Kohn TP, et al. - Through a systematic review and meta-analysis of 37 European and North American studies (n = 12,492 oligozoospermic men), researchers discovered the prevalence of a complete Y-chromosome microdeletion (YCM) in oligozoospermic men with sperm concentrations of > 0–1, > 1–5, and > 5–20 million sperm/ml and ascertained whether 1 or 5 million sperm/ml was the most relevant sperm concentration threshold for YCM screening. In oligozoospermic men, all complete YCMs were AZFc microdeletions. Complete YCMs were significantly more prevalent in men with sperm concentrations of > 0–1 million sperm/ml as that of with > 1–5 million sperm/ml. In men with sperm concentrations of > 1–5 and > 5–20 million sperm/ml, YCMs were comparable. Hence, the majority of YCMs occurrence was concluded in men with sperm concentrations of ≤ 1 million sperm/ml, with < 1% recognized in men with > 1 million sperm/ml, in Europe and North America. The sperm concentration screening thresholds should be reconsidered by male infertility guidelines for North America and Europe in order to suggest testing for YCMs only for men with sperm concentrations of < 1 million sperm/ml.