The factors affecting male infertility: A systematic review

BACKGROUND: In recent years, the incidence of male infertility has increased worldwide. It is necessary to study the factors that influence male infertility in each area/region for better management. OBJECTIVE: To determine the factors affecting male infertility in the Iranian male population. MATERIALS AND METHODS: An online search was conducted in electronic databases including PubMed, Google Scholar, SID, and Scopus to identify articles on the factors associated with male infertility, published in English and Persian. The keywords used to perform the search included “factor", “epidemiology", “causes of infertility", and “male infertility". The search was conducted without a time restriction, up to April 2020. RESULTS: The search resulted in a total number of 691 studies. After an assessment of the articles, finally 14 studies were included in this study with a total number of 26,324 infertile males. The factors associated with male infertility included semen abnormalities, varicocele and testis disorder, smoking, exposure to heat, obesity, anabolic steroids, vascular abnormalities, anti-spermatogenesis factors, antidepressants, taking ranitidine and cimetidine, penile discharge and genital ulcers, painful micturition, occupational factors, alcohol, chronic disease, sexual disorder, Surgical and urological diseases, genetic factors and herpes infection. Among these, the semen and varicocele disorders were common in most studies. CONCLUSION: The present review suggests that the factors affecting male infertility in Iran are similar to those reported from other countries. The results of this study can be used in adopting appropriate strategies for infertility management in Iran.