The duration of infertility affects semen parameters in primary infertile men: results of a single-centre, cross-sectional study

Objective: To assess the relationship between the duration of infertility (DI) and the seminal parameters of a cohort of White-European primary infertile men. Patients and Methods: Data from 1644 infertile men were analysed. Patients were grouped according to the self-reported DI into 12-month time frames. Semen analysis values were assessed based on 2010 World Health Organisation reference criteria. Descriptive statistics tested the difference in clinical, hormonal and seminal parameters between groups. Logistic regression models assessed the impact of DI on semen parameters. Results: A DI of <12, 13–24, 25–36, 37–48, 49–60 and >60 months was found in 207 (12.6%), 651 (39.6%), 387 (23.5%), 168 (10.2%), 92 (5.6%) and 139 (8.4%) men, respectively. Patient's age (P < 0.001) and body mass index (P < 0.001) significantly increased along with DI. Hormonal values were similar across groups. Sperm concentration significantly decreased with DI (P = 0.01). Similarly, a higher rate of non-obstructive azoospermia (NOA) was more frequently found in men with a longer DI (P = 0.03). There were no differences in semen volume, sperm progressive motility, total motile sperm count (TMSC), and normal morphology across groups. Multivariable logistic regression analysis showed that DI was significantly associated with the risk of oligozoospermia (P < 0.001), TMSC <5 × 106 (P < 0.001), and NOA (P < 0.001). Conclusions: This cross-sectional study showed that DI had a negative impact on semen parameters in primary infertile men. Sperm concentration was negatively associated with DI and patients with a longer DI reported higher rates of azoospermia. Furthermore, DI was significantly associated with a higher risk of oligozoospermia, low TMSC, and NOA.