Table 1. Characteristics and summary of study results
References Country Study design Study subjects Sample size Stress exposure Questionnaire used for stress assessment Semen quality parameters analyzed WHO guideline edition Impaired semen quality parameters with psychological stress
Bártolo et al., 2016 Portugal Cross-sectional Infertile men 112 Infertility-related stress State Trait Anxiety Inventory SC, SPM, SAM 5º edition ↓ Slow progressive motility
Bhadoria et al., 2020 Índia Longitudinal Infertile men 50 Infertility-related stress Perceived Stress Scale SV, SC, SPM, SAM 5º edition None
Bhongade et al., 2015 India Cross-sectional Infertile men 70 Infertility-related stress Hospital Anxiety and Depression Score Questionnaire SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Sperm motility and↓ Normal sperm morphology
Bräuner et al., 2020 Denmark Cross-sectional Fertile and infertile men 423 Infertility-related stress Copenhagen Psychosocial Questionnaire; Stressful Life Events inventory SV, SC, TSC, SPM, SAM 5º edition None
Clarke et al., 1999 USA Longitudinal Infertile men 31 Infertility-related stress State Trait Anxiety Inventory SV, SC, TSC, SPM, SAM 1º edition ↓Sperm concentration and↓ Sperm motility
Collodel et al., 2008 Italy Longitudinal Infertile men 20 Infertility-related stress Psychological State of Stress Measure SV, SC, SPM 4º edition None
Eskiocak et al., 2005 Turkey Longitudinal Fertile men 27 Academic stress State Trait Anxiety Inventory SV, SC, SPM, SAM 3º edition ↓Sperm concentration,↓ Sperm motility
Eskiocak et al., 2005 Turkey Longitudinal Fertile men 34 Academic stress State Trait Anxiety Inventory SV, SC, SPM, SAM 3º edition ↓Sperm concentration,↓ Sperm motility,↑ Abnormal sperm morphology
Eskiocak et al., 2006 Turkey Longitudinal Fertile men 29 Academic stress State Trait Anxiety Inventory SV, SC, SPM, SAM 3º edition ↓Sperm concentration,↓ Sperm motility
Fenster et al., 1997 USA Cross-sectional Fertile men 164 Work-related stress and life events stress The Job Content Questionnaire; Stressful Life Events Inventory SV, SC, SPM 3º edition None
Giblin et al., 1988 USA Longitudinal Fertile men 28 Daily life stress and life events stress Van Atta’s Life Stress Questionnaire; Stressful Life Events Inventory SV, SC, TSC, SPM, SAM 1º edition ↓Volume and↓ Normal sperm morphology
Gollenberg et al., 2010 USA Cross-sectional Fertile men 744 Life events stress Stressful Life Events Inventory; Social Readjustment Rating Scale SV, SC, TSC, SPM, SAM 4º edition ↓Sperm concentration,↓ Sperm motility and↓ Total sperm count
Gözen et al., 2005 Turkey Longitudinal Fertile men 36 Academic stress State Trait Anxiety Inventory SV, SC, SPM, SAM 3º edition ↓Sperm concentration,↓ Sperm motility and↓ Normal sperm morphology
Gürhan et al., 2009 Turkey Longitudinal Fertile men 80 Infertility-related stress State Trait Anxiety Inventory; Beck Depression Inventory SV, SC, SPM, SAM 3º edition ↓ sperm motility
Hjollund et al., 2004a Denmark Longitudinal Fertile men 399 Work-related stress The job Content Questionnaire SV, SC, SAM 3º edition None
Hjollund et al., 2004b Denmark Longitudinal Fertile men 418 Daily life stress The General Health Questionnaire SV, SC, SAM 3º edition None
Janevic et al., 2014 USA Cross-sectional Fertile men 193 Work-related stress, life events and daily life stress The Job Content Questionnaire; Perceived Stress Scale; Stressful Life Events Inventory SV, SC, SPM, SAM 4º edition ↓Sperm concentration,↓ Sperm motility and↓ Total sperm count
Jurewicz et al., 2010 Polland Cross-sectional Fertile and infertile men 179 Work-related stress Subjective Work Characteristics Questionnaire SV, SC, SPM, SAM 4º edition ↓ Semen volume↓ Sperm motility
Jurewicz et al., 2014a Polland Cross-sectional Infertile men 336 Work-related stress Exposure to Occupational Factors Questionnaire SV, SC, SPM, SAM 5º edition ↓ Sperm motility
Jurewicz et al., 2014b Polland Cross-sectional Infertile men 327 Work-related stress and daily life stress Subjective Work Characteristics Questionnaire; Perceived Stress Scale SV, SC, SPM, SAM 4º edition None
Lund et al., 2023 Denmark Cross-sectional Infertile men 1,159 Infertility-related stress Perceived stress scale SV, SC, TSC 5º edition None
Nordkap et al., 2016 Denmark Cross-sectional Fertile men 1,215 Daily life stress The Copenhagen Psychosocial Questionnaire SV, SC, TSC, SPM, SAM 5º edition ↓Semen volume,↓Sperm concentration,↓ Total sperm count,↓ Normal sperm morphology
Nordkap et al., 2020 Denmark Cross-sectional Fertile men 1,362 Daily life stress and life events stress The Copenhagen Psychosocial Questionnaire; Stressful Life Events Inventory; Perceived Stress Scale SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Total sperm count,↓ Sperm motility
Nouri et al., 2014 Austria Longitudinal Infertile men 78 Infertility-related stress Fertility Problem Inventory Questionnaire SV, SC, TSC, SPM 3º edition None
Pan et al., 2022 China Cross-sectional Infertile men 378 Infertility-related stress Self-Administered 7-Item Generalized Anxiety Disorder (GAD-7) Scale SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Total sperm count,↓ Sperm motility
Pook et al., 1999 Germany Longitudinal Infertile men 158 Infertility-related stress Infertility Distress Scale SC, SPM, SAM 3º edition ↓Sperm concentration and↓ Sperm motility
Pook et al., 2004 Germany Longitudinal Infertile men 120 Infertility-related stress Infertility Distress Scale SC 4º edition ↓Sperm concentration
Shukla et al., 2010 India Longitudinal Fertile and infertile men 120 Infertility-related stress State Trait Anxiety Inventory SV, SC, TSC, SPM 4º edition ↓Sperm concentration and↓ Sperm motility
Singh et al., 2016 India Cross-sectional Infertile men 80 Infertility-related stress Hospital Anxiety and Depression Score questionnaire SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Sperm motility and↓ Normal sperm morphology
Vellani et al., 2013 Italy Cross-sectional Fertile and infertile men 179 Infertility-related stress State Trait Anxiety Inventory SV, SC, TSC, SPM, SAM 4º edition ↓Sperm volume,↓Sperm concentration,↓ Total sperm count, and↓ Sperm motility
Zorn et al., 2001 Slovenia Cross-sectional Infertile men 495 Infertility-related stress Zung's Anxiety Scale Inventory questionnaire SV, SC, TSC, SPM, SAM 4º edition ↓ Total sperm count, and↓ Sperm motility
Zorn et al., 2008 Slovenia Longitudinal Infertile men 1076 Infertility-related stress Zung's Anxiety Scale Inventory questionnaire SV, SC, SPM, SAM 4º edition None
Zou et al., 2018 China Cross-sectional Fertile men 637 Daily life stress Self-rating Depression Scale SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Total sperm count,
Zou et al., 2019 China Cross-sectional Fertile men 384 Work-related stress The job Content Questionnaire SV, SC, TSC, SPM, SAM 5º edition ↓Sperm concentration,↓ Total sperm count,

Abbreviations: total sperm count (TSP), sperm concentration (SC), sperm progressive motility (SPM), sperm abnormal morphology (SAM) and sperm vitality (SV); World Health Organization (WHO).