Physical activity, fatness, educational level and snuff consumption as determinants of semen quality: findings of the ActiART study

Impact of physical activity on semen quality: a review of current evidence

A growing global trend indicates a decline in semen quality, with a lack of physical activity identified as one of the contributing factors. Exercise is medication, and numerous studies have explored its effects on semen quality. However, there is no consensus on the most effective type and intensity of exercise for improving semen quality, owing to inconsistent findings across studies. These discrepancies may be attributable to variations in study populations (e.g., healthy versus infertile individuals) and research methodologies (e.g., observational versus interventional studies). This paper reviews the existing literature from the databases PubMed, Web of Science, and Google Scholar, reclassifying articles on their subject and research designs to delineate the relationship between exercise and semen quality. It also summarizes the mechanisms through which exercise influences semen quality, including hormonal regulation, oxidative stress, and inflammatory factors.

Intensity and type of physical activity and semen quality in healthy young men

OBJECTIVE

To study the relationship between intensity of physical activity (PA) and semen quality in healthy young men.

DESIGN

A prospective cohort study with repeated measures for each subject.

PATIENT(S)

Healthy high school and university students who did not regularly smoke tobacco, drink alcohol, or take drugs or medicine, with normal body mass index and abdominal circumference.

EXPOSURE

The participants underwent urologic visit, fasting blood and semen sampling, and anthropometric measurements, and filled in the International Physical Activity Questionnaire, at enrollment and after 4 and 8 months. Duration and frequency of walking, moderate-intensity, and vigorous-intensity activities in the last week were assessed, and a score was computed for total PA.

MAIN OUTCOME MEASURE(S)

Semen specimens were taken at each visit through masturbation, after 3-5 days of abstinence, and analyzed by an expert urologist. Sperm concentration, total and progressive motility, and proportion of spermatozoa with normal morphology were measured. Linear and generalized linear mixed models with the Poisson family were fitted to assess the relationships between PA variables and sperm parameters, after adjusting for season, time, and study arm. The shape of the relationship was modeled through restricted cubic spline regression.

RESULT(S)

A total of 143 male subjects, aged 18-23 years (median, 20 years), were enrolled. They had a median PA of 1,960 (95% confidence interval, 1,055-3,182) Metabolic Equivalent of Tasks in min/wk. Statistically significant differences were found for total, progressive motility, and percent of cell with normal morphology across categories of total PA; the highest medians of total (47%) and progressive motility (34%) and of the percentage of normal morphology cells (7%) were found for medium PA. Positive associations of sperm total motility and normal morphology with medium levels of PA, and negative associations with walking and vigorous-intensity activity emerged. Spline regression analysis confirmed these findings, showing an inverse U-shape relationship, with the highest value of total motility and normal morphology for medium PA, and the lowest values for lower and higher activity.

CONCLUSION(S)

These findings support the present recommendations to practice moderate PA for health improvement, including semen quality.

The sitting men: A systematic review of spare and working time exposure to sedentariness in relation to semen parameters

BACKGROUND

Over the past few decades, several studies have found that semen quality parameters have steadily declined over time. Many hypotheses have been made to explain this finding, among which a sedentary lifestyle has been investigated. To synthesize the current evidence, we performed a systematic review of published papers reporting on the relationship between sedentary habits and semen parameters.

METHODS

Embase and PubMed were systematically searched for papers published in English up to May 2023. We included all full-text observational papers that reported the relationship between sedentariness and semen parameters. Article selection adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

Sixteen observational studies were ultimately included, six in healthy men and ten in men from Fertility Clinics. They encompassed a total of 13,509 men, with 9877 being healthy men and 3632 presenting at Fertility Clinics for initial assessment. In terms of semen volume, no association emerged in the six studies involving healthy men: however, results in men referring to fertility clinics mainly showed no association, with one indicating a decline and one higher volume. Twelve studies did not report differences in sperm concentration, while one study in men from Fertility Clinics and two in healthy men observed a decline in this parameter with increasing time spent on TV watching or sedentary posture in spare time. Total sperm count was found to be similar across groups of inactivity, except for one study that showed a significant decrease when men from Fertility Clinics spent more time watching TV. No significant differences were reported in sperm motility across all studies, with only one study, among those addressing sperm morphology, indicating a lower percentage of normal forms in men watching TV more than 3 h per day. Finally, three studies conducted in men referring to Fertility Clinics analyzed the sperm DNA fragmentation index. Two of these studies found a higher DNA fragmentation index in men spending more time per day in a sitting posture.

CONCLUSIONS

This review suggests a weak association between time spent sitting during spare time and sperm concentration, but the findings are inconsistent, highlighting the need for further research.

Cr (VI)-induced ribosomal DNA copy number variation is associated with semen quality impairment: Evidence from human to animal study

OBJECTIVES

This study aimed to analyze the possible role of rDNA copy number variation in the association between hexavalent chromium [Cr (VI)] exposure and semen quality in semen donors and further confirm this association in mice.

METHODS

In this cross-sectional study, whole blood and semen samples were collected from 155 semen donors in the Zhejiang Human Sperm Bank from January 1st to April 31st, 2021. Adult C57BL/6 J male mice were treated with different doses of Cr (VI) (0, 10, or 15 mg/kg b.w./day). Semen quality, including semen volume, total spermatozoa count, sperm concentration, progressive motility, and total motility, were analyzed according to the WHO laboratory manual. Cr concentration was detected using inductively coupled plasma mass spectrometry. The rDNA copy number was measured using qPCR.

RESULTS

In semen donors, whole blood Cr concentration was negatively associated with semen concentration and total sperm counts. Semen 5 S and 45 S rDNA copy numbers were negatively associated with whole blood Cr concentration and whole blood 5.8 S rDNA copy number was negatively associated with semen Cr concentration. In mice, Cr (VI) damaged testicular tissue, decreased semen quality, and caused rDNA copy number variation. Semen quality was related to the rDNA copy number in whole blood, testicular tissue, and semen samples in mice.

CONCLUSION

Cr (VI) was associated with decreased semen quality in semen donors and mice. Our findings suggest an in-depth analysis of the role of the rDNA copy number variation in the Cr (VI)-induced impairment of semen quality.

Self-Rated Health and Semen Quality in Men Undergoing Assisted Reproductive Technology

Importance

Numerous studies have documented the association of self-rated health (SRH) with chronic diseases. However, few studies have investigated its association with semen quality.

Objective

To examine the association of SRH with semen quality among men undergoing assisted reproductive technology (ART) in China.

Design, Setting, and Participants

This cross-sectional study recruited male partners in couples undergoing ART treatment at the Center for Reproductive Medicine, Tongji Hospital, Wuhan, China. A total of 1262 men underwent 2 semen examinations and completed a questionnaire on SRH between December 2018 and January 2020. Data analysis was performed from November 20, 2022, to March 24, 2023.

Exposure

SRH, including overall physical and mental health, as well as reproductive-related physical and mental health specifically, were reported at baseline recruitment.

Main Outcomes and Measures

Sperm concentration, sperm progressive motility, sperm motility, and sperm count as semen quality parameters.

Results

The study included 1262 men with a mean (SD) age of 32.79 (5.25) years and body mass index of 24.37 (3.68). Men with poorer SRH had lower semen quality (eg, sperm concentration among poor vs very good overall physical health: percentage variation, -14.67%; 95% CI, -23.62% to -4.66%). Among 4 components of SRH, a greater reduction in semen quality was estimated for reproductive-related SRH compared with overall SRH, whereas the greatest reduction was observed for reproductive-related physical SRH. In comparison with men with very good reproductive-related physical SRH, men with poor reproductive-related physical SRH had differences of -24.78% (95% CI, -32.71% to -15.93%) and -25.61% (95% CI, -33.95% to -16.22%) in sperm count and concentration, respectively, and regression coefficients of -9.38 (95% CI, -12.01 to -6.76) and -9.24 (95% CI, -11.82 to -6.66) for sperm motility and sperm progressive motility, respectively.

Conclusions and Relevance

In this cross-sectional study of Chinese men, poorer SRH was associated with lower semen quality, and reproductive-related physical SRH was the most pronounced indicator. Our findings suggest that SRH, especially reproductive-related physical SRH, was a good indicator of semen quality, which should inform public and clinical regulatory decisions.

The effects of tobacco and cannabis use on semen and endocrine parameters in infertile males

Substances such as tobacco and cannabis can negatively modulate seminal parameters and sex hormones and lead to fertility problems in males. The present study aimed to determine the effect of cigarettes, dipping tobacco, and cannabis on semen parameters and sex hormones in infertile males. A total of 160 infertile healthy participants (cigarette smokers n = 40, dipping tobacco users n = 40, cannabis users n = 40 and infertile controls n = 40) were included in the study. Fasting blood samples were collected from all the participants using the aseptic technique, and semen samples were collected by masturbation following sexual abstinence of 2-7 days. The levels of serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined using ELISA. The serum level of FSH was significantly higher in cannabis users relative to the control group (p = 0.043). A mild non-significant decrease in sperm count, serum LH and testosterone levels were observed in all drug users compared to controls. In conclusion, chronic use of tobacco and cannabis mildly modulates semen and hormonal parameters in infertile males.

Decreased sperm counts in Swedish users of oral tobacco

Background

Smoke‐free tobacco via moist oral snuff (snus) is used daily in more than 20% of Swedish men. Negative effects of cigarette smoking on sperm parameters are well documented, unlike for snuff, despite relevance also for other smoke‐free nicotine products.

Objectives

We wanted to investigate whether reproductive parameters differed between users and non‐users of snuff, and whether the amount of snuff and nicotine exposure mattered.

Materials and methods

Men (n = 613) from the general population, recruited 2000–2010, were physically examined, answered questions on smoking and snuff use, and delivered urine, blood and semen samples. Sperm concentration, total sperm count, semen volume, percent morphologically normal and progressively motile sperm, and DNA fragmentation index (by the Sperm Chromatin Structure Assay) and reproductive hormones were analysed. Nicotine exposure was measured through urinary levels of cotinine. We used general linear models, with adjustments including cigarette smoking, and for semen parameters also abstinence time.

Results

After adjustments, total sperm count was 24% lower (P = 0.03) and testosterone 14% higher (P < 0.001) in 109 users of snuff than in non‐users, whereas cotinine was positively associated with testosterone and oestradiol (P < 0.001). Numbers of boxes of snuff used per week were associated with testosterone and FSH (P < 0.001).

Discussion

Applied to the general population, the consumption of smoke‐free tobacco by the use of snuff was associated with a lower sperm count and a higher testosterone, for which the extent seemed to play a role.

Conclusions

Independent of smoking, consumption of snuff was associated with lower total sperm count and different hormone levels. Applying these results to a reported association between sperm count and the chance of pregnancy, men who used snuff would have about a 10% lower chance of fathering a child.

Sperm count is increased by diet-induced weight loss and maintained by exercise or GLP-1 analogue treatment: a randomized controlled trial

STUDY QUESTION

Does diet-induced weight loss improve semen parameters, and are these possible improvements maintained with sustained weight loss?

SUMMARY ANSWER

An 8-week low-calorie diet-induced weight loss was associated with improved sperm concentration and sperm count, which were maintained after 1 year in men who maintained weight loss.

WHAT IS KNOWN ALREADY

Obesity is associated with impaired semen quality. Weight loss improves metabolic health in obesity, but there is a lack of knowledge on the acute and long-term effects of weight loss on semen parameters.

STUDY DESIGN, SIZE, DURATION

This is a substudy of men with obesity enrolled in a randomized, controlled, double-blinded trial (the S-LITE trial). The trial was conducted between August 2016 and November 2019. A total of 56 men were included in the study and assigned to an initial 8-week low-calorie diet (800 kcal/day) followed by randomization to 52 weeks of either: placebo and habitual activity (placebo), exercise training and placebo (exercise), the Glucagon Like Peptide 1 (GLP-1) analogue liraglutide and habitual activity (liraglutide) or liraglutide in combination with exercise training (combination).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Inclusion criteria were men who delivered semen samples, 18 to 65 years of age, and a body mass index between 32 and 43 kg/m2, but otherwise healthy. The study was carried out at Hvidovre Hospital and at the University of Copenhagen, and the participants were from the Greater Copenhagen Area. We assessed semen parameters and anthropometrics and collected blood samples before (T0), after the 8-week low-calorie dietary intervention (T1), and after 52 weeks (T2).

MAIN RESULTS AND THE ROLE OF CHANCE

The men lost on average 16.5 kg (95% CI: 15.2-17.8) body weight during the low-calorie diet, which increased sperm concentration 1.49-fold (95% CI: 1.18-1.88, P < 0.01) and sperm count 1.41-fold (95% CI: 1.07-1.87, P < 0.01). These improvements were maintained for 52 weeks in men who maintained the weight loss, but not in men who regained weight. Semen volume, sperm motility and motile sperm count did not change.

LIMITATIONS, REASONS FOR CAUTION

The S-LITE trial was a randomized controlled trial of weight loss maintenance. Analysis of semen was preregistered to explore the effects of weight loss and weight loss maintenance on semen parameters, but definite inferences cannot be made.

WIDER IMPLICATIONS OF THE FINDINGS

This study shows that sperm concentration and sperm count were improved after a diet-induced weight loss in men with obesity. Our findings indicate that either or both liraglutide and exercise as weight maintenance strategies may be used to maintain the improvements in sperm concentration and count.

STUDY FUNDING/COMPETING INTEREST(S)

This work is supported by an excellence grant from the Novo Nordisk Foundation (NNF16OC0019968), a Challenge Programme Grant from the Novo Nordisk Foundation (NNF18OC0033754) and a grant from Helsefonden. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent research centre at the University of Copenhagen, partially funded by an unrestricted donation from the Novo Nordisk Foundation (NNF18CC0034900). Saxenda (liraglutide) and placebo pens were provided by Novo Nordisk. Cambridge Weight Plan diet products for the 8-week low-calorie diet were provided by Cambridge Weight Plan. E.A.: shareholder, employee of ExSeed Health Ltd. Grant Recipient from ExSeed Health Ltd and listed on Patents planned, issued or pending with ExSeed Health Ltd; J.J.H.: consultant for Eli Lilly A/S and Novo Nordisk A/S. Lecture fees for Novo Nordisk A/S. Listed on Patents planned, issued or pending with the University of Copenhagen, Advocacy group for Antag Therapeutics and Bainan Biotech; S.M.: lecture fees for Novo Nordisk A/S. Recipient of Support for attending meetings from Novo Nordisk A/S. Advisory boards of Novo Nordisk A/S; Sanofi Aventis and Merck Sharp & Dohme. S.S.T.: research grant recipient Novo Nordisk. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

The trial was approved by the Ethical Committee of the Capital Region of Denmark (H-16027082) and the Danish Medicines Agency (EudraCT Number: 2015-005585-32). ClinicalTrials.gov identifier (NCT number): NCT04122716.

TRIAL REGISTRATION DATE

11 May 2016.

DATE OF FIRST PATIENT’S ENROLMENT

August 2016.

Use of e-cigarettes associated with lower sperm counts in a cross-sectional study of young men from the general population

STUDY QUESTION

Are use of e-cigarettes and snuff associated with testicular function as previously shown for conventional cigarettes and marijuana?

SUMMARY ANSWER

Use of e-cigarettes is associated with reduced semen quality but not with higher serum testosterone level as observed for conventional cigarette use. Snuff use was not associated with markers of testicular function.

WHAT IS KNOWN ALREADY

Cigarette smoking has previously been associated with higher testosterone levels and impaired semen quality, whereas it is unresolved whether use of e-cigarettes or snuff influence the testicular function.

STUDY DESIGN, SIZE, DURATION

This cross-sectional population-based study included 2008 men with information on cigarette and marijuana use (enrolled between 2012 and 2018), among whom 1221 men also had information on e-cigarette and snuff use (enrolled between 2015 and 2018).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Men (median age 19.0 years) from the general population provided a semen and blood sample and filled out a questionnaire on lifestyle including information on smoking behaviour. Associations between different types of smoking (e-cigarettes, snuff, marijuana and cigarettes) and reproductive hormones (total and free testosterone, sex hormone-binding globulin, LH, oestradiol and ratios of inhibin B/FSH, testosterone/LH and free testosterone/LH) and semen parameters (total sperm count and sperm concentration) were examined using multiple linear regression analyses adjusted for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Approximately half of the men (52%) were cigarette smokers, 13% used e-cigarettes, 25% used snuff and 33% used marijuana. Users of e-cigarettes and marijuana were often also cigarette smokers. Compared to non-users, daily e-cigarette users had significantly lower total sperm count (147 million vs 91 million) as did daily cigarette smokers (139 million vs 103 million), in adjusted analyses. Furthermore, significantly higher total and free testosterone levels were seen in cigarette smoking men (6.2% and 4.1% higher total testosterone and 6.2% and 6.2% higher free testosterone in daily smokers and occasional smokers, respectively, compared to non-smoking men), but not among e-cigarette users. Daily users of marijuana had 8.3% higher total testosterone levels compared to non-users. No associations were observed for snuff in relation to markers of testicular function.

LIMITATIONS, REASONS FOR CAUTION

We cannot exclude that our results can be influenced by residual confounding by behavioural factors not adjusted for. The number of daily e-cigarette users was limited and findings should be replicated in other studies.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first human study to indicate that not only cigarette smoking but also use of e-cigarettes is associated with lower sperm counts. This could be important knowledge for men trying to achieve a pregnancy, as e-cigarettes are often considered to be less harmful than conventional cigarette smoking.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from the Danish Ministry of Health (1-1010-308/59), the Independent Research Fund Denmark (8020-00218B), ReproUnion (20200407) and the Research Fund of the Capital Region of Denmark (A6176). The authors have nothing to disclose.

TRIAL REGISTRATION NUMBER

NA.

Physical and Sedentary Activities in Association with Reproductive Outcomes among Couples Seeking Infertility Treatment: A Prospective Cohort Study

BACKGROUND

The aim of this study was to investigate the association of physical activity (PA) with assisted reproductive technology (ART) treatment and pregnancy outcomes among couples seeking infertility treatment.

METHODS

This prospective cohort study was carried out among 128 infertile individuals (64 couples), entering the infertility clinic for ART procedures. Baseline PA (before entering any treatment) was assessed using accelerometry for both women and men. For every couple the infertility treatment outcomes were recorded.

RESULTS

The couples that required invasive ART procedures such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) spent less time in vigorous PA (-73 min/week per couple, woman + man) than those couples who became spontaneously pregnant after entering the study (p = 0.001). We observed no significant associations between the time spent in physical activities and positive pregnancy test or live birth.

CONCLUSIONS

Our results do not support a positive nor negative relation between the time the couples spent in physical activities and the chances of getting pregnant or having a baby among patients seeking infertility treatment. However, couples undergoing invasive ART procedures did less vigorous PA than couples that became spontaneously pregnant, suggesting that PA may interfere with their reproductive health.

Physical activity and sedentary time in relation to semen quality in healthy men screened as potential sperm donors

STUDY QUESTION

Is physical activity or sedentary time associated with semen quality parameters?

SUMMARY ANSWER

Among healthy men screened as potential sperm donors, higher self-reported physical activity was associated with increased progressive and total sperm motility.

WHAT IS KNOWN ALREADY

Despite the claimed beneficial effect of moderate physical activity on semen quality, results from epidemiological studies have been inconclusive. Previous studies were mostly conducted among endurance athletes or male partners of couples who sought infertility treatment.

STUDY DESIGN, SIZE, DURATION

Healthy men screened as potential sperm donors were recruited at the Hubei Province Human Sperm Bank of China. Between April 2017 and July 2018; 746 men completed the long-form International Physical Activity Questionnaire (IPAQ) and provided repeated semen samples (n = 5252) during an approximately 6-month period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Total metabolic equivalents (METs), moderate-to-vigorous METs and sedentary time were abstracted from the IPAQ. Sperm concentration, total sperm count, progressive motility and total motility in repeated specimens were determined by trained clinical technicians. Mixed-effect models were applied to investigate the relationships between physical activity and sedentary time and repeated measures of semen quality parameters.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for multiple confounders, total METs and moderate-to-vigorous METs were both positively associated with progressive and total sperm motility. Compared with men in the lowest quartiles, those in the highest quartiles of total and moderate-to-vigorous METs had increased progressive motility of 16.1% (95% CI: 6.4, 26.8%) and 17.3% (95% CI: 7.5, 27.9%), respectively, and had increased total motility of 15.2% (95% CI: 6.2, 24.9%) and 16.4% (95% CI: 7.4, 26.1%), respectively. Sedentary time was not associated with semen quality parameters.

LIMITATIONS, REASONS FOR CAUTION

The IPAQ was reported only once from study participants; measurement errors were inevitable and may have biased our results. Furthermore, although we have adjusted for various potential confounders, the possibility of unmeasured confounding cannot be fully ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that maintaining regular exercise may improve semen quality parameters among healthy, non-infertile men. Specifically, we found that higher self-reported total and moderate-to-vigorous METs were associated with improved sperm motility, which reinforces the existing evidence that physical activity may improve male reproductive health.

STUDY FUNDING/COMPETING INTEREST(S)

Y.-X.W was supported by the Initiative Postdocs Supporting Program (No. BX201700087). A.P. was supported by the National Key Research and Development Program of China (2017YFC0907504). C.-L.X. was supported by the National Key Research and Development Program of China (2016YFC1000206). The authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Birth characteristics in men with infertility

RESEARCH QUESTION

Are low birth weight, prematurity, being born small for gestational age, or both, associated with a higher risk of male factor infertility in adulthood?

DESIGN

Retrospective study of a clinical sample of 892 men, diagnosed with an infertility factor (male, female, combined or unexplained) together with their female partner at a University Hospital clinic in Sweden between 2005 and 2010. Data on birth weight and gestational age at birth were retrieved from the Swedish Medical Birth Register. The distribution of non-optimal birth characteristics in relation to infertility factor was described. A control group was created consisting of two men for each index man, born in Sweden in the same year as each index men, as well as a reference group consisting of all men born in Sweden the same years.

RESULTS

The likelihood of having been born small for gestational age was almost fivefold higher in men with male factor infertility than in men with unexplained infertility (OR 4.84, 95% CI 1.32 to 17.80). Men with male factor infertility were more often born with non-optimal birth characteristics than the control group (14.8% versus 8.5%; P = 0.010) and the reference group (14.8% versus 11.4%; P < 0.001). Men with azoospermia were more often born with non-optimal birth characteristics, compared with men without azoospermia (21.3% versus 12.1%; P = 0.038).

CONCLUSIONS

The results suggest an association between intrauterine growth restriction and male factor infertility in adulthood.

Maternal physical activity and sedentary behaviour before and during in vitro fertilization treatment: a longitudinal study exploring the associations with controlled ovarian stimulation and pregnancy outcomes

PURPOSE

To evaluate the association of objectively measured physical activity (PA) and sedentary behaviour before and during in vitro fertilization (IVF) with controlled ovarian stimulation (COS) and pregnancy outcomes.

METHODS

This longitudinal study involved 107 infertile women undergoing IVF treatment. PA and sedentary behaviour were measured for 14 consecutive days using accelerometry as follows: (1) before IVF treatment, (2) during IVF at the implantation time, immediately after embryo transfer, and (3) after positive pregnancy test. Total screen time was assessed by questionnaires. COS results were measured as the number of oocytes and embryos obtained, and the study outcomes included positive hCG, clinical pregnancy, and live birth.

RESULTS

Compared with baseline activity levels, women significantly reduced their PA and increased sedentary behaviour during IVF (p ≤ 0.001). Higher average PA, light PA, and ratio between breaks in every ≥ 30-min blocks of sedentary time showed positive associations, while sedentary time, number, and time accumulated in blocks of ≥ 30 min of sedentary time associated negatively with oocyte and embryo counts (all p < 0.05). Women with high total screen time during non-work days (≥ 7 h) obtained 4.7 oocytes (p = 0.005) and 2.8 embryos (p = 0.008) less in COS. PA and sedentary behaviour before and during IVF did not affect the positive hCG, clinical pregnancy, and live birth outcomes.

CONCLUSION

Our study results suggest that higher time spent in PA and lower time spent in sedentary behaviour before entering assisted reproduction is associated with better COS outcomes, while activity levels before and during IVF do not affect the implantation, pregnancy, and live birth outcomes.

Association of the Dietary Approaches to Stop Hypertension, Physical Activity, and Their Combination with Semen Quality: A Cross-Sectional Study

The influence of individual lifestyle factors is widely described in studies on semen quality. However, their synergistic effect is often neglected. The aim of the study was to examine the association between semen quality and dietary approaches to stop hypertension (DASH) diet, physical activity (PA), and the two separately and in combination. A cross-sectional study was carried out among 207 men aged 20–55. Dietary data were collected by a food frequency questionnaire (FFQ) and analysed according to the DASH scoring index. Physical activity was evaluated by the International Physical Activity Questionnaire. Semen parameters were assessed via the computer-aided semen analysis (CASA). Adherence to the DASH diet was associated with higher sperm count (Δ_T3-T1 = 82.1 mln/ej) and concentration (Δ_T3-T1 = 24.6 mln/mL). Higher PA was related to higher sperm count (Δ_T3-T1 = 69.4 mln/ej), total (Δ_T3-T1 = 11.9%), and progressive motility (Δ_T3-T1 = 8.5%) and morphology (Δ_T3-T1 = 2.8%) in the crude model and remained significant after adjustment. The combination of the DASH diet and PA, was significantly positively associated with sperm count (Δ_T3-T1 = 98.1 mln/ej), sperm concentration (Δ_T3-T1 = 17.5 mln/mL), total (Δ_T3-T1 = 11.8%), and progressive motility (Δ_T3-T1 = 10.0%) and morphology (Δ_T3-T1 = 3.3%) in both models. Adherence to the DASH diet was related to higher sperm count and concentration, whereas after its combination with physical activity it was also positively correlated with sperm motility and morphology.

Sedentary behavior, physical inactivity and body composition in relation to idiopathic infertility among men and women

BACKGROUND

Physical activity (PA) and sedentary behavior have inconsistent effects on fertility. High body mass index is associated with infertility but to our knowledge, very few studies have explored body composition in association to fertility.

OBJECTIVE

To assess the association between physical inactivity, sedentary behavior, body composition and idiopathic infertility in French men and women.

DESIGN

We conducted a case-control multicentric observational study. 159 infertile (79 men and 80 women) and 143 fertile (72 men and 71 women) were recorded in four fertility centers.

MAIN OUTCOME MEASURES

Participants completed self-administered questionnaires on sociodemographic and lifestyle characteristics, dietary intake, physical activity and sedentary behavior. Anthropometrics were measured, and bioelectrical impedance analysis was used to estimate body composition. Multivariable logistic regression was used to analyze the association of fertility with PA level and sedentary behavior.

RESULTS

In men, being physically inactive (Odd ratio [OR] 2.20; 95% confidence interval [CI], 1.06, 4.58) and having fat mass greater than the reference values for their age (OR 2.83; 95%CI, 1.31, 6.10) were positively associated with infertility. Sedentary behavior and fat-free mass were not related to infertility in men. In women, sedentary behavior (OR 3.61; 95%CI, 1.58, 8.24), high body fat (OR 3.16; 95%CI, 1.36, 7.37) and low fat-free mass (OR 2.65; 95%CI, 1.10, 6.37) were associated with infertility. PA level was not associated with fertility in women.

CONCLUSIONS

This study suggests that sedentary behavior and physical inactivity would represent two independent risk factors associated with infertility. The various elements that make up physical activity (frequency, intensity, time, and type of exercise) and the interrupting time spent sitting should be considered. Body composition variation should be explored further in relation to the biological pathways involved in idiopathic infertility. Moreover, the improvement of lifestyle factors should be considered in infertility treatment.

Impact of physical activity on semen quality among men from infertile couples

OBJECTIVE

To determine the implication of general physical activity and some specific sports in semen quality in men from infertile couples.

STUDY DESIGN

This is an observational study performed in men from infertile couples (n = 454). The interventions performed involved analyzing semen quality parameters according to 2010 WHO criteria and assessing physical activity by means of an International Physical Activity Questionnaire.

RESULT(S)

There was no association between different levels of general physical activity and semen parameters. We neither found association with running, cycling and racquet sports. Interestingly, people who practice weightlifting more than two hours per week presented significantly lower sperm concentration (linear coefficient = -24.80) and lower total sperm count (linear coefficient = -70.87) in comparison with participants that did not practice regular exercise.

CONCLUSION(S)

From a reproductive point of view, there does not seem to be any reason to recommend the increase or the decrease in general physical activity in males from infertile couples. However, additional studies are needed to investigate the relationship between weightlifting and sperm quality.

Association between paternal smoking at the time of pregnancy and the semen quality in sons

BACKGROUND

Maternal smoking during pregnancy has repeatedly been associated with decreased sperm counts in sons. Nevertheless, our team recently detected a lower total sperm count in the sons of smoking fathers as compared to sons of non-smoking fathers. Since paternal and maternal tobacco smoking often coincide, it is difficult to discriminate whether effects are mediated paternally or maternally when using questionnaire- or register-based studies. Therefore, getting an objective measure of the maternal nicotine exposure level during pregnancy might help disentangling the impact of paternally and maternally derived exposure.

OBJECTIVES

Our aim was to study how paternal smoking at the time of the pregnancy was associated with semen quality in the sons after adjusting for the maternal levels of nicotine exposure during pregnancy.

METHODS

We recruited 104 men (17-20 years old) from the general Swedish population. The participants answered a questionnaire about paternal smoking. Associations between smoking and semen volume, total sperm count, sperm concentration, morphology and motility were adjusted for levels of the nicotine metabolite cotinine in stored maternal serum samples obtained from rubella screening between the 6th and 35th week of pregnancy. We additionally adjusted for the estimated socioeconomic status.

RESULTS

After adjusting for the maternal cotinine, the men of smoking fathers had 41% lower sperm concentration and 51% lower total sperm count than the men of non-smoking fathers (p = 0.02 and 0.003, respectively). This was robust to the additional adjustment.

CONCLUSIONS

Our results suggest a negative association between paternal smoking and sperm counts in the sons, independent of the level maternal nicotine exposure during the pregnancy.

Sports-related Male Infertility

Many common sports and sports-related behaviors and practices represent potential sources of male infertility. Clinicians should be aware of these associations in the evaluation of idiopathic infertility in men.

Geographical differences in semen characteristics of 13 892 infertile men

Objective

To assess the relationship between geographical differences and all semen parameters, across 13,892 infertile men of 84 diverse nationalities, recruited at a specialised tertiary hospital that represents the main healthcare provider in Qatar. Male infertility is an important and global public health problem. Despite this, there is a significant scarcity of epidemiological male infertility and semen analysis research in the Middle East and North Africa (MENA) region, as well as geographical comparisons with other parts of the world.

Patients and methods

Retrospective study of semen findings of 13 892 infertile men assessed at the Male Infertility Unit at Hamad Medical Corporation, in Qatar between January 2012 and August 2015. Based on country of origin, patients were categorised into those from the MENA region (n = 8799) and non-MENA patients (n = 5093). The two groups were compared across demographic features and semen characteristics: age, sperm volume, sperm total motility, sperm progressive motility (PMot), abnormal sperm forms (ABF), and sperm DNA fragmentation (SDF).

Results

The whole sample's mean (SD) age was 35.7 (0.7) years, sperm concentration was 32.3 (0.25) × 10⁶ sperm/mL, total motility was 45.4 (0.2)%, sperm PMot was 25.1 (0.2)%, and ABF was 79.9 (0.2)%. Overall, 841 patients had azoospermia (6.05%), 3231 had oligospermia (23.3%), 4239 had asthenospermia (30.5%) and 6772 had teratospermia (48.7%). SDF (1050 patients) was abnormal in 333 patients (31.7%). MENA patients were significantly younger than their non-MENA counterparts and had a greater semen volume. Non-MENA patients had significantly higher sperm counts, total motility and PMot, and lower ABF. SDF showed no statistical difference between the two groups. MENA patients had significantly higher prevalence of oligospermia, asthenospermia, and teratospermia; and lower prevalence of normal sperm concentration, normal motility, and normal morphology. Throughout the 4 years of the study, MENA patients constantly had significantly lower sperm counts; generally lower sperm total motility percentage and generally lower quality sperm morphology. We compared patients by age (≤40 and >40 years): in the patients aged ≤40 years, the same results as for the overall study were reproduced; in the >40-years group, the same results were reproduced with the exception of morphology, which was not significantly different between the MENA and non-MENA patients.

Conclusion

Semen quality is generally lower in male infertility patients from the MENA region compared to non-MENA regions.

Lifestyle-Related Factors Associated with Reproductive Health in Couples Seeking Fertility Treatments: Results of A Pilot Study

Background

The objective of this pilot study was to evaluate the feasibility of conducting a larger prospective cohort study, which will aim at determining the independent contribution of male and female lifestyle-related factors to assisted reproductive technology (ART) success. The study also examined whether couples seeking fertility treatments present lifestyle-related factors that may interfere with their reproductive health.

MATERIALS AND METHODS

This prospective pilot study was conducted in a fertility clinic between May 2015 and February 2016. Feasibility factors evaluated were recruitment rates, compliance with the protocol, retention rate and ART outcomes at six-month follow-up. Anthropometric profile and lifestyle habits of both partners were evaluated before the beginning of infertility treatments.

RESULTS

We approached 130 eligible infertile couples. Among them, 32 (25%) agreed to participate and 28 (88%) complied with the protocol. At six-month follow-up, seven couples (25%) did not start, or stop, infertility treatments and 13 couples (62%) achieved a clinical pregnancy. Among the 28 couples included in the analyses, 16% of the partners were obese and 23% had abdominal obesity. The majority of the subjects were still drinking alcohol (84%). Sixty-eight percent of women needed improvement in their diet (vs. 95% of men, P=0.05) and none of them achieved the Canadian recommendations for physical activity (vs. 33% of men, P=0.001). Moreover, 35% of the partners had a poor sleep quality. Overall, women presented a worse reproductive health profile than men, with 3.1 and 2.4 out of seven adverse factors, respectively (P=0.04).

CONCLUSION

Conducting a large prospective cohort study in our fertility clinic will be feasible but recruitment and compliance with the protocol need to be improved. Many women and men seeking fertility treatments present unfavourable lifestyle-related factors that may explain, at least partially, their difficulties in conceiving.

Physically Active Men Show Better Semen Parameters than Their Sedentary Counterparts

Background

The quality of semen depends upon several factors such as environment, life style, physical activity, age, and occupation. The aim of this study was to analyze and compare the conventional and functional semen parameters in men practicing vigorous physical activity to those of sedentary men.

Materials and Methods

In this descriptive cross-sectional study, semen samples of 17 physically active men and 15 sedentary men were collected for analysis. Semen analysis was performed according to the World Health Organization (WHO) guidelines, while functional parameters were evaluated by flow cytometry.

Results

Results showed that several semen parameters (semen volume, viability, progressive motility, total motility, normal morphology, and moribund cells) were superior in the physically active group in comparison with the sedentary group. Semen parameters such as viability, progressive motility and total motility, as well as the percentage of moribund spermatozoa were significantly different between both groups. However, sperm DNA damage, lipid peroxidation and mitochondrial potential were not significantly different among the groups.

Conclusion

Nevertheless, the physical activity shows better semen parameters than sedentary group. Taken together, our results demonstrate that regular physical activity has beneficial impact in sperm fertility parameters and such a life style can enhance the fertility status of men.

Associations between male reproductive characteristics and the outcome of assisted reproductive technology (ART)

The present study was designed to investigate the relationships between indicators of male body mass index (BMI), age, reproductive hormone levels, semen parameters, and the outcomes of assisted reproductive technology (ART). The clinical data were collected from 636 couples who underwent ART between January, 2013 and December, 2015 at the reproductive center involved in our study. Pearson’s correlation or Spearman rank correlation was applied to establish the relevant correlation coefficients. The correlation between influence factors’ and pregnancy outcomes was analyzed using the Logistic regression model. Analyses were conducted using SPSS software. Male BMI was found to be negatively correlated with testosterone (T) (P<0.05), while follicle-stimulating hormone (FSH) was negatively correlated with semen parameters (P<0.05). Luteinizing hormone (LH) was found to be negatively correlated with total sperm count, normal sperm morphology, and abortion (all P<0.05). Clinical pregnancy was related to sperm concentration and female age (P<0.05), and live birth was found to be associated only with female age (P<0.05). Male BMI was associated with the secretion of reproductive hormones, but had no effect on sperm parameters or ART outcome. A higher male age was also negatively connected with the outcome of clinical pregnancy. Reproductive hormones were not associated with ART outcome. Sperm concentration and female age were important factors influencing ART clinical pregnancy, while the only significant factor influencing live birth was female age. Levels of obesity-related inflammatory indicators (i.e. free fatty acid (FFA), glutathione peroxidase (GSH-Px), human inhibin-B (IHNB), interleukin-1 (IL-1), insulin-like growth factor-1 (IGF-1), and reactive oxygen species (ROS)) also varied with degrees of BMI. The present study provides information on the associations between male reproductive characteristics and the outcome of ART, which may contribute to improved strategies to help couples achieve better pregnancy outcomes.

Exploring men's pregnancy-planning behaviour and fertility knowledge:a survey among fathers in Sweden

INTRODUCTION

Research about pregnancy-planning behaviour mostly focuses on women, even though pregnancy planning usually also concerns men. The purpose of this study was to investigate how men plan for family, and to measure their fertility knowledge after having become fathers.

MATERIAL AND METHODS

Data were collected in 2014 as part of a Swedish longitudinal pregnancy-planning study. Men were recruited through their female partner one year after childbirth. Participants were asked to fill out a questionnaire about pregnancy planning, lifestyles, and fertility.

RESULTS

Of the 796 participants, 646 (81%) stated that the pregnancy had been very or fairly planned, and 17% (n = 128) had made a lifestyle adjustment before pregnancy to improve health and fertility. The most common adjustments were to reduce/quit the consumption of alcohol, cigarettes, or snuff, and to exercise more. First-time fathers and those who had used assisted reproductive technology to become pregnant were more likely to have made an adjustment. Fertility knowledge varied greatly. Men with university education had better fertility knowledge than men without university education.

CONCLUSION

Our findings indicate that there is variation in how men plan and prepare for pregnancy. Most men did not adjust their lifestyle to improve health and fertility, while some made several changes. Both pregnancy-planning behaviour and fertility knowledge seem to be related to level of education and mode of conception. To gain deeper understanding of behaviour and underlying factors, more research is needed.

Association between adherence to the Mediterranean diet and semen quality parameters in male partners of couples attempting fertility

STUDY QUESTION

Is adherence to the Mediterranean diet (MedDiet) associated with better semen quality in men of subfertile couples attempting fertility?

SUMMARY ANSWER

Greater adherence to the MedDiet, as assessed through the validated Mediterranean diet score (MedDietScore), was significantly associated with higher sperm concentration, total sperm count and sperm motility.

WHAT IS KNOWN ALREADY

A-posteriori dietary pattern approaches have revealed that dietary patterns characterized by high intakes of fruits, vegetables, whole grains, fish and low intake of meat are associated with better semen quality. Yet, whether adherence to the MedDiet is associated with better semen profile remains largely unexplored.

STUDY DESIGN, SIZE, AND DURATION

This was a cross-sectional study of 225 men from couples attending a fertility clinic in Athens, Greece, recruited between November 2013 and May 2016. The study was designed to evaluate the influence of habitual dietary intake and lifestyle on fertility outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Men aged 26-55 years, 51.1% overweight or obese, 20.9% smokers, with complete dietary data were analyzed. Diet was assessed via a food-frequency questionnaire and adherence to the MedDiet was assessed through the MedDietScore (range: 0-55; higher scores indicating greater adherence to MedDiet). Semen quality was evaluated according to World Health Organization 2010 guidelines. Multiple logistic regression analysis was used to evaluate associations between tertiles of the MedDietScore and the likelihood of having abnormal semen parameters, after adjusting for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to men in the highest tertile of the MedDietScore (≥37, N = 66), a higher percentage of men in the lowest tertile of the score (≤30, N = 76) exhibited below the WHO reference values for sperm concentration (47.4% vs 16.7%, P < 0.001), total sperm count (55.3% vs 22.7%, P < 0.001), total motility (65.8% vs 31.8%, P < 0.001), progressive motility (84.2 vs 62.1%, P = 0.011) and sperm morphology (50.0 vs 28.8%, P = 0.023). In the multivariable adjusted models, men in the lowest tertile of the MedDietScore had ~2.6 times higher likelihood of having abnormal sperm concentration, total sperm count and motility, compared to men in the highest tertile of the score.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of the study stems from its cross-sectional nature, limiting our ability to determine causality.

WIDER IMPLICATIONS OF THE FINDINGS

The results suggest that greater compliance to the MedDiet may help improve semen quality. Whether this translates into differences in male fertility remains to be elucidated. Our findings are consistent with previous studies showing that dietary patterns with some of the characteristics of the MedDiet, i.e. rich in fruit, vegetables, legumes and whole grains, are associated with better measures of semen quality.

STUDY FUNDING/COMPETING INTERESTS

No funding was obtained. The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

n/a.

Time-to-Pregnancy Associated With Couples' Use of Tobacco Products

INTRODUCTION

Previous studies suggest female smoking increases time-to-pregnancy (TTP), a couple-dependent reproductive outcome, while associations with male smoking are more ambiguous. Furthermore, despite small increases in smokeless tobacco use in the United States, no prior study has evaluated TTP among smokeless tobacco users.

METHODS

Using population-based sampling in 16 counties in Michigan and Texas, 501 couples discontinuing contraception to become pregnant were followed until positive pregnancy test or 12 months of trying. Participants were interviewed on lifetime and current cigarette, cigar, and chew/snuff (smokeless) use and provided blood samples for quantification of heavy metals and cotinine. Fecundability odds ratios (FORs) and 95% confidence intervals (95% CIs) were estimated, adjusted for demographics/lifestyle. FORs less than 1 reflect longer TTP.

RESULTS

Eleven percentage of females and 15% of males smoked cigarettes. Among men, 14% smoked cigars, 9% used snuff, and 2% used chew. Compared with never tobacco users, male (FOR: 0.41, 95% CI: 0.24, 0.68) and female (FOR: 0.53, 95% CI: 0.33, 0.85) smoking were individually associated with longer TTP; males' smoking remained significant (FOR: 0.46, 95% CI: 0.27, 0.79) when modeling partners together. Cadmium levels were higher in smokers than smokeless tobacco and never users; adjusting for cadmium attenuated the cigarette-TTP association, particularly among women. TTP was shorter among smokeless tobacco users relative to smokers (FOR: 2.86, 95% CI: 1.47, 5.57).

CONCLUSIONS

Compared with never users, smokeless tobacco did not alter TTP in our cohort; however, TTP was shorter compared with smokers. We observed longer TTP in male and female smokers; cadmium may partially contribute.

IMPLICATIONS

Both partners' preconception smoking contributed to longer TTP, highlighting the importance of both partners' lifestyles in healthy reproduction and underscores the need for couple-based preconception guidance. The male's contribution is a new finding. Higher cadmium levels may partially contribute to longer TTP in smokers, particularly among females. Though we do not observe longer TTP among a small sample of smokeless tobacco users compared with never tobacco users, we observe shorter TTP compared with smokers. Further work is needed to more thoroughly delineate the relationship between smokeless tobacco use and TTP and possible mechanisms of tobacco use's effects on reproduction.