Association between self-reported mobile phone use and the semen quality of young men

Abstract

Association between self-reported mobile phone use and the semen quality of young men Rita Rahban, Alfred Senn, Serge Nef, Martin Rӧӧsli. Association between self-reported mobile phone use and the semen quality of young men. Fertility and Sterility, 2023, doi: 10.1016/j.fertnstert.2023.09.009. Abstract Objectives To investigate the association between mobile phone exposure and semen parameters. Design A nationwide cross-sectional study. Setting Andrology laboratories in close proximity to 6 army recruitment centers. Patients In total, 2886 men from the general Swiss population, 18–22 years old, were recruited between 2005 and 2018 during military conscription. Intervention Participants delivered a semen sample and completed a questionnaire on health and lifestyle, including the number of hours they spent using their mobile phones and where they placed them when not in use. Main Outcome Measures Using logistic and multiple linear regression models, adjusted odds ratios and β coefficients were determined, respectively. The association between mobile phone exposure and semen parameters such as volume, sperm concentration, total sperm count (TSC), motility, and morphology was then evaluated. Results A total of 2759 men answered the question concerning their mobile phone use, and 2764 gave details on the position of their mobile phone when not in use. In the adjusted linear model, a higher frequency of mobile phone use (>20 times per day) was associated with a lower sperm concentration (adjusted β: −0.152; 95% confidence interval: −0.316; 0.011) and a lower TSC (adjusted β: −0.271; 95% confidence interval: −0.515; −0.027). In the adjusted logistic regression model, this translates to a 30% and 21% increased risk for sperm concentration and TSC to be below the World Health Organization reference values for fertile men, respectively. This inverse association was found to be more pronounced in the first study period (2005–2007) and gradually decreased with time (2008–2011 and 2012–2018). No consistent associations were observed between mobile phone use and sperm motility or sperm morphology. Keeping a mobile phone in the pants pocket was not found to be associated with lower semen parameters. Conclusion This large population-based study suggests that higher mobile phone use is associated with lower sperm concentration and TSC. The observed time trend of decreasing association is in line with the transition to new technologies and the corresponding decrease in mobile phone output power. Prospective studies with improved exposure assessment are needed to confirm whether the observed associations are causal. Excerpts ... The energy absorbed by the body depends mainly on the transmission duration, the source’s strength, and the distance to the source. The specific absorption rate decreases with the square of the distance to the source, although the situation can be much more complex close to the source. In addition to potential inaccuracies in reporting hours per day of mobile phone use, radiofrequency exposure depends on characteristics that were not collected, such as brand and generation of the mobile phone, applications on the phone, network quality, distance to base stations, and use of earpieces and protective covers (46, 47). With technical development, the output power of mobile phones has decreased as 3G phones emit, on average, 100–500 times lower levels than 2G phones. In contrast, modern smartphones are much more active in standby mode compared with previous bar phones (48). Therefore, the number of applications on the phone and whether the person is stationary or not may play an important role. During traveling, for example, mobile phones are connecting more frequently and with higher output power on average (49). Such limitations, together with random errors in self-reported use, cause nondifferential exposure misclassification, which would attenuate our estimates and should be considered when interpreting the data.... Conclusion The lack of clear evidence for a negative association between mobile phone use and male fertility, as well as the dramatic increase in cell phone use over the past decade, underscores the need for further research in this area. From this perspective, it is important to conduct prospective observational studies with men from the general population and to accurately measure the RF-EMF exposure to the testicles and the hypothalamic-pituitary- gonadal axis. This would allow us to examine the association between cell phone use, RF-EMF exposure, and semen quality and to better understand the mode of action of RF-EMF on the male reproductive system. Open access paper: fertstert.org

AI evidence extraction

Main findings

In adjusted linear models, higher self-reported mobile phone use (>20 times/day) was associated with lower sperm concentration (adjusted β −0.152; 95% CI −0.316 to 0.011) and lower total sperm count (adjusted β −0.271; 95% CI −0.515 to −0.027). In adjusted logistic models, this corresponded to a 30% increased risk of sperm concentration and a 21% increased risk of TSC being below WHO reference values. Associations were more pronounced in 2005–2007 and decreased over later periods; no consistent associations were observed for motility or morphology, and keeping the phone in the pants pocket was not associated with lower semen parameters.

Outcomes measured

• semen volume
• sperm concentration
• total sperm count (TSC)
• sperm motility
• sperm morphology
• risk of sperm concentration below WHO reference values
• risk of TSC below WHO reference values

Limitations

• Cross-sectional design (cannot establish causality)
• Exposure based on self-reported phone use and carrying position; potential reporting inaccuracies
• Likely nondifferential exposure misclassification; RF exposure determinants not collected (e.g., phone brand/generation, apps, network quality, distance to base stations, earpiece use, protective covers)
• Exposure not directly measured at the testicles or along the hypothalamic-pituitary-gonadal axis

Suggested hubs

• mobile-phones (0.95)
  Study evaluates self-reported mobile phone use in relation to semen parameters.

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        "duration": "self-reported mobile phone use (e.g., >20 times/day; hours spent using phone) and phone carrying position when not in use"
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    "population": "Men from the general Swiss population aged 18–22 years recruited during military conscription (2005–2018)",
    "sample_size": 2886,
    "outcomes": [
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    "main_findings": "In adjusted linear models, higher self-reported mobile phone use (>20 times/day) was associated with lower sperm concentration (adjusted β −0.152; 95% CI −0.316 to 0.011) and lower total sperm count (adjusted β −0.271; 95% CI −0.515 to −0.027). In adjusted logistic models, this corresponded to a 30% increased risk of sperm concentration and a 21% increased risk of TSC being below WHO reference values. Associations were more pronounced in 2005–2007 and decreased over later periods; no consistent associations were observed for motility or morphology, and keeping the phone in the pants pocket was not associated with lower semen parameters.",
    "effect_direction": "mixed",
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        "Exposure based on self-reported phone use and carrying position; potential reporting inaccuracies",
        "Likely nondifferential exposure misclassification; RF exposure determinants not collected (e.g., phone brand/generation, apps, network quality, distance to base stations, earpiece use, protective covers)",
        "Exposure not directly measured at the testicles or along the hypothalamic-pituitary-gonadal axis"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
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