Table 2.

Summary of changes in the 6^th edition of the World Health Organization manual of human semen analysis compared to the previous 5^th edition.

	Change
Term	Standard test → Basic examination Optional test → Extended examination Research test → Advanced examination
Basic Examination	Addition of semen odor examination Categorization of progressive sperm motility into rapid and slow A systematic approach to sperm morphology assessment Sperm vitality is indicated if sperm total motility is less than 40% Removal of terms such as normozoospermia, oligozoospermia, asthenozoospermia, teratozoospermia, and necrozoospermia
Extended Examination	Assessment of leukocyte and antibodies are considered an extended examination. Additional discussion on sperm DNA damage and genetic testing, although no clear indications are defined for both tests. TUNEL, SCD, and acridine orange flow cytometry for SDF are listed as useful tests in clinical practice
Advanced Examination	Removal of human oocyte and zona pellucida binding, as well as oocyte penetration tests Addition of seminal oxidative stress testing Better explanation of the principle of CASA

CASA: computer-assisted semen analysis. SCD: sperm chromatin dispersion. SDF: sperm DNA fragmentation. TUNEL: terminal deoxynucleotidyl transferase (dUTP) nick end labelling.