What Is the Normal Sperm Motility Level?
Jun 20, 2022
Source: Cainiu Health
Dr. Luo Yong
Introduction
Sperm motility refers to the percentage of spermatozoa in semen exhibiting progressive (forward) movement. Normal fertility is typically associated with ≥70% motile spermatozoa. A value <50% is considered abnormal—specifically, when the proportion of progressively motile sperm (grades a and b) falls below 50%, or the proportion of grade-a (rapidly progressive) sperm falls below 25%. Complete absence of sperm motility is termed necrozoospermia.
Sperm motility refers to the percentage of sperm in semen that exhibit progressive (forward) movement.
Sperm motility is generally classified into four grades: Grade 0 (d-grade): Sperm are immotile (no movement); Grade I (c-grade): Sperm exhibit non-progressive movement (e.g., in situ or circular motion); Grade II (b-grade): Sperm move forward slowly or sluggishly; Grade III (a-grade): Sperm exhibit rapid, straight-line, progressive movement.
Normal reference values are as follows: ≥25% of sperm should be Grade III (a-grade); or the combined proportion of Grade III (a-grade) and Grade II (b-grade) sperm should be ≥50%.
In men with normal fertility potential, the proportion of motile sperm should exceed 70%. A motile sperm percentage below 50% is considered abnormal—specifically, when the proportion of progressively motile sperm (a-grade and b-grade combined) falls below 50%, or when a-grade sperm alone constitute less than 25%. Complete absence of sperm motility is termed “necrozoospermia.”
Patients with low sperm motility should undergo seminal plasma analysis and thorough medical history evaluation to identify underlying causes—such as varicocele or genitourinary tract infection—and thereby determine the true etiology. Treatment should then be tailored accordingly.
