Reference level for sperm morphology

Although an update to the Laboratory Manual for the Examination and Processing of Human Semen was published in 2021 (constituting the sixth edition), the criteria of the fifth edition are still taken into account. Therefore, according to the World Health Organization (WHO), a semen analysis is considered normal if there is at least 4% normal sperm.

Furthermore, if Kruger criteria are taken into account, the percentage of sperm with normal forms must be greater than 15% since they are stricter criteria for sperm morphology.