Vero cells stimulate human sperm motility in vitro.

Objective: To study human sperm motility in a coculture system for in vitro fertilization (IVF).
Design: We studied the viability and motility (percentage and curvilinear velocity) of human spermatozoa after incubation in: (1) medium 199 supplemented with fetal calf serum (M199/FCS) together with Vero cells; (2) Vero cell conditioned M199/FCS; (3) M199/FCS supplemented with Vero cell extract; and (4) some control media. In a second experiment, FCS was substituted by sera from different IVF patients.
Setting: Semen samples were obtained from the fertility laboratory of the St. Radbound Hospital, Nijmegen, The Netherlands.
Patients: Twelve men of couples with fertility problems.
Interventions: None.
Main Outcome Measure: The motility parameters were determined with a computerized motility-analyzing system, after 24 hours' incubation at 37 degrees C and 5% CO2. Viability was determined after eosin Y staining.
Results: Sperm viability was the same in all media. In the coincubation system, the Vero cell-conditioned medium, and the experiment with human sera, the sperm motility parameters were higher (P less than 0.005) than in the control media. Vero cell extract did not have this positive effect.
Conclusions: Coincubation has a positive effect on sperm motility and may be beneficial to IVF, intrauterine insemination, and artificial insemination.