Background: The data on the association between the abstinence period and sperm motility are conflicting.
Methods: Ejaculates from 422 men assessed for infertility were analysed according to the World Health Organization (WHO) guidelines. Seminal plasma neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc and fructose were measured. Three groups were defined according to the length of sexual abstinence: G2-3 (2-3 days), G4-5 (4-5 days) and G6-7 (6-7 days).
Results: The total percentage of progressively motile spermatozoa was significantly higher in G4-5 compared with G2-3 and G6-7 (medians 55 versus 47 and 42%; P=0.039 and P <0.001, respectively). The percentage of spermatozoa with tail defects was significantly higher in G6-7 compared with G2-3 and G4-5 (medians 14 versus 10 and 10%; P=0.011 and P=0.002, respectively). NAG was significantly lower in G2-3 compared with G4-5 and G6-7 (medians 23 versus 34 and 34 mU/ejaculate; P <0.001 and P=0.001, respectively). The same trend was found regarding zinc (medians 6 versus 8 and 8 mumol/ejaculate; P=0.001 and P=0.005, respectively).
Conclusions: Within the time interval recommended by the WHO (2-7 days), the length of the abstinence period is associated with sperm characteristics and should be taken into consideration when interpreting results of semen analysis.