According to existing studies, sedentary behavior contributes to male infertility. Both preclinical and clinical studies have investigated the association between physical exercise, semen quality, and pregnancy rates with heterogeneous results. The current review sought to examine the relationship between physical activity (PA) and male infertility, semen characteristics, and pregnancy rates. Pre-clinical studies demonstrated mixed benefits from exercise, with diet being an important consideration. Some forms of PA showed an improvement in pregnancy rates, while others did not consistently improve semen quality. Data also suggests that more intense exercise and certain types of exercise may impair male fertility. Given the limited number of randomized trials, future research is required to examine the relationship between specific forms of exercise and semen parameters along with reproductive outcomes.

Since the beginning of the coronavirus disease 19 (COVID-19) pandemic, efforts in defining risk factors and associations between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), clinical, and molecular features have initiated. After three years of pandemic, it became evident that men have higher risk of adverse outcomes. Such evidence provided the impetus for defining the biological fundaments of such a gender disparity. Our objective was to analyze the most recent literature with the aim of defining the relationship between COVID-19 and fertility, in particular, we assessed the interplay between SARSCoV-2 and testosterone in a systematic review of literature from December 2019 (first evidence of a novel coronavirus in the Hubei province) until March 2022. As a fundamental basis for understanding, articles pertaining preclinical aspects explaining the gender disparity (n=9) were included. The main review categories analyzed the risk of being infected with SARS-CoV-2 according to testosterone levels (n=5), the impact of serum testosterone on outcomes of COVID-19 (n=23), and the impact SARSCoV-2 on testosterone levels after infection (n=19). Preclinical studies mainly evaluated the relation between angiotensinconverting enzyme 2 (ACE2) and its androgen-mediated regulation, articles exploring the risk of COVID-19 according to testosterone levels were few. Although most publications evaluating the effect of COVID-19 on fertility found low testosterone levels after the infection, follow-up was short, with some also suggesting no alterations during recovery. More conclusive findings were observed in men with low testosterone levels, that were generally at higher risk of experiencing worse outcomes (i.e., admission to intensive care units, longer hospitalization, and death). Interestingly, an inverse relationship was observed in women, where higher levels of testosterone were associated to worse outcomes. Our finding may provide meaningful insights to better patient counselling and individualization of care pathways in men with testosterone levels suggesting hypogonadism.

Purpose: Medicinal and recreational cannabis use has grown exponentially, however, its effect on testicular function and spermatogenesis remains uncertain. The aim of this study was to evaluate the association between cannabis use and semen parameters in a cohort of Asian-American men with unknown fertility. Materials and Methods: Asian men were recruited to complete an online survey and submit a semen sample. Semen analysis, demographic data, lifestyle factors, and cannabis use habits were collected. Linear and logistic regression analyses were used to determine. Results: Among the 112 men included in this study, 51 used cannabis at least once in their lifetime, 30 men used cannabis at least once in the last 12 months, and 26 men used cannabis at least once in the last 30 days. Adjusted linear regression analyses identified an association between cannabis use in the previous 30 days and worse sperm morphology (β: -0.45, p=0.025) and sperm motility (β: -1.64, p=0.016). However, when stratifying by subfertile semen quality (i.e., WHO criteria), no association was identified between semen quality and cannabis use. Lower sperm morphology and motility are partially associated with recent cannabis use, while all other semen parameters are not. Conclusions We did not observe any consistent associations between cannabis use on any semen parameters in Asian-American men. Further studies within the field are needed to explore racial and ethnic differences in semen quality and lifestyle factors.

Purpose: Normative male genital measurements are clinically useful and temporal changes would have important implications. The aim of the present study is to characterize the trend of worldwide penile length over time. Materials and Methods: A systematic review and meta-analysis using papers from PubMed, Embase, and Cochrane Library from inception to April 2022 was performed. PRISMA guidelines were used for abstracting data and assessing data quality and validity. Pooled means and standard deviations for flaccid, stretched, and erect length were obtained. Subgroup analyses were performed by looking at differences in the region of origin, population type, and the decade of publication. Metaregression analyses were to adjusted for potential confounders. Results: Seventy-five studies published between 1942 and 2021 were evaluated including data from 55,761 men. The pooled mean length estimates were flaccid length: 8.70 cm (95% CI, 8.16–9.23), stretched length: 12.93 cm (95% CI, 12.48–13.39), and erect length: 13.93 cm (95% CI, 13.20–14.65). All measurements showed variation by geographic region. Erect length increased significantly over time (QM=4.49, df=2, p=0.04) in several regions of the world and across all age groups, while no trends were identified in other penile size measurements. After adjusting for geographic region, subject age, and subject population; erect penile length increased 24% over the past 29 years. Conclusions The average erect penis length has increased over the past three decades across the world. Given the significant implications, attention to potential causes should be investigated.

Purpose: To assess the relationship between clinical and semen characteristics and assisted reproductive technology (ART) outcomes with different birth weight (BW) categories in a cohort of infertile men. Materials and Methods: Data from 1,063 infertile men were analyzed. Patients with BW ≤2,500, 2,500–4,000, and ≥4,000 g were considered as having low BW (LBW), normal BW (NBW), and high BW (HBW), respectively. Testicular volume (TV) was assessed with a Prader orchidometer. Serum hormones were measured in all cases. Semen analyses were categorized based on 2021 World Health Organization reference criteria. Sperm DNA fragmentation (SDF) was tested in every patient and considered pathological for SDF >30%. ART outcomes were available for 282 (26.5%) patients. Descriptive statistics and logistic regression analyses detailed the association between semen parameters and clinical characteristics and the defined BW categories. Results: Of all, LBW, NBW, and HBW categories were found in 79 (7.5%), 807 (76.0%), and 177 (16.5%) men, respectively. LBW men had smaller TV, presented higher follicle-stimulating hormone (FSH) but lower total testosterone levels compared to other groups (all p<0.01). Sperm progressive motility (p=0.01) and normal morphology (p<0.01) were lower and SDF values were higher (all p<0.01) in LBW compared to other groups. ART pregnancy outcomes were lower in LBW compared to both NBW and HBW categories (26.1% vs. 34.5% vs. 34.5%, p=0.01). At multivariable logistic regression analysis, LBW was associated with SDF >30% (odd ratio [OR] 3.7; p<0.001), after accounting for age, Charlson Comorbidity Index (CCI), FSH, and TV. Similarly, LBW (OR 2.2; p<0.001), SDF >30% (OR 2.9; p<0.001) and partner’s age (OR 1.3; p=0.001) were associated with negative ART outcomes, after accounting for the same predictors. Conclusions LBW was associated with impaired clinical and semen characteristics in infertile men compared to both NBW and HBW. SDF and ART outcomes were significantly worse in the LBW group.

Purpose: In industrialized countries, air pollutants levels have been monitored closely for environmental and research issues. Using Italian data, we aimed to investigate the association between air pollutants levels and semen parameters in a cohort of non-Finnish white-European men presenting for couple’s infertility. Materials and Methods: Complete demographic and laboratory data from 1,152 infertile men consecutively assessed between January 2015 and January 2018 were analyzed. Semen analyses were based on the 2010 World Health Organization reference criteria. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). We analyzed the annual average level of the three main markers of air pollution (Pm10, Pm2.5, and NO2) between 2014 and 2018. Descriptive statistics, linear and logistic regression analyses tested the association between air pollutants levels and semen parameters. Results: Of 1,152 men, 87 (7.55%) had normal sperm parameters at first semen analysis. Of 1,065 patients with abnormal semen analyses, 237 (22.25%), 324 (30.42%), and 287 (26.95%) patients presented 1, 2 or 3 abnormalities, respectively, and 217 (20.38%) were azoospermic. At linear regression analysis, Pm10, Pm2.5, and NO2 were negatively associated with sperm morphology (Pm10: β=-0.5288 µg/m3, p=0.001; Pm2.5: β=-0.5240 µg/m3, p=0.019; NO2: β=-0.4396 µg/m3, p<0.0001). Furthermore, the adjusted odds of normal sperm morphology <4% were 1.06 (95% confidence interval [CI], 1.03–1.09; p=0.007) for Pm10, 1.07 (95% CI, 1.03–1.11; p=0.007) for Pm 2.5, and 1.03 (95% CI, 1.02–1.05; p=0.001) for NO2, respectively. Conclusions In a large homogenous cohort of infertile men, Pm10, Pm 2.5, and NO2 levels were negatively associated with sperm morphology. Conversely, no clear association was observed with other macroscopic sperm parameters.

Purpose: Overall, male factor infertility (MFI) accounts for up to 50% of etiologies of couple’s infertility, with almost 30% of MFI cases being idiopathic in nature. Idiopathic MFI does not support a tailored treatment work-up in clinical practice. To investigate rates of and characteristics of men presenting for idiopathic versus unexplained primary infertility as compared with same-ethnicity, age-comparable fertile men. Materials and Methods: Demographic, clinical and laboratory data from 3,098 primary infertile men consecutively evaluated were analyzed and compared with those of 103 fertile controls. Idiopathic male infertility (IMI) was defined for abnormality at semen analysis with no previous history of diseases affecting fertility and normal findings on physical examination and genetic and laboratory testing. Unexplained male infertility (UMI) was defined as infertility of unknown origin with completely normal findings at semen analysis. Descriptive statistics and logistic regression models tested the association between clinical variables and idiopathic infertility status. Results: Overall, 570 (18.5%) and 154 (5.0%) patients depicted criteria suggestive for either IMI or UMI, respectively. Groups were similar in terms of age, BMI, CCI, recreational habits, hormonal milieu, and sperm DNA fragmentation indexes. Conversely, testicular volume was lower in IMI (p<0.001). Vitamin D3 levels were lower in IMI vs. UMI vs. fertile controls (p=0.01). At multivariable logistic regression analysis only vitamin D3 deficiency (OR, 9.67; p=0.03) was associated with IMI. Characteristics suggestive for IMI versus UMI were observed in almost 20% and 5% of men, respectively. Overall, clinical differences between groups were slightly significant and certainly not supportive of a tailored management work-up. Conclusions Current findings further support the urgent need of a more detailed and comprehensive assessment of infertile men to better tailoring their management work-up in the everyday clinical setting.

Substances of abuse (SoA), as well as smoking and alcohol consumption, are well known for their impact on male fertility status, erectile function, and ejaculation. We assessed SoA consumption habits in a cohort of men seeking medical attention for uro-andrological purposes. Data from 7447 men seeking medical attention for the first time for uro-andrological purposes were analyzed. A complete medical and sexual history was collected for each patient. Smoking, alcohol, and SoA consumption were investigated. Descriptive statistics was used to describe the whole cohort. The primary motivations for their evaluation were lower urinary tract symptoms (LUTS), erectile dysfunction (ED), and infertility in 1912 (25.7%), 2944 (39.5%), and 2591 (34.8%) men, respectively. Previous use of SoA was reported by 378 (5.1%) men, and 190 (2.6%) individuals were current users. Patients seeking medical attention for infertility were more frequently current SoA users (107; 4.1%) than men with ED (66; 2.2%) and LUTS (17; 0.9%) (both P < 0.001). Current users of SoA were younger than those with past or no SoA history (P < 0.001). Current SoA users were more frequently smokers (P < 0.001) and alcohol consumers (P < 0.001) than those with a previous history or those who had never tried SoA. In conclusion, approximately 3% of men seeking medical attention for uro-andrological purposes were current SoA consumers. Infertile men reported a higher use of SoA than those with ED or LUTS. Current SoA users were younger and more frequently concomitant smokers and alcohol consumers compared to those who did or had never used SoA.

Testicular volume (TV) is considered a good clinical marker of hormonal and spermatogenic function. Accurate reference values for TV measures in infertile and fertile men are lacking. We aimed to assess references values for TV in white-European infertile men and fertile controls. We analyzed clinical and laboratory data from 1940 (95.0%) infertile men and 102 (5.0%) fertile controls. Groups were matched by age using propensity score weighting. TV was assessed using a Prader orchidometer (PO). Circulating hormones and semen parameters were investigated in every male. Descriptive statistics, Spearman's correlation, and logistic regression models tested potential associations between PO-estimated TV values and clinical variables. Receiver operating characteristic (ROC) curves were used to find TV value cutoffs for oligoasthenoteratozoospermia (OAT) and nonobstructive azoospermia (NOA) status in infertile men. The median testicular volume was smaller in infertile than that of fertile men (15.0 ml vs 22.5 ml; P < 0.001). TV positively correlated with total testosterone, sperm concentration, and progressive sperm motility (all P ≤ 0.001) in infertile men. At multivariable logistic regression analysis, infertile status (P < 0.001) and the presence of left varicocele (P < 0.001) were associated with TV < 15 ml. Testicular volume thresholds of 15 ml and 12 ml had a good predictive ability for detecting OAT and NOA status, respectively. In conclusion, infertile men have smaller testicular volume than fertile controls. TV positively correlated with total testosterone, sperm concentration, and progressive motility in infertile men, which was not the case in the age-matched fertile counterparts.