groups. Embryos did not develop to blastocyst stage in 7 cycles of the EJ group (5.0%) and 2 cycles of the TE group (5.4%). There were no significant differences in blastocyst formation and blastocyst quality (46.1% vs. 47.5% and 5.7% vs 5.8%, respectively) on day 5 between both groups. Embryos were transferred in all cycles. Implantation (22.8 vs. 24.7%), clinical pregnancy (44.7 vs. 43.2%), miscarriage (21.7 vs. 33.3%), and delivery (76.5 vs. 66.7%) did not differ between EJ group and TE group. Clinical outcomes of ICSI were not different between the EJ and TE groups.

Conclusions: In conclusion, the potential of testicular sperm supporting embryonic development to blastocysts is comparable to that of ejaculated sperm. Therefore, this study suggests that blastocyst transfer can be a very useful assisted reproductive technique in the ICSI cycles that require the use of testicular sperm, and the clinical outcomes of the cycles are comparable to those of ICSI cycles using ejaculated sperm.

Keywords: Blastocyst; Ejaculated sperm; Intracytoplasmic sperm injection; Testicular sperm; Testicular sperm extraction.