Semen parameters are seriously affected in acephalic spermatozoa syndrome.

Background: Previous studies have reported that some patients with headless spermatozoa have poor semen quality, but there has been no published systematic analysis of semen quality in patients with different proportions of headless spermatozoa in semen. We aimed to explore the association of acephalic spermatozoa syndrome and semen quality in men with distinct proportions of headless spermatozoa.

Material And Methods: Semen parameter values in patients for whom headless spermatozoa were found in the ejaculates was studied and compared to that of 413 age-matched prenatal examination patients. All semen samples were analyzed following the same methodology in a single laboratory.

Results: All semen parameter values except semen volume were negatively (P < 0.05) correlated with the proportion of headless spermatozoa. The semen samples were divided into four groups on the basis of the proportion of headless spermatozoa (PHS) as follows: 0 < PHS ≤ 5% (n = 172, Group A1); 5 < PHS ≤ 10% (n = 76, Group A2); 10 < PHS ≤ 20% (n = 71, Group B); and PHS > 20% (n = 71, Group C). In Group A1, only one semen parameter value (progressive motility) was lower than those of the control group, but in Group A2, this increased to five (sperm vitality, normal sperm morphology, sperm motility, VCL (curvilinear velocity) and ALH (amplitude of lateral head displacement)). Worse still, all semen parameter values were significantly lower in Group B and Group C than in the control group (P < 0.05).

Conclusions: Semen samples containing headless spermatozoa tend to have lower quality than samples without headless spermatozoa. Increases in the proportion of headless spermatozoa in semen are associated with decreased semen quality. We suggest that headless spermatozoa should be seriously assessed and accurately counted in semen analysis, especially for ejaculate in which the proportion of headless spermatozoa exceeds 5%.