What Is the Normal Sperm Motility Level?
Jul 06, 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 associated with ≥70% motile spermatozoa. A value <50% indicates abnormal motility—specifically, a condition in which progressively motile spermatozoa (grade a and grade b) constitute <50% of the total, or grade a (rapidly progressive) spermatozoa constitute <25%. Complete absence of sperm motility is termed necrozoospermia.
Sperm motility refers to the percentage of spermatozoa in semen exhibiting progressive (forward) movement.
Sperm motility is generally classified into four grades: Grade 0 (d-grade): immotile sperm—no movement; Grade I (c-grade): non-progressive movement—sperm move but not forward (e.g., in place or in circles); Grade II (b-grade): slow or sluggish forward movement; Grade III (a-grade): rapid, straight-line, progressive movement.
Normal reference values are as follows: ≥25% Grade III (a-grade) sperm, or the combined proportion of Grade III (a-grade) and Grade II (b-grade) sperm ≥50%.
For normal fertility, the proportion of motile sperm should exceed 70%. A value 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 routine seminal plasma analysis and detailed medical history evaluation to identify underlying causes—such as varicocele or genitourinary tract infection—and thereby determine the true etiology. Targeted treatment can then be initiated based on the identified cause.
