Cervical mucins affect the motility of human spermatozoa in vitro

Abstract

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

Setting: University hospital.

Patient(s): Healthy donors.

Intervention(s): 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.

Main outcome measure(s): 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.

Result(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%.

Conclusion(s): Cervical mucins increase the percentage of progressively motile sperm and decrease the percentage of sperm that show hyperactivation.