Duration of sexual abstinence: epididymal and accessory sex gland secretions and their relationship to sperm motility.

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.