Frozen embryos generated from surgically retrieved sperm from azoospermic men: are they clinically viable?

Abstract

Purpose: To assess the viability of frozen-thawed embryos derived from intracytoplasmic sperm injection (ICSI) in azoospermic men.

Methods: Retrospective analysis of 154 consecutive ICSI cycles using surgically retrieved sperm from azoospermic men and case-control comparison of subsequent frozen transfer cycles with those using embryos generated from ejaculated sperm.

Results: Patient and fresh cycle characteristics were similar in both groups. There were no differences between the two groups in the proportion of pronucleate (54% and 62%), and cleavage-stage embryos thawed (46% and 38%), post-thaw survival rates (retrievals: 69%; ejaculated: 73%) or quality of frozen embryos subsequently transferred. Implantation was significantly lower in frozen cycles where embryos were generated from surgically retrieved sperm (0% versus 11.5%; p = 0.03). Both clinical pregnancy rate (5% versus 21%) and live-birth rate (0% versus 21%) were lower in this group, but only the difference in LBR reached borderline statistical difference (p = 0.10).

Conclusion: This small series demonstrates a significant impairment in implantation in FET cycles using embryos generated from surgically retrieved sperm and a trend towards a poorer pregnancy outcome.