Patterns of Semen Quality and Clinical Referral for Sperm DNA Fragmentation Testing in Men Undergoing Fertility Assessment: A Real-World Observational Study

Male factor infertility contributes to around half of all cases of couple infertility, and semen analysis remains the main first-line investigation of male fertility. However, conventional semen parameters do not always provide a complete picture of sperm quality, and there is growing interest in additional tests such as sperm DNA fragmentation analysis. A retrospective observational study was conducted using anonymised clinical data collected from men undergoing routine semen analysis between January 2024 and May 2026. Semen analyses were performed according to the World Health Organization laboratory manual for the examination and processing of human semen using computer-assisted semen analysis (CASA). Macroscopic and microscopic semen parameters were recorded alongside morphology, laboratory assessment and referral for sperm DNA fragmentation testing using the Halosperm sperm chromatin dispersion assay. We retrospectively analysed data from 387 men who underwent routine semen analysis at Marylebone Diagnostic Centre, London, between January 2024 and May 2026. Samples were assessed according to WHO 6th Edition recommendations using computer-assisted semen analysis (CASA). Macroscopic and microscopic semen parameters were recorded, together with clinical classification and subsequent sperm DNA fragmentation testing using the Halosperm® sperm chromatin dispersion assay where indicated. The mean age of the cohort was 36.6 years (range 21–66 years). Although average semen parameters were generally above WHO lower reference limits, approximately 39–43% of men fell below the reference limits for key measures including sperm concentration, total sperm number, motility and morphology. Following review by the attending doctor, 61.0% of samples were classified as good, 30.0% as poor and 9.0% as very poor. Among the 170 men with available DNA fragmentation results, 25.6% of those classified as good were positive for increased DNA fragmentation, compared with 64.6% of the poor group and 82.1% of the very poor group. These findings show that conventional semen analysis remains valuable for identifying abnormalities and guiding further investigation. Importantly, sperm DNA fragmentation was also identified in a proportion of men whose routine semen assessment was considered satisfactory, suggesting that selective DNA fragmentation testing may add useful information to the conventional diagnostic pathway.