WHO 2021 reference values
The WHO sixth edition (2021) updated reference ranges based on a large multi-centre study of fertile men. Key lower reference limits include: volume ≥ 1.4 mL, concentration ≥ 16 million/mL, total sperm count ≥ 39 million, progressive motility ≥ 30%, total motility ≥ 42%, and normal morphology ≥ 4% (Kruger strict criteria).
A single abnormal semen analysis does not confirm infertility. Significant intra-individual variability exists, and a repeat sample 2–3 months after the first is often recommended before drawing conclusions.