Scoring human sperm morphology using Testsimplets and Diff-Quik slides

The two staining methods should not be considered equivalent. Specifically, the lower reference limit established by the World Health Organization is not appropriate when sperm morphology is assessed by TS. The routine application of TS in the evaluation of sperm morphology is therefore not recommended because it leads to an overestimation of patients with sperm morphology values below the lower reference limit (4%), thus potentially influencing clinical decisions.