Abstract
Study question
Can health and lifestyle detrimental conditions impact the relationship between paternal age and semen quality parameters in a male population?
Summary answer
Health and lifestyle detrimental conditions can attenuate the negative relationship between age and sperm concentration in a male population.
What is known already
Paternal age has increased in parallel with maternal age but its contribution in couple subfertility deserves further investigation. Previous studies suggest that paternal ageing is associated with reduced semen volume and impaired sperm morphology and motility, but not with reduced sperm concentration. Several health and lifestyle conditions such as diabetes, hypertension and smoking can negatively affect semen quality. Since the distribution of these conditions is not homogeneous throughout men’s reproductive life, one can hypothesize that their presence may confound the association between paternal age and semen quality parameters in male populations.
Study design, size, duration
This is a retrospective study with data from 5565 men examined in a single fertility clinic between 2015 and 2020. The impact of health and lifestyle conditions was assessed by comparing the effects of age on semen parameters in two different patient populations: the overall patient population and a subpopulation excluding patients with detrimental health or lifestyle characteristics, both divided in 4 age groups (A: 25–34, B: 35–39, C: 40–44 and D: ≥45 years).
Participants/materials, setting, methods
The study includes 5565 men aged 24 to 72 years providing semen samples to assess volume, progressive motility and concentration (WHO) in a single fertility clinic. Patients presenting diabetes, heart/circulatory diseases, andrological disorders, genital neoplasms, cystic fibrosis, Y microdeletions, abusive alcohol intake, smoking and/or recreational use of drugs were excluded from the healthy subpopulation. The effect of age on semen parameters was assessed by ANOVA (motility and volume) or Kruskal-Wallis one-way ANOVA (concentration). Main results and the role of chance: Of 5565 men included in the study, 2150 (38.6%) did not present any of the detrimental health and lifestyle conditions described above. In the overall patient population, semen volume [Mean±SD (mL); A: 3.14 ± 1.55, B: 3.01 ± 1.53, C: 2.83 ± 1.52, D: 2.65 ± 1.58; p < 0.001] and sperm progressive motility [Mean±SD (%); A: 33.1 ± 18.0, B: 31.7 ± 17.7, C: 31.4 ± 17.5, D: 28.4 ± 17.5; p < 0.001] gradually and significantly decreased with paternal age. The same effect was observed in the patient subpopulation excluding detrimental health and lifestyle conditions [(mL; A: 3.21 ± 1.58, B: 3.05 ± 1.51, C: 2.89 ± 1.59, D: 2.78 ± 1.50; p < 0.001); (%; A: 35.85 ± 17.4, B: 33.7 ± 17.4, C: 32.2 ± 17.1, D: 30.3 ± 16.5; p < 0.001)]. However, sperm concentration significantly decreased with paternal age in the subpopulation excluding detrimental health and lifestyle conditions [(Mean±SD) million/mL; A: 43.19 ± 41.0, B: 38.8 ± 38.6, C: 38.4 ± 34.6, D: 36.6 ± 33.9; p < 0.001], but not in the overall population (million/mL; A: 38.17 ± 40.9, B: 36.7 ± 34.7, C: 35.3 ± 35.1, D: 35. 1± 37.5; p = 0.088).
Limitations, reasons for caution
This study is limited by its retrospective nature and by the accuracy of data on health and lifestyle conditions provided by the patients. Differences between age groups not controlled for in the study could also impact the results.
Wider implications of the findings: Ours findings suggest that health and lifestyle conditions may confound the effects of age on semen and sperm quality. Therefore, these data constitute a useful reference for the accurate assessment of the impact of male age on fertility.
Trial registration number
Not applicable
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