Double-stranded sperm DNA fragmentation assessed using comet assay is associated with recurrent pregnancy loss.

RESEARCH QUESTION: Do men attending a recurrent miscarriage clinic have high double-stranded sperm DNA damage compared with a sperm donor population?

DESIGN

This prospective cohort study included 100 men attending a recurrent miscarriage clinic, and 81 sperm donors from a European sperm bank who had proven fertility. All semen samples were evaluated using the Examen Lab alkaline (Exact) comet assay, which identifies the global (single and double strand) DNA damage, and the neutral (Extend) comet assay, measuring only double-stranded sperm DNA fragmentation (dsSDF).

RESULTS

Semen analysis showed that 66 male partners of women with a history of recurrent miscarriage were classified as being within normal parameters. Of these, however, 66 men (61%) had raised global SDF, and 52% had raised dsSDF. When evaluating each test separately, the Exact comet (global SDF) assay presented an area under the curve (AUC) of 0.690 (95% CI 0.623-0.756), with the neutral Extend comet (dsSDF only) assay having an AUC of 0.876 (95% CI 0.834-0.914), and the incidence of damage showed an improved AUC of 0.909 (95% CI 0.874-0.940).

CONCLUSIONS

This study of male factor SDF in a large cohort of men attending a recurrent miscarriage clinic, where they are rarely the focus of clinical investigation, shows a strong association with dsSDF and male factor-driven miscarriage contribution, highlighting the importance of male investigation in couples experiencing recurrent pregnancy loss.