Cervical mucins affect the motility of human spermatozoa in vitro

To test the hypothesis that human cervical mucins affect the motility and hyperactivated motility of human spermatozoa.

University hospital.

Healthy donors.

Swim-up sperm fractions of normozoospermic semen samples were incubated in the presence of 0 (control) to 1.3 mg/mL of mucins purified from cervical mucus plugs released during labor. Motility analyses were performed at time 0, and after 0.5, 1, 3, and 7 hours.

Sperm kinematic variables recorded by computer-aided sperm analysis. Hyperactivation was defined as linearity <30%, amplitude of lateral head displacement >7.0 microm, and curvilinear velocity >70 microm/s.

A dose-related effect of cervical mucins on sperm motility was found. Mucins at a concentration of 1.3 mg/mL caused an immediate and significant increase in sperm linearity (27%) and straight-line velocity (16%) compared with control samples. During the first 3 hours of incubation, an approximately 25% increase in linearity and straight-line velocity was found; this increase was statistically significant. Effects on the hyperactivation pattern were found as incubation with mucins for 3 and 7 hours significantly reduced the percentage of hyperactivation from 18% to 9%.

Cervical mucins increase the percentage of progressively motile sperm and decrease the percentage of sperm that show hyperactivation.