Temporal decline of semen quality amongst Saudi population in first two decades of 21st century

Background: Significant decline in the quality of semen has been reported in men living in Western countries. There is scarce evidence in middle eastern population and limited data from these countries was used in revised reference range values in the sixth edition of World Health Organization (WHO) manual for semen analysis. The objective of this study was to determine if semen quality has changed over time in Saudi Population in past 18 years (2004–2021). Methods: In this retrospective cohort, 9935 semen analysis reports were reviewed and temporal changes in semen parameters over 18 years were reported. Men who attended assisted reproductive technology Lab, King Faisal Specialist Hospital and Research Centre Jeddah, Kingdom of Saudi Arabia for semen analysis from 2004 to 2021 were included in this study. Results: Total sperm count (yearly slope = −3.63, 95% confidence interval (CI): −5.85 to −1.4, p = 0.003), motility (yearly slope −0.67, 95% CI: −0.86 to −0.47, p < 0.0001), morphology (yearly slope −0.51, 95% CI: −0.68 to −0.34, p < 0.0001), and semen volume (yearly slope −0.02, 95% CI: −0.036 to −0.009, p = 0.002) declined significantly from 2004 to 2021. The percentage of population with abnormal semen parameters, single/multiple sperm abnormalities including azoospermia (yearly slope 0.6, 95% CI: 0.16 to 1.0, p = 0.01), hypospermia (yearly slope 0.5, 95% CI: 0.23 to 0.78, p = 0.001), oligospermia (yearly slope 1.0, 95% CI: 0.67 to 1.46, p < 0.0001), asthenospermia (yearly slope 1.2, 95%CI: 0.92 to 1.55, p < 0.0001), teratospermia (yearly slope 3.1, 95% CI: 2.2 to 4.0, p < 0.0001) and oligoasthenoteratospermia (OAT) (yearly slope 1.4, 95% CI: 1.0 to 1.77, p < 0.0001) was significantly increased from 2004 to 2021. Conclusions: Significant decline in the semen parameters over the 18 years of study period suggest strong temporal relationship with quality of semen. The potential causes for such a significant regression in the semen characteristics were not explored in this study and warrant further research.