Whilst formulating the World Health Organization reference values for semen assessment for 2021, three key challenges were identified, namely the quality of semen assessments, the transparency and reporting of data and, lastly, the paucity of studies with primary data. There is an urgent need to address these issues and we present suggested solutions that will have a real-world influence on the next iteration of the reference values for semen assessments and andrology in general. [ABSTRACT FROM AUTHOR]