Laptop and tablet use and their influence on total motile sperm count parameters: are laptops linked to infertility in Jamaican men?

Infertility is defined as the inability to conceive after one year of unprotected intercourse. It is estimated that 20% of couples of reproductive age worldwide are affected by infertility, half of whom are affected by male infertility. Wi-Fi has become ubiquitous and is used in a wide range of devices. These devices emit signals that are absorbed by the human body and are thought to have harmful effects on the male reproductive system. Compared to other commonly used wireless devices, laptops and tablets are used closer to the male reproductive system. The authors investigated the association between total motile sperm count (TMSC), a good predictor of male fertility, and laptop and tablet use in Jamaican men who underwent infertility evaluation.

A total of 156 participants provided written informed consent and were included in the study. Men with a self-reported medical history of conditions known to affect sperm quality were excluded from the study. These conditions included previous diagnoses of mumps, undescended testicles, varicocele/varicocele repair, and certain diagnosed sexually transmitted diseases. Data were collected between February 2020 and July 2021. The 25-item wireless device use questionnaire, was designed by the principal investigators (an embryologist and a wireless communication engineer) to capture the frequency of laptop and tablet use. Semen analyses were performed according to the guidelines established by the World Health Organization. Semen analyses were performed without prior knowledge of wireless device use. The primary independent variable of interest was a measurable indicator of the frequency of laptop and tablet use. Laptop and tablet use were both categorized into three groups: low use (< 2 h/day), medium use (2–5 h/day), and high use (> 5 h/day). Other independent variables included in the statistical analyses were age, duration of attempts to become pregnant, previous pregnancies, and recreational drug use. Unadjusted and adjusted analyses of total motile sperm count (TMSC) and associated parameters (semen volume, sperm count, and sperm motility) were performed for indices of laptop and tablet use and previously selected confounders. All analyses were performed using SPSS.

Of the 156 participants who gave consent, 68% were younger than 40 years old. Their ages ranged from 22 to 60 years old (mean = 37.21, standard deviation = 7.27). Most subjects were of normal weight and consumed alcohol; only a few reported using drugs in their free time. Laptop and tablet users accounted for 64% (n = 100) and 36% (n = 57) of participants, respectively. Most participants reported using their laptops and tablets at a desk (73% and 78%, respectively). Participants who reported high laptop use were more likely to have been trying to conceive for one or more years and were more likely to be younger (< 40 years).

The only statistically significant difference was between participants with normal versus abnormal semen volume and those who reported 2 hours or more of laptop use per day, which corresponds to medium and high use. The only semen parameter associated with device use was volume. Unadjusted logistic regression analyses showed that medium laptop use was approximately 16 times more likely to result in low semen volume than non-use (p = 0.004). A significant correlation was also found between high laptop use and TMSC score (p = 0.052). The observation that laptop use is related to low semen volume, a TMSC parameter, is of great clinical significance.

The study found that frequent laptop use was associated with decreased semen volume in men seeking fertility evaluation. Users who spent 2 to 5 hours per day on their laptops were approximately 16 times more likely to be diagnosed with low semen volume. Although both laptops and tablets emit radiofrequency electromagnetic radiation (RF-EMR), the relative size and proximity of their Wi-Fi antennas to organs and tissues may lead to different distributions and absorptions of RF-EMR. Tablets are typically held farther away from the lap and reproductive organs than laptops, which may result in less RF-EMR exposure to the testes. This difference in positioning may explain why the effects of tablet use on TMSC are less significant.

Future studies are needed to determine what constitutes "safe" distances for operating wireless devices and to distinguish between RF-EMR-specific thermal and non-thermal effects on sperm parameters. However, since most participants reported using their laptops on a desk rather than on their lap, the likelihood of non-thermal RF-EMR exposure is (significantly) greater than that of thermal effects. The finding that increased laptop use correlates with a reduction in semen volume is concerning.

Secretions from the seminal vesicles and prostate account for approximately 90% of semen volume. Animal studies have shown significant pathological changes in the seminal vesicles after exposure to Wi-Fi radiation. Although the association between increased laptop use and TMSC was only nearly significant, it may have reached significance with a larger sample size. Several reports show that African-Caribbean men, particularly Jamaican men, respond differently to certain external factors. This results in an unusually high incidence of prostate cancer compared to the global rate. Overall, these findings underscore the need for further culturally relevant studies. Of particular concern is the finding of an association between increased laptop use and longer times to conceive.

The authors suggest adding screening for wireless device use to the standard procedure when screening men for infertility. In particular, men in the medium and high use groups should be advised to take protective measures to minimize the risk of excessive EMR exposure from these devices. Some limitations of the study design should be noted. The results may not be generalizable to the entire male population because the study focused exclusively on Jamaican men undergoing infertility screening. In addition, RF-EMR emissions were estimated based on the participants' reported level of use rather than measured during the analysis. (AT)