Abstract
BACKGROUND: Testicular microlithiasis (TM) is characterised by microcalcifications in the testes and has been associated with infertility. This has led to studies of semen analysis in men with the condition. This systematic review aimed to compare semen parameters in men with TM and those without. Men with classic TM (≥ 5 microcalcifications per sonographic image) were also compared to those with limited TM (< 5 microcalcifications per sonographic image). Additionally, testicular volume and hormone levels were analysed as secondary outcomes. This review was carried out according to PRISMA guidelines and registered on PROSPERO. The quality of included studies was assessed using the Newcastle-Ottawa Scale. RESULTS: Embase, MEDLINE, World of Science and Scopus were searched. Abstracts were screened against inclusion/exclusion criteria by two independent reviewers. Eligible studies included data on semen parameters in men with TM where semen analysis was done according to World Health Organisation recommendations. Studies with populations consisting of men with testicular cancer were excluded. After searching the databases, 137 papers were found and 10 studies involving 611 men with TM were included in the analysis. In the studies that compared sperm concentration in men with TM to controls, six (100%) found lower sperm concentration in the TM group. Six studies compared sperm motility, of which 4 (66.7%) showed lower motility in the TM group compared to controls. Five studies compared sperm morphology, with three (60%) finding a lower percentage of normal morphology in the TM group compared to controls. Six studies compared classic TM with limited TM. All six (100%) found a lower sperm concentration in the classic TM group compared to the limited TM group. Results also suggested that more extensive disease is associated with poorer sperm concentration. CONCLUSIONS: This review suggests that TM is associated with decreased semen parameters, particularly sperm concentration. However, clinical outcomes should be investigated by studying pregnancy rates in males with TM. Future research that controls for confounding variables, involves larger sample sizes, and utilises advanced sperm function tests is also advised. Further research is important for establishing clinical guidance and suggestions for fertility follow-up in men with TM.