Objective: Fertilization capacity of capacitated sperm decreases

exponentially over time, but the reason is still under investigation.

The aim of the study was to analyze the effect of prolonged

incubation and temperature on sperm fertilization capacity with

motility and staining parameters of phospholipase C-zeta (PLCZ),

which is considered to be the oocyte activation factor.

Materials and Methods: Density gradient washing

was applied to semen of 11 infertile patients without severe

oligoasthenospermia out of 16 patients. The samples were divided

and cultured either at room temperature or at 37°C for 3 days. The

spermatozoons were evaluated for motility, PLCZ staining and

intensity daily.

Results: All parameters decreased both at room and body

temperature with increased incubation time. There was a strong

correlation between the change in motility and in the percentage

of PLCZ stained sperms, but this correlation decreased with

incubation time.

Conclusion: Prolonged incubation results show the correlation

between PLCZ staining parameters and motility. Routine use of

PLCZ staining together with semen analysis, will be useful to

predict fertilization capacity of the sperm especially for unexplained

infertility and fertilization failure cases, and also can increase the

success of assisted reproductive technologies (ART) cycles.