Effects of ejaculatory frequency and season on variations in semen quality

Association of abstinence time with semen quality and fertility outcomes: a systematic review and dose-response meta-analysis

BACKGROUND

Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor infertility, but sperm parameters can be influenced by ejaculatory abstinence (EA) duration. Shortening or prolonging EA can impact on semen quality and assisted reproductive technology (ART) outcomes, but the optimal EA duration remains unclear, particularly for infertility patients.

OBJECTIVES

This study conducts a comprehensive meta-analysis to explore the impact of varying abstinence durations on semen quality and fertility outcomes.

METHODS

Three English database (PubMed, Embase, and Cochrane Central Register of Controlled Trials) as well as four Chinese database (China National Knowledge Infrastructure, Chinese Scientific Journals database, WanFang database, and Chinese Biomedical Literature database) were searched from 2000 to August 2023. The classical meta-analysis and "one-stage" dose-response meta-analysis were conducted to compare the associations of different abstinence durations (short-term abstinence vs. long-term abstinence) on semen quality in healthy adult and different type of infertile patients.

RESULTS

There were 85 eligible studies were finally included. The meta-analysis of volume (mean difference [MD] = -0.95 mL, 95% confidence interval [CI]: -1.16 to -0.74 mL), total sperm count (TSC) (MD = -102.45×106, 95% CI: -117.98×106 to -86.91×106), sperm concentration (SC) (MD = -11.88×106/mL, 95% CI: -18.96×106/mL to -4.80×106/mL), DNA fragmentation index (DFI) (MD = -2.37%, 95% CI: -4.73% to -0.01%) in healthy men showed a significant decrease with different abstinence durations (short-term abstinence vs. long-term abstinence). The meta-analysis of infertile men showed significant decrease in volume in various subgroups (MD range: -0.73 to -1.17 mL) with P < 0.01; TSC (MD = -61.93×106, 95% CI: -88.84×106 to -35.01×106), SC (MD = -5.39×106/mL, 95% CI: -9.97×106 to -0.81×106/mL), DFI (MD = -5.63%, 95% CI: -10.19% to -1.06%) in unexplained infertility subgroup; significant increase in viability (MD = 6.14%, 95% CI: 3.61% to 8.68%) in the unexplained infertility subgroup. The dose-response meta-analysis showed that TSC in oligozoospermia showed a nonlinear increase (coefficient from 3.38 to -5.76, P from 0.02 to 0.22) and the truncation point was around the 4th to 5th abstinence day. The percentage of progressive motile sperm (PR) in asthenozoospermia showed a significant decrease (coefficient = -2.39, 95% CI: -4.28 to -0.50). For fertility outcomes of different ARTs, only the clinical pregnancy rate (CPR) in the intrauterine insemination (IUI) subgroup showed a significant decrease around the 3rd day (coefficient = 0.85, 95% CI: 0.75 to 0.97).

CONCLUSIONS

Short-term abstinence may be associated with limited improvements in semen quality in healthy men but could be more beneficial for infertile men, especially within the first 4 days of abstinence. Caution is urged in making definitive conclusions about the causal relationship between abstinence time and semen quality changes due to potential confounding and interactions.

The relationship between semen quality in male infertility clinic patients and bisphenol A：A Chinese cross-sectional study

Bisphenol A (BPA) is a growing concern as an endocrine-disrupting chemical due to its adverse health effects. However, the association between BPA and sperm quality in adult human males remains unclear. The aim of this study was to assess the daily life exposure level of BPA and analyze its correlation with sperm quality in males. Patients who sought treatment in Chinese infertility clinics between May and October 2023 were selected as study subjects. We determined participants' serum BPA content using high-performance liquid chromatography. Sperm count and motility were assessed using a computer-aided sperm analysis system, while sperm morphology was analyzed using an improved Papanicolaou stain. A total of 405 participants, averaging 33.01 ± 5.44 years old, were included. We observed low semen quality among participants in infertility clinics. Principal component analysis was performed for each semen quality index, and three principal components reflecting sperm motility, count, and morphology were extracted. The participants' mean serum BPA level was 6.96 ng/mL. Negative correlations were observed between serum BPA content and total sperm count, sperm density, forward motility rate, and non-forward motility rate. A positive correlation was found between the non-motile sperm rate and the head deformity rate. Morphological abnormalities were the predominant adverse effects observed. Despite low daily life BPA exposure, long-term low-dose exposure in the general population may damage semen quality. This study provides a scientific basis for managing health risks associated with BPA exposure.

[First-line management of infertile couple. Guidelines for clinical practice of the French College of Obstetricians and Gynecologists 2022]

OBJECTIVE

To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples.

MATERIALS AND METHODS

Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts.

RESULTS

The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery.

CONCLUSION

Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples.

Relationship of environmental exposure temperature and temperature extremes on sperm DNA fragmentation index in men with different BMI values and the indirect effect of DNA fragmentation index on semen parameters

Prior studies have established a significant correlation between the DNA fragmentation index (DFI) and infertility. Additionally, certain investigations suggest that environmental exposure may serve as an etiological factor impacting semen quality. This study aimed to explore the impact of season, ambient temperature, and weather extremes on the DFI of sperm, along with other relevant parameters. Furthermore, it sought to assess how ambient temperature affects the DFI of sperm and other semen parameters in populations with varying BMI values. Additionally, the study analyzed the transient indirect effect of DFI on sperm parameters. This retrospective study analyzed semen samples from 11,877 men, selected based on female factor considerations, spanning from January 2016 to December 2021. Participants were grouped according to the season of semen collection. The results showed that samples collected in summer had a lower semen volume and sperm motility, while those collected in autumn had a lower DFI. We analyzed the exposure-response ratio between environmental exposure temperature and semen parameters using a generalized additive model. Results showed that the curve of the exposure-response relationship was U-shaped or inverted U-shaped; when the air temperature exposure was below the threshold, for each degree of temperature increase, the total sperm motility, sperm concentration, and progressive motility increased by 0.16 %, 0.29 × 10 (Levine, 1999)/ml and 0.14 %, respectively, while the DFI and inactivity rate decreased by 0.078 % and 0.15 %, respectively. When the air temperature exposure exceeded the threshold, for each degree of temperature increase, the sperm concentration, total sperm motility, semen volume and progressive motility decreased by 0.42 × 10 (Levine, 1999)/ml, 0.11 %, 0.0078 ml and 0.15 %, respectively, while the DFI and inactivity rate increased by 0.13 % and 0.12 %, respectively. Extremely cold weather during spermatogenesis was positively correlated with DFI, and extremely hot weather was negatively correlated with sperm motility. Subgroup analysis revealed that individuals classified as overweight / obese exhibited more pronounced changes in sperm parameters and the DFI in response to variations in environmental exposure temperature compared to those with a normal BMI. In the analysis of the relationship between DFI and sperm parameters, the results showed an inverted U-shape relationship between DFI and semen volume, and a negative correlation between DFI and sperm concentration and sperm motility. And we found that ambient temperature affects sperm parameters through DFI at low as well as average temperatures, whereas at high temperatures this indirect effect is no longer present.

Impact of Season Variation on Semen Quality: A Comprehensive Retrospective Analysis of Data From Patients at an Eastern Iranian Tertiary Care Fertility Center Over a Decade

Seasonal changes are assumed to affect various sperm characteristics based on photoperiods, temperature, and air pollution. According to the literature, most studies were performed on populations of Western countries, and there are limited studies performed in the Middle East with variable results. This study evaluated the seasonality of sperm characteristics among men of reproductive age in an andrology center in Kerman, Iran, where the seasonal temperature varies significantly, with average temperatures ranging from 50 °F (10 °C) to 75.2 °F (24 °C). We retrospectively evaluated the sperm analysis test record. Sperm samples were obtained from 2,948 men during 10 years, excluding those with azoospermia. Samples were assessed for volume, concentration, motility, and morphology according to the World Health Organization (WHO) criteria. We performed a comprehensive comparative literature review of the studies investigating the association between seasonal variation and sperm quality. The mean semen volume was higher in the summer compared with other seasons (p = .04). The mean percentage of sperm motility was higher in the spring and less in winter (p = .03). Sperm morphology-related parameters, measured by the percent of normal morphology, were significantly better in winter (p = .03). Our findings suggest seasonality of sperm characteristics among men of fertility age. Semen volume, motility, and morphology were affected by the photoperiod of reproductive seasons. Results might support the influential role of seasonal variations in the possibility of fertility, especially among those using assisted reproductive technologies and those with oligospermia.

Mediation of association between semen microcystin exposure and semen quality by sex hormones in Chinese men

Numerous studies have shown microcystins (MCs) inducing male reproductive toxicity, but the underlying mechanisms in humans are unclear. Therefore, this study aimed to evaluate the mediating role of serum sex hormones in the association between MC exposure and semen quality. In this study, we measured the levels of semen MCs and serum sex hormones in Chinese men [sample 1 (n = 649); sample 2 (n = 924)]. The results showed that there was a non-significant dose-dependent relationship between semen MCs and semen volume reduction (p for trend = 0.079) in sample 1, and semen MCs were significantly negatively associated with total motility, progressive motility, curvilinear velocity, mean angular displacement and acrosome integrity (p < 0.05) in sample 2. We also found that semen MCs were significantly positively associated with serum follicle stimulating hormone (FSH) (β = 0.151; 95% CI: 0.065, 0.236), but negatively associated with serum inhibin B (INHB) (β = -0.605; 95% CI: -0.944, -0.265), and these linear associations were confirmed in restricted cubic spline (RCS) models (all pnon-linearity > 0.1). Furthermore, mediation analysis revealed that serum INHB mediated 19.86% of the adverse effect of MC exposure on acrosome integrity. In conclusion, this study reveals the mediating roles of serum sex hormones in the relationship between MC exposure and decreased semen quality in men.

The Association between Abstinence Period and Semen Parameters in Humans: Results in Normal Samples and Different Sperm Pathology

BACKGROUND

The impact of sexual abstinence on sperm quality, particularly in pathological cases, is a subject of debate. We investigated the link between abstinence duration and semen quality in both normal and pathological samples.

METHODS

We analyzed semen samples from 4423 men undergoing fertility evaluation, comprising 1256 samples from healthy individuals and 3167 from those with conditions such as oligozoospermia, asthenozoospermia, teratozoospermia, or a combination of these factors, namely oligoasthenoteratozoospermia (OAT). Parameters including sperm concentration, the percentage of progressively motile spermatozoa, total motile sperm count, and the percentage of spermatozoa with normal morphology were assessed at various abstinence durations (each day, 0-2, 3-7, and >7 days).

RESULTS

Extended abstinence correlated with higher sperm concentration overall (p < 0.001), except in oligozoospermia. Longer abstinence reduced progressive motility in normal (p < 0.001) and teratozoospermic samples (p < 0.001). Shorter abstinence was linked to higher morphologically normal sperm in normal samples (p = 0.03), while longer abstinence did so in oligoasthenoteratozoospermic samples (p = 0.013).

CONCLUSION

The findings suggest that a prolonged abstinence time is linked to higher sperm concentration, while optimal sperm motility is observed after shorter abstinence periods. However, results regarding morphology remain inconclusive. Recommendations on abstinence duration should be tailored based on the specific parameter requiring the most significant improvement.

Collecting semen samples at home for fertility assessment: time for a new standard?

BACKGROUND

In fertility clinics the standard approach to semen collection involves a private room close to the laboratory to avoid fluctuations in temperature and to control the time between collection and processing. There are still no firm conclusions whether collecting semen at home has any influence on sperm quality and reproductive competence. The purpose of this study was to assess whether the site of semen collection affects semen parameters.

METHODS

This retrospective cohort study performed at a tertiary level public fertility center included 8634 semen samples from 5880 men undergoing fertility assessment from 2015 to 2021. The impact of sample collection site was evaluated using a generalized linear mixed model. A subgroup analysis comparing clinic to home collection within the same patient was performed on 1260 samples from 428 men by paired t-test or Wilcoxon Signed Rank Test.

RESULTS

Samples collected at home (N.=3240) had significantly higher semen volume, sperm concentration and total sperm count respect to samples collected at clinic (N.=5530) (median (range): 2.9 (0.0-13.9) mL versus 2.9 (0.0-11.5) mL, P=0.016; 24.0 (0.0-252.0) million/mL versus 18.0 (0.0-390.0), P<0.0001; 64.6 (0.0-946.0) million versus 49.3 (0.0-1045.0), P<0.0001, respectively). There was no difference in abstinence period and sperm motility. Paired comparisons of semen characteristics in 428 patients with home-collected (N.=583) and clinic-collected (N.=677) samples confirmed a no negative effect on volume and total sperm count.

CONCLUSIONS

Our data provide evidence for a not disadvantage with collection at home.

Fluctuations in Seminal Quality throughout the Year: How do Temperature, Humidity and Atmospheric Pressure Impact on Human Sperm Quality?

Background

Most studies evaluating the possible seasonal variation of semen quality have considered temperature as the only causal factor.

Aims

To assess possible seasonality in sperm quality and associations between semen parameters and several meteorological variables (temperature, humidity, apparent temperature and atmospheric pressure) in a large cohort of andrological patients.

Settings and Design

This was a retrospective, cross-sectional and correlational/descriptive study.

Materials and Methods

Patients (n: 15665) were categorised into four groups (summer, winter, spring and autumn) according to the date of assistance at the fertility centre. Daily values of temperature, apparent temperature, humidity and atmospheric pressure were provided by the National Weather System and were calculated as the average of the 74 days previous to semen collection (spermatogenic cycle).

Statistical Analysis Used

As appropriate, the results were analysed by analysis of variance/Kruskal-Wallis, Chi-square test, t-test/Mann-Whitney, forward conditional regression model and Spearman/Pearson's correlations.

Results

We detected seasonality effects on sperm count, total sperm count and total motile sperm count, with the highest values in winter and the lowest in summer. Correlation analysis showed that temperature, apparent temperature and humidity negatively correlated with semen parameters, being humidity the most powerful predictive meteorological variable.

Conclusion

Sperm quality is influenced by seasons; increased environmental temperature and humidity negatively affect semen quality.

The Influence of Male Ejaculatory Abstinence Time on Pregnancy Rate, Live Birth Rate and DNA Fragmentation: A Systematic Review

Variation in ejaculatory abstinence time and its influence on semen quality and clinical reproductive outcomes is a growing concern among clinicians and researchers. The WHO (World Health Organization) recommends 2–7 days of abstinence time prior to semen collection for diagnostic purposes; however, the evidence that such an abstinence period leads to better pregnancy outcomes remains unclear. The aim of this systematic review is to evaluate short and long ejaculatory abstinence time in association with pregnancy rate, live birth rate and DNA fragmentation, in order to make a recommendation on an ideal timeframe for ejaculatory abstinence. This review is conducted according to the PRISMA guidelines and registered in PROSPERO (CRD42022379039). The electronic databases PubMed, Embase and Cochrane were searched for eligible studies. The Scottish Intercollegiate Guidelines Network was used for the assessment of the risk of bias across the included studies. Twenty-four studies were included in this systematic review. The included studies confirm that a shorter abstinence time is associated with improved pregnancy rates and live birth rates following assisted reproductive technology compared with longer ejaculatory abstinence times at different cut-off points. Similarly, a lower DNA fragmentation index was reported in semen analyses collected from short abstinence times compared with long abstinence times. However, due to the heterogeneity of the included studies, it is not possible to extract an ideal time of ejaculatory abstinence, but all outcomes improved with shorter ejaculatory abstinence times. This systematic review confirms that short ejaculatory abstinence times, less than those recommended by the WHO for diagnostic purposes, are associated with higher pregnancy and live birth rates and improved DNA fragmentation, when compared to long ejaculatory abstinence times.

The Impact of a Very Short Abstinence Period on Conventional Sperm Parameters and Sperm DNA Fragmentation: A Systematic Review and Meta-Analysis

PURPOSE

In recent years, a growing number of studies have supported the beneficial effects of a very short abstinence period on sperm parameters, especially in patients with oligoasthenozoospermia. However, the results are controversial and no consensus exists regarding whether to request a second semen collection in clinical practice. Therefore, this systematic review and meta-analysis aimed to evaluate the influence of a very short abstinence period (within 4 h) on conventional sperm parameters and sperm DNA fragmentation (SDF) rate.

MATERIALS AND METHODS

The literature search was performed using Scopus and PubMed databases. The meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) guidelines. All eligible studies were selected according to the Population, Intervention, Comparison/Comparator, Outcomes, and Study design (PICOS) model. The quality of evidence of the included studies was analyzed through the Cambridge Quality Checklists. The standardized mean difference (SMD) was used to analyze the outcomes. Cochran-Q and I² statistics were used to evaluate statistical heterogeneity.

RESULTS

We assessed for eligibility 1334 abstracts, and 19 studies were finally included. All 19 articles evaluated the effects of a very short abstinence period on sperm parameters and, among these, 5 articles also evaluated the effects on SDF rate. The quantitative analysis showed a significant reduction in semen volume after a very short abstinence period in both normozoospermic men and patients with oligozoospermia, asthenozoospermia, and/or teratozoospermia (OAT) patients. We found a statistically significant increase in sperm concentration and total and progressive motility in the second ejaculation of patients with OAT. In contrast, the SDF rate decreased significantly in the second ejaculate of OAT patients.

CONCLUSIONS

This is the first systematic review and meta-analysis investigating the impact of a very short abstinence period on sperm parameters and SDF rate. The results suggest that collecting a second consecutive ejaculation after a very short time from the first could represent a simple and useful strategy for obtaining better-quality spermatozoa, especially in patients with abnormal sperm parameters.

Effects of virtual reality erotica on ejaculate quality of sperm donors: a balanced and randomized controlled cross-over within-subjects trial

BACKGROUND

Previous research has shown that the type and duration of erotic material that men have access to during masturbation can influence semen parameters. To our knowledge, the use of virtual reality (VR) headsets to present erotica has not previously been studied. We reasoned that, because VR can provide a more immersive experience to the user, semen parameters of masturbatory ejaculates may be altered.

METHODS

This study had a balanced and randomized controlled cross-over within-subjects design. 504 ejaculates were collected from 63 sperm donors at 4 locations in Denmark. During masturbation each donor was instructed to observe erotic material either on a touch screen monitor or using a VR headset. The order of each pair of within-subject treatments was randomized by the throw of a dice. Anonymized data were analysed with linear mixed and piecewise structural equation models.

RESULTS

Both abstinence period and VR-use influenced the total number of motile spermatozoa ejaculated. For short abstinence periods, VR-use increased the number of motile sperm in the ejaculate. However, the difference between VR and non-VR ejaculates decreased as abstinence period increased such that there was no difference at the mean abstinence period of 58 h. For longer abstinence periods, total motile sperm counts were lower, on average, when men used VR compared to those that did not.

CONCLUSION

The use of VR headsets to view erotica had a strong positive effect on the number of motile sperm in an ejaculate when the donor's abstinence time was short (< 24 h). VR-use could improve the ejaculate quality of men who are asked to provide samples after a short period of abstinence, such as men in infertile partnerships producing samples for ART or cancer patients depositing sperm before treatment.

TRIAL REGISTRATION

Trial retrospectively registered on 13 July 2022 at ClinicalTrials.gov. Identifier: NCT05457764.

Sperm DNA fragmentation in consecutive ejaculates from patients with cancer for sperm cryopreservation

Objective: This prospective consecutive study investigated the variation in sperm DNA fragmentation (SDF) in multiple semen samples from patients with cancer.Methods: Eighty-one patients with various cancers underwent multiple semen collections on 3 consecutive days for sperm cryopreservation prior to cancer treatment. A commercial Halosperm kit was used to measure SDF. Within- and between-subject coefficients of variation were estimated via random-effects analysis of variance to assess the consistency of semen parameters and SDF. Intraclass correlation coefficients (ICCs) were calculated to assess the magnitude of the between-subject component of variance relative to the total variance.Results: The volume of semen in the day-2 and day-3 samples was significantly lower compared with the day-1 sample. Most parameters showed high ICC values, suggesting that within-subject fluctuations were small relative to the between-subject variability. The highest ICC values were identified for the SDF (ICC, 0.68; 95% confidence interval [CI], 0.45–0.84) and semen volume (ICC, 0.67; 95% CI, 0.45–0.84).Conclusion: Our findings showed that repeated ejaculates from patients with cancer had stable SDF levels.

The male infertility evaluation still matters in the era of high efficacy assisted reproductive technology

Today's reproductive endocrinology and infertility providers have many tools at their disposal when it comes to achieving pregnancy. In the setting of highly efficacious assisted reproductive technology, it is natural to assume that male factor infertility can be overcome by acquiring sperm and then bypassing the male evaluation. In this review, we go through guideline statements and a stepwise male factor infertility evaluation to propose that a thorough male evaluation remains important to optimize pregnancy and live birth. The foundation of this parallel evaluation is referral to a reproductive urologist for the optimization of the male partner, for advanced diagnostics and interventions, and for the detection of other underlying male pathology. We also discuss what future developments might have an impact on the workup of the infertile male.

Semen analysis: a workflow for an appropriate assessment of the male fertility status

Infertility is a worldwide problem that affects 9-15% of couples of reproductive age. In about half of the cases, it recognizes, alone or in combination, a male cause. In addition to a reproductive problem, male infertility can result from a systemic disease. Consequently, semen analysis, a fundamental test in the diagnosis of male infertility, represents a useful indicator not only of a man's reproductive capacity but also of his health and lifestyle. Given the key role of semen analysis, only accredited laboratories should perform it and experienced clinicians should be called into play in its interpretation. In this article, we have extensively examined how the macroscopic and microscopic parameters of semen analysis, alone or associated with each other, allow clinicians to orient towards specific diagnoses that can be confirmed by further ad hoc tests. On this basis, we also proposed a diagnostic flowchart focused on the results of the semen analysis.

Association between meteorological variables and semen quality: a retrospective study

Spermatogenesis is a temperature-dependent process, and high summer temperatures have been linked to lower sperm concentration and count. However, reports describing the association between other meteorological variables and semen quality are scarce. This study evaluated the association between semen quality and temperature, humidity, pressure, apparent temperature (AT), temperature-humidity index (THI), simplified wet-bulb global temperature (sWBGT), and sunshine duration. Semen samples were obtained at the Laboratorio de Andrología y Reproducción (LAR, Argentina), from men undergoing routine andrology examination (n=11657) and computer-assisted sperm analysis (n=4705) following WHO 2010 criteria. Meteorological variables readings were obtained from the Sistema Meteorológico Nacional. Sperm quality parameters were negatively affected in summer when compared to winter. Additionally, there was a significant decrease in sperm kinematics between winter and spring. Branch and bound variable selection followed by multiple regression analysis revealed a significant association between semen quality and meteorological variables. Specifically, changes in sunshine duration and humidity reinforced the prognosis of semen quality. Highest/lowest sunshine duration and humidity quantiles resulted in decreased sperm concentration, count, motility, vitality and membrane competence, nuclear maturity, and sperm kinematics associated to highest sunshine duration and lowest humidity. Findings from this report highlight the relevance of environmental studies for predicting alterations in male reproductive health associated to variations in meteorological variables, especially considering the current climate changes around the planet due to global warming and its consequences for human health.

The Effect of Ejaculatory Abstinence Interval on Sperm Parameters and Clinical Outcome of ART. A Systematic Review of the Literature

Since the publication of the first edition of the WHO (World Health Organization) Laboratory Manual for the examination of Human Semen in 1980, the reference values of sperm parameters have been updated on four occasions. Currently and globally, most of the laboratories analyzing semen samples use the latest, 5th edition of the manual that recommends ejaculatory abstinence from two to seven days before producing the sample for examination. While this standardized interval of time facilitates the interpretation of the results and research, no solid evidence exists to support the WHO-recommended abstinence time for a semen analysis in order to optimize clinical outcomes after assisted reproduction. Most of the studies refer to different clinical outcomes, different groups of patients and different editions of the WHO Laboratory Manual, including heterogeneous intervals of abstinence or sperm parameters. The aim of the current systematic review was to evaluate available evidence correlating ejaculatory abstinence time with clinical outcomes and sperm parameters analyzed according to the last edition of the World Health Organization Laboratory Manual reference values in different male populations. The results from the included studies indicate that WHO abstinence recommendations may need revision, given that a shorter ejaculatory abstinence interval appears to be associated with improved sperm parameters, such as sperm DNA fragmentation, progressive motility or morphology, while evidence suggests a potential increase in embryo euploidy rates and pregnancy outcomes.

Short Ejaculatory Abstinence in Normozoospermic Men is Associated with Higher Clinical Pregnancy Rates in Sub-fertile Couples Undergoing Intra-Cytoplasmic Sperm Injection in Assisted Reproductive Technology: A Retrospective Analysis of 1691 Cycles

BACKGROUND

The current WHO abstinence recommendations are ideal only for clinical diagnosis, as in recent years a negative correlation of abstinence duration with good embryo development and clinical pregnancy rate has been seen.

AIM

The aim of the study was to evaluate the impact of variation in abstinence period on fertilization, embryo development potential, pregnancy, and miscarriage rate in sub-fertile couples undergoing assisted reproductive technology (ART) treatment.

SETTING AND DESIGN

A prospective analysis was conducted at a tertiary (level 3) infertility care clinic.

MATERIALS AND METHODS

The study included analysis of 1691 cycles for the patient undergoing ART procedures between September 2017 and August 2019. The influence of ejaculatory abstinence (EA) was investigated based on variation in abstinence length with four groups: Group I - 1 day; Group II - 2-5 days; Group III - 6-7 days; and Group IV - EA length of ≥8 days.

STATISTICAL ANALYSIS

Analysis of variance and Chi-square test were used to calculate P value.

RESULTS

In our primary outcome, we have seen a strong positive correlation of abstinence duration with semen volume, total sperm count, total motile count, and difference between each group was significant. Secondary outcomes showed a significantly higher implantation rate, biochemical pregnancy rate was observed in Group I (1 day) per embryo transfer as compared to longer abstinence groups. This resulted in significantly higher clinical pregnancy rates in Group I 30.0% vs. 25.4% in comparison to longer abstinence groups.

CONCLUSIONS

Our study has shown duration of abstinence is negatively correlated with positive β-human chorionic gonadotropin rate, clinical pregnancy rate, and implantation rate. Lower miscarriage rate was also observed with shorter abstinence duration.

The Use of Pooled Consecutive Ejaculates in Moderate Male Factor Infertility to Increase Intrauterine Insemination Success

Background:

Male factor is a predominant cause of infertility. Success rates of intrauterine insemination(IUI) for male factor depend upon minimum semen parameters such as progressive motility > 30%, strict morphology > 4%, total motile count in the native sample (TMSC) >5 million and inseminating motile count (IMC) > 5 million. Couples with parameters lesser than these are usually advised IVF-ICSI. In developing countries, affordability for IVF is an important deterrent to its widespread utilisation.

Aims:

To evaluate pregnancy rates after the use of a pooled consecutive ejaculate in infertile men with semen parameters of < 5 million TMSC, and to compare with pregnancy rates achieved among couples with semen parameters > 5 million TMSC after processing of a single ejaculate.

Settings and Design:

Private infertility practice. Retrospective study from Oct 2012 to June 2019.

Methods and Materials:

All consecutive patients (n=1979) who underwent IUI in the given study period were included. Patients undergoing donor sperm insemination and low IMC (<1 mill) were excluded from the study. The study group (n=128) included patients in whom the total motile sperm count (TMSC) of the native sample was < 5 million. The control group (n=1851) included patients with normal semen parameters. All participants of the study group with TMSC < 5 million were asked to give a second ejaculate within an hour or two of producing the first. The pooled consecutive ejaculates were used for sample processing and insemination. The primary outcome measure was clinical pregnancy rate. The secondary outcome measures were semen quality of the second ejaculate, TMSC and IMC of both groups.

Statistical Analysis:

Quantitative parameters were compared using Independent sample t-test and Mann Whitney u test. Multivariate binary logistic regression analysis was performed to test the association between the explanatory variables and outcome variable. P value < 0.05 was considered statistically significant.

Results:

6.47% (128/1979) of men were required to give a consecutive ejaculate. The initial ejaculate had significantly higher volume (2ml vs 1 ml; P < 0.001); but lower concentration (8 million/ml vs 19 million/ml; P <0.001) and lower progressive motility (25% vs 35%; P <0.001) in comparison with the second. The final IMC of the pooled ejaculate was 9.01 million vs 21.6 million in the control group (P<0.001). The clinical pregnancy rate was comparable between the control group and the consecutive ejaculate group (15.4% vs 15.63%; P =0.94).

Conclusion:

Consecutive semen samples produced immediately after the first have significantly lower volume but higher sperm count and progressive motility. In couples with moderate male factor infertility with semen parameters inadequate for IUI, pooled consecutive ejaculates yield higher inseminating motile counts which enhance IUI success rates.

Three hour abstinence as a treatment for high sperm DNA fragmentation: a prospective cohort study

PURPOSE

This study sought to compare sperm DNA fragmentation (SDF) in semen specimens after 3 days and then after 3 h of abstinence in men presenting for initial infertility evaluation.

METHODS

A prospective cohort study of 112 men undergoing their first semen analysis as part of an infertility work-up was conducted. All participants presented with 3 days of abstinence for a semen analysis and DNA-fragmentation test. Both tests were repeated on a second sample collected 3 h after the first ejaculation. DNA-fragmentation was evaluated with the halo test by one of two technicians blinded to duration of abstinence. Variables analyzed include ejaculate volume, sperm concentration and motility, smoking status, cannabis use, initial specimen DNA fragmentation, and use of sperm-directed anti-oxidant formulations.

RESULTS

Among all subjects, DNA fragmentation improved in the 3-h abstinence specimen (34.6 ± 19.4% vs. 23.7 ± 16.0%, p = 0.0001). Among subjects with high DNA fragmentation (> 35%) on the initial specimen, 55% improved into the normal range. Semen volume and sperm concentration decreased (3.1 ± 3.3 ml vs. 1.9 ± 0.8 ml, p < 0.01 and 41 ± 39 vs. 32 ± 31 (millions/ml), p = 0.01), while progressive motility tended to increase. Fifty-eight subjects demonstrated ≥ 30% improvement in SDF in the second specimen as compared to the first. Factors found to correlate with > 30% improvement in DNA fragmentation in the 3-h abstinence specimen compared to 3 days were younger age and use of anti-oxidants.

CONCLUSION

High SDF can often be managed with a second ejaculation 3 h after the first in infertile couples, including in males with abnormal semen analyses per the 2010 WHO guide. Apart from SDF levels, changes in sperm quality were not clinically significant in the second specimen and did not increase rates of ICSI. However, a second ejaculation after 3 h probably may reduce the necessity of costly and/or invasive ART strategies.

Semen quality and waiting time to pregnancy explored using association mining

BACKGROUND

Assessment of semen quality is a key pillar in the evaluation of men from infertile couples. Usually, semen parameters are interpreted individually because the interactions between parameters are difficult to account for.

OBJECTIVES

To determine how combinations of classical semen parameters and female partner age were associated with waiting time to pregnancy (TTP).

MATERIALS AND METHODS

Semen results of 500 fertile men, information of TTP, and partner age were used for regressions and to detect breaking points. For a modified Association Rule Mining algorithm, semen parameters were categorized as High, Medium, and Low.

RESULTS

Men ≤32.1 years and women ≤32.9 years had shorter TTP than older. Decreasing TTP was associated with increasing level of individual semen parameters up to threshold values: sperm concentration 46 mill/mL, total sperm count 179 mill, progressive motility 63%, and normal morphology 11.5%. Using association mining, approximately 100 combinations of semen parameters and partner age were associated with TTP. TTP ≤ 1 month often co-occurred with high percentages of progressive motility (≥62%) and morphologically normal spermatozoa (≥10.5%). Furthermore, TTP ≤ 1 did not tend to appear with lower percentages of these two semen parameters or high partner age (≥32 years). However, high percentages of motile or normal spermatozoa could not compensate for sperm concentration ≤42 mill/mL or total sperm count ≤158 mill. The prolonging effect of high partner age could not be compensated for by the man's semen quality.

DISCUSSION AND CONCLUSION

Using association mining, we observed that TTP was best predicted when combinations of semen parameters were accounted for. Sperm counts, motility, and morphology were all important, and no single semen parameter was inferior. Additionally, female age above 32 years had a negative impact on TTP that could not be compensated for by high semen parameters of the man.

One day is better than four days of ejaculatory abstinence for sperm function

According to the World Health Organization guidelines, ejaculatory abstinence (EA) of 2–7 days is recommended for semen analysis. This study aimed to determine how seminal quality may be affected by two EA periods from the same man. Seminal samples from 65 men were evaluated by conventional semen analysis and qualitative characteristics after 1 and 4 days of EA (two samples/man). The semen was qualitatively analyzed by examining oxidative activity (intracellular and seminal plasma), sperm function (acrosome integrity, mitochondrial activity, and nuclear DNA integrity), and epididymal function. As expected, samples collected after 1 day of EA showed a decrease in volume and sperm total number compared to samples collected after 4 days of EA. The sperm motility of the samples collected after 1 day of EA was better compared to samples collected after 4 days of EA. Oxidative activity measured was lower after 1 day of EA compared with those measured after 4 days of EA. With regards to sperm function, samples collected after 1 day of EA showed an increase in acrosome integrity, mitochondrial activity, and nuclear DNA integrity compared with samples collected after 4 days of EA. Epididymal function showed no difference between the two-time points. Although samples collected after 4 days of EA showed better results for sperm quantity, samples collected after 1 day of EA showed better qualitative results, including motility, oxidative activity, and sperm function. Thus, it can be concluded that sperm storage at the epididymal tail may make spermatozoa more susceptible to oxidative damage.

Profiles of Emerging and Legacy Per-/Polyfluoroalkyl Substances in Matched Serum and Semen Samples: New Implications for Human Semen Quality

BACKGROUND

Epidemiological evidence remains equivocal on the associations between environmentally relevant levels of per-/polyfluoroalkyl substances (PFASs) and human semen quality.

OBJECTIVES

We aimed to test whether the potential effects on semen quality could be better observed when seminal PFAS levels were used as an exposure marker compared with serum PFAS levels.

METHODS

Matched semen and serum samples from 664 adult men were collected from a cross-sectional population in China from 2015 to 2016. Multiple semen parameters were assessed, along with measurement of 16 target PFASs in semen and serum. Partitioning between semen and serum was evaluated by the ratio of matrix-specific PFAS concentrations. Regression model results were expressed as the difference in each semen parameter associated with the per unit increase in the ln-transformed PFAS level after adjusting for confounders.

RESULTS

Perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and emerging chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) were detected at their highest concentrations in both semen and serum, with median concentrations of 0.23, 0.10, and 0.06 ng/mL in semen, respectively, and a semen-to-serum ratio of 1.3:3.1. The between-matrix correlations of these PFAS concentrations were high (R=0.70-0.83). Seminal PFOA, PFOS, and 6:2 Cl-PFESA levels were significantly associated with a lower percentage of progressive sperm and higher percentage of DNA fragmentation (false discovery rate-adjusted p-values of<0.05). Associations between serum PFAS levels and semen parameters were generally statistically weaker, except for DNA stainability, which was more strongly associated with serum-based PFASs than with semen-based PFASs.

CONCLUSIONS

Our results suggest the potential for deleterious effects following exposure to 6:2 Cl-PFESA and other PFASs. Compared with serum PFAS levels, the much clearer association of seminal PFAS levels with semen parameters suggests its advantage in hazard assessment on semen quality, although the potential for confounding might be higher. Exposure measurements in target tissue may be critical in clarifying effects related to PFAS exposure. https://doi.org/10.1289/EHP4431.

Application of qualitative and quantitative uncertainty assessment tools in developing ranges of plausible toxicity values for 2,3,7,8-tetrachlorodibenzo-p-dioxin

Increasing interest in characterizing risk assessment uncertainty is highlighted by recent recommendations from the National Academy of Sciences. In this paper we demonstrate the utility of applying qualitative and quantitative methods for assessing uncertainty to enhance risk-based decision-making for 2,3,7,8-tetrachlorodibenzo-p-dioxin. The approach involved deconstructing the reference dose (RfD) via evaluation of the different assumptions, options, models and methods associated with derivation of the value, culminating in the development of a plausible range of potential values based on such areas of uncertainty. The results demonstrate that overall RfD uncertainty was high based on limitations in the process for selection (e.g., compliance with inclusion criteria related to internal validity of the co-critical studies, consistency with other studies), external validity (e.g., generalizing findings of acute, high-dose exposure scenarios to the general population), and selection and classification of the point of departure using data from the individual studies (e.g., lack of statistical and clinical significance). Building on sensitivity analyses conducted by the US Environmental Protection Agency in 2012, the resulting estimates of RfD values that account for the uncertainties ranged from ~1.5 to 179 pg/kg/day. It is anticipated that the range of RfDs presented herein, along with the characterization of uncertainties, will improve risk assessments of dioxins and provide important information to risk managers, because reliance on a single toxicity value limits the information needed for making decisions and gives a false sense of precision and accuracy.

Techniques used for IUI: is it time for a change?

STUDY QUESTION

Are the guidelines for the technical aspects of IUI (WHO, 2010) still in accordance with the current literature?

SUMMARY ANSWER

In general, the laboratory guidelines of the World Health Organization (WHO) are a suitable protocol, although the evidence is not always conclusive and some changes are advisable.

WHAT IS KNOWN ALREADY

Lack of standardization of the technical procedures required for IUI might result in inter-laboratory variation in pregnancy rates. Most centers still use their own materials and methods even though some guidelines are available.

STUDY DESIGN, SIZE, DURATION

A structural review focusing on the association between pregnancy rates and the procedures of semen collection (e.g. ejaculatory abstinence, collection place), semen processing (e.g. preparation method, temperature during centrifugation/storage), insemination (e.g. timing of IUI, bed rest after IUI) and the equipment used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature search was performed in Medline and the Cochrane library. When no adequate studies of the impact of a parameter on pregnancy results were found, its association with sperm parameters was reviewed.

MAIN RESULTS AND THE ROLE OF CHANCE

For most variables, the literature review revealed a low level of evidence, a limited number of studies and/or an inadequate outcome measure. Moreover, the comparison of procedures (i.e. semen preparation technique, time interval between semen, collection, processing and IUI) revealed no consensus about their results. It was not possible to develop an evidence-based, optimal IUI treatment protocol.

LIMITATIONS, REASONS FOR CAUTION

The included studies exhibited a lack of standardization in inclusion criteria and methods used.

WIDER IMPLICATIONS OF THE FINDINGS

This review emphasizes the need for more knowledge about and standardization of assisted reproduction technologies. Our literature search indicates that some of the recommendations in the laboratory guidelines could be adapted to improve standardization, comfort, quality control and to cut costs.

STUDY FUNDING/COMPETING INTEREST(S)

The Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), Nijmegen, The Netherlands. S.K. and W.N. have no conflicts of interest to disclose. C.B. and A.W. are members of the board of the SKML. With a grant from SKML, L.L. was paid for her time to perform the research and write the publication. D.B. received grants from Merck Serono, Ferring and MSD, outside the submitted work.

REGISTRATION NUMBER

N/A.

Effect of the sexual abstinence period recommended by the World Health Organization on clinical outcomes of fresh embryo transfer cycles with normal ovarian response after intracytoplasmic sperm injection

This study was to investigate whether the sexual abstinence period (SAP) recommended by the World Health Organization (WHO) affects clinical outcomes. We compared the rate of clinical outcomes between 2-7 and ≥8 days of SAP in first fresh embryo transfer after intracytoplasmic sperm injection (ICSI) in groups of young maternal age (YMA: <38 years) and old maternal age (OMA: ≥38 years). We conducted a retrospective study of 449 first ICSI cycles with a normal ovarian response. SAP was identified before collecting the semen samples. Semen analysis was performed based on the guidelines recommended by WHO (2010). Sperm preparation was made using the swim-up method. Patients' baseline characteristics in the YMA and OMA groups did not differ. The rates of fertilisation, top-quality embryos on day 3, biochemical pregnancy, clinical pregnancy, ongoing pregnancy, abortion and implantation per cycle were not significantly different between 2-7 and ≥8 days of SAP in the YMA or OMA group. In conclusion, SAP beyond the recommended period by WHO was not associated with the rates of a lower fertilisation and pregnancy in human in vitro fertilisation (IVF). We think that a new criterion of SAP for clinical application in human IVF needs to be considered by WHO.

The impact of ejaculatory abstinence on semen analysis parameters: a systematic review

OBJECTIVE

The aim of this study was to evaluate recent publications and determine the impact of ejaculatory abstinence on semen analysis parameters as well as fertility outcomes.

METHODS

This was a systematic review of 28 recent publications. The focus of this study was the impact of abstinence on semen parameters and fertility outcomes in papers published since the year 2000. The specific parameters evaluated were volume, sperm count, motility, morphology, pH, DNA fragmentation rate, viability, and pregnancy or fertilization rates following assisted reproduction.

RESULTS

Twenty-eight recent publications met inclusion criteria. Analysis of publications showed that longer abstinence is associated with increases in semen volume and sperm count. Studies evaluating the effect of abstinence on motility, morphology, and DNA fragmentation rates are contradictory and inconclusive, although a trend appears to exist toward improvements in semen parameters with shorter abstinence. Semen pH was unaffected by abstinence. The majority of publications found no difference in rates of viability with varying abstinence times, although total number of viable sperm increases with increasing abstinence. Some studies evaluating the impact of ejaculatory abstinence on intrauterine insemination (IUI), intracytoplasmic sperm injection (ICSI), and in vitro fertilization (IVF) demonstrated an association between short abstinence and improved outcomes.

CONCLUSIONS

The impact of abstinence on sperm quality is complex. While certain semen parameters improve with longer abstinence, others appear to improve with shorter abstinence. No clear recommendations can be made regarding ideal abstinence due to the conflicting nature of current evidence. Going forward, more research is needed to evaluate the impact of abstinence on pregnancy and fertilization rates.

Anogenital distance and variability in semen parameters

The purpose of this study was to analyze whether the anogenital distance (AGD) was associated with variability in semen parameters. Semen parameters analyzed following the WHO guidelines and sperm DNA fragmentation were evaluated in 160 semen samples obtained over a period of a year from 16 healthy male volunteers. Two types of AGD measurements from the anus to the rear base of the scrotum (AGD_AS) and to the cephalic insertion of the penis (AGD_AP) were taken in each individual. The association between AGDs and semen parameters were studied using three statistical tools: a) general coefficient of variation (CV) and intra-individual coefficient of variation (CV_i), b) general linear models for repeated measures, and c) mixed model fixed effects panel data. Men with shortened AGD_AP have significantly greater intra-individual variability in sperm concentration, total sperm count, and normal sperm morphology. Conversely, greater total sperm motility was observed in men with long AGD_AS. Shortened AGD_AS was associated with less intra-individual variability of total sperm motility (progressive and non-progressive). AGD measurements were associated with the variability in semen parameters. AGD may be useful to determine intra-individual variability in semen parameters.

ABBREVIATIONS

AGD: anogenital distance; AGD_AP: anogenital distance from the anus to the cephalic insertion of the penis; AGD_AS: anogenital distance from the anus to the rear base of the scrotum; AIC: Akaike information criteria; BMI: body mass index; CV: general coefficient of variation; CV_i: intra-individual coefficient of variation; GLM: generalized linear model; PR+NP: total sperm motility.

Revisiting The Relationship between The Ejaculatory Abstinence Period and Semen Characteristics

Variation in the ejaculatory abstinence period suggested by different guidance bodies have resulted in a growing concern among researchers and clinicians over what the precise period of ejaculatory abstinence ought to be for an optimal semen sample. Several studies have thus been undertaken to examine the association between the length of sexual abstinence and semen characteristics. Not all studies, however, have arrived at the same conclusions. This study aims to review all existing literature published during the past few decades pertaining to the influence of ejaculatory abstinence on semen quality. For the purpose of this systematic review, all data related to sexual abstinence duration and seminal parameters were re-analysed to homogenize the current data. Thorough PubMed, MEDLINE and Google Scholar, a literature search was conducted using the keywords "sexual abstinence", "ejaculatory abstinence", "semen", "spermatozoa", "semen analysis", "sperm parameters", "motility", "reactive oxygen species (ROS)" and "DNA fragmentation". After carefully reviewing all the literature, 30 relevant papers, both written in English and published between January 1979 and December 2016, were included in this review. The weight of the evidence suggests that the decline in semen volume and sperm concentration with shorter abstinence periods is accompanied by a substantial improvement in sperm motility characteristics, especially progressive motility and velocity. Nevertheless, available data are insufficient to support definitive conclusions regarding the influence of the ejaculatory abstinence period on advanced semen parameters (ROS, DNA fragmentation and seminal plasma antioxidant capacity) and pregnancy rates. In conclusion, taking all data into account, shortening of the abstinence period may be beneficial to sperm quality. Furthermore, we recommend that the current guidelines regarding the prescribed abstinence period should be revisited.

The Effect of Oral Phosphodiesterase-5 Inhibitors on Sperm Parameters: A Meta-analysis and Systematic Review

OBJECTIVE

To perform a systematic review and meta-analysis to evaluate the effect of phosphodiesterase-5 (PDE5) inhibitors on sperm parameters.

METHODS

A systematic literature search was performed. Mean value and its standard deviation (mean ± standard deviation) were used to perform quantitative analysis. Statistic heterogeneity scores were assessed with the standard Cochran Q test and I2 statistic. All statistical analyses were conducted by RevMan 5.3.

RESULTS

Eleven studies embraced a total of 1317 participants and 19 subgroups or trials were included. Acute administration of PDE5 inhibitors had no effect on semen volume (mean value [MD] = 0.26; 95% confidence interval [CI]: 0.00-0.48) and sperm concentration (MD = 2.04; 95%CI: -2.95 to 7.04). However, the percentage of motile spermatozoa (MD = 7.05; 95%CI: 2.59-11.51), the percentage of total progressive motility (MD = 6.23; 95%CI: 2.43-10.04), and rapid progressive motility (MD = 3.11; 95%CI: 0.23-5.99) were increased after oral PDE5 inhibitors treatment. Interestingly, these significant changes were observed only in infertile men but not in normal patients (MD = 6.89, P < .001 vs MD = 0.67, P = .71; MD = 6.64, P = .001 vs MD = 2.11, P > .05; and MD = 3.89, P = .04 vs MD = 0.92, P = .59, respectively). The percentage of morphologically normal spermatozoa also increased in infertile men (MD = 12.15; 95%CI: 5.16-19.15). Limited evidence showed the linearity, abnormal forms of spermatozoa, as well as reproductive hormones (total testosterone, free testosterone, luteinizing hormone, and follicle-stimulating hormone) did not benefit from PDE5 inhibitors treatment.

CONCLUSION

Oral PDE5 inhibitors treatment could modestly increase the sperm motility and morphology in infertile men.

Considering climate in studies of fertility and reproductive health in poor countries

Understanding the links between climate and fertility and reproductive health outcomes in poor countries is a major ethical and policy imperative. However, doing so will require researchers in population sciences and in earth and climate sciences to merge their expertise. To this end, the dominant theoretical frameworks and readily available geospatial population data used by social scientists provide a starting point for climate and physical scientists to think about the mechanisms that link climate and weather to fertility and reproductive health, and available climate data and analytic strategies can be used to develop research that considers different scales of influence.

Localization patterns of the ganglioside GM1 in human sperm are indicative of male fertility and independent of traditional semen measures

Semen analysis lacks a functional component and best identifies extreme cases of infertility. The ganglioside G_M1 is known to have functional roles during capacitation and acrosome exocytosis. Here, we assessed whether G_M1 localization patterns (Cap‐Score™) correspond with male fertility in different settings: Study 1 involved couples pursuing assisted reproduction in a tertiary care fertility clinic, while Study 2 involved men with known fertility versus those questioning their fertility at a local urology center. In Study 1, we examined various thresholds versus clinical history for 42 patients; 13 had Cap‐Scores ≥39.5%, with 12 of these (92.3%) achieving clinical pregnancy by natural conception or ≤3 intrauterine insemination cycles. Of the 29 patients scoring <39.5%, only six (20.7%) attained clinical pregnancy by natural conception or ≤3 intrauterine insemination cycles. In Study 2, Cap‐Scores were obtained from 76 fertile men (Cohort 1, pregnant partner or recent father) and compared to 122 men seeking fertility assessment (Cohort 2). Cap‐Score values were normally distributed in Cohort 1, with 13.2% having Cap‐Scores more than one standard deviation below the mean (35.3 ± 7.7%). Significantly, more men in Cohort 2 had Cap‐Scores greater than one standard deviation below the normal mean (33.6%; p = 0.001). Minimal/no relationship was found between Cap‐Score and sperm concentration, morphology, or motility. Together, these data demonstrate that Cap‐Score provides novel, clinically relevant insights into sperm function and male fertility that complement traditional semen analysis. Furthermore, the data provide normal reference ranges for fertile men that can help clinicians counsel couples toward the most appropriate fertility treatment.

Quantifying the Sexual Afterglow: The Lingering Benefits of Sex and Their Implications for Pair-Bonded Relationships

Sex presumably facilitates pair bonding, but how do partners remain pair-bonded between sexual acts? Evolutionary perspectives suggest that sexual afterglow serves this purpose. We explored how long sexual satisfaction would remain elevated following sex and predicted that stronger sexual afterglow would characterize more satisfying partnerships. We pooled the data from two independent, longitudinal studies of newlywed couples to examine these issues. Spouses reported their daily sexual activity and sexual satisfaction for 14 days and their marital satisfaction at baseline and 4 or 6 months later. Results demonstrated that sexual satisfaction remained elevated approximately 48 hr after sex, and spouses experiencing a stronger afterglow reported higher levels of marital satisfaction both at baseline and over time. We interpret these findings as evidence that sexual afterglow is a proximal cognitive mechanism through which sex promotes pair bonding.

Predictive value of sperm deoxyribonucleic acid (DNA) fragmentation index in male infertility

Background

Recently, damage to the sperm DNA has been studied as it is associated with reduced fertilization rates, embryo quality, and pregnancy rates, also higher rates of spontaneous miscarriage.

Objective

To develop a diagnostic method in predicting male infertility.

Material and Methods

The design of this study is cross-sectional. Data were retrieved from medical records of Yasmin IVF Clinic Dr. Cipto Mangunkusumo General Hospital and Daya Medika Infertility Clinic from January to December 2015. Subjects were selected by consecutive sampling and divided into two groups: infertile and fertile. Sperm deoxyribonucleic acid fragmentation index (DFI) was determined by sperm chromatin dispersion (SCD) method using Halosperm® Kit.

Results

There were 114 subjects (36 fertile and 78 infertile) selected into this study. We found no significant difference in the age between both of groups. The median value of sperm DFI in infertile group was significantly higher, 29.95 (26.6–34.3)%, compared to 19.90 (15.6–24.4)% of the fertile group, with p < 0.001. Area Under Curve (AUC) of sperm DFI, 0.862 (95% CI 0.783, 0.941), was higher than concentration (AUC 0.744; 95% CI 0.657, 0.831), motility (AUC 0.668; 95% CI 0.572, 0.765), and morphology (AUC 0.718; 95% CI 0.697, 0.864) of the semen analysis. At the cut-off point of 26.1%, the sperm DFI had sensitivity of 80.8% (95% CI; 70.0, 88.5), specificity of 86.1% (95% CI; 69.7, 94.8), positive predictive value (PPV) of 92.6% (95% CI; 83.0, 97.3), negative predictive value (NPV) of 67.4% (95% CI; 51.9, 80.0), positive likelihood ratio (PLR) of 12.6 (95% CI; 5.4, 29.4), and negative likelihood ratio (NLR) of 0.48 (95% CI 0.31, 0.75). Sperm DFI of ≥26.1% had prevalence ratio of 2.84 (95% CI 1.86, 4.33) for the occurrence of male infertility.

Conclusion

There was significant difference between the median value of sperm DFI of infertile men and fertile men. Compared to semen analysis, sperm DFI at cut-off point of 26.1% has a higher diagnostic value (AUC).

Environmental factors contributed to circannual rhythm of semen quality

We investigated whether human semen parameters present circannual rhythm or not, and whether environmental factors exert on semen quality. This retrospective study used data of patients mainly from Reproductive Medicine Center and Urology and Andrology Clinic of a general hospital in China. Sperm concentration and motility were measured by computer aided sperm analysis (CASA). Sperm morphology was scored based on the strict criteria (WHO, 2010). The Kruskal-Wallis rank test was used to investigate the relationship between semen parameters and season/month. Partial correlation coefficients were used to analyze the relationship between semen parameters and environmental factors. In this study, we found that sperm concentration and total amount per ejaculate were significantly lower in summer and higher in winter. But, sperm progressive motility and motility were significantly higher in spring and summer (from March to June), lower in autumn and winter (September and October). Unexpectedly, normal sperm morphology and mixed agglutination reaction (MAR) positive rate didn't vary along with season or month. Furthermore, temperature was negatively related to sperm concentration and total amount per ejaculate. Precipitation was positively associated with progressive motility and normal sperm morphology, but negatively related to sperm head defect percentage. The length of sunlight was positively related to progressive motility. The Air Quality Index (AQI) was positively associated with semen volume and sperm total amount per ejaculate. These suggest seasonal and monthly variation underlying some semen parameters.

Equivalent seminal characteristics in human and stallion at first and second ejaculated fractions

Sperm quality was assessed in normozoospermic human (n = 10) and Spanish breed stallion (n = 10) after sperm fractionation during ejaculation. The first ejaculated fraction was separated from the second. A third sample was reconstituted using equivalent proportion of both fractions (RAW). Fraction 1, Fraction 2 and RAW semen were incubated for 30 min at 37°C to homogenise the impact of iatrogenic damage between both species. Sperm concentration, motility and sperm DNA damage were assessed in each fraction and RAW semen. The results showed two important facts: (i) spermatozoa confined at Fraction 1 exhibit superior parameters than those included at Fraction 2 in both species, and (ii) there is a certain level of concordance between species in the proportion of benefit observed when Fraction 1 is compared to RAW semen. Altogether, these results call into question whether the standard practice of whole ejaculate collection can be considered the best strategy when using male gametes for artificial insemination. In fact, the reconstituted RAW semen exhibits poorer semen characteristics than those found in Fraction 1.

Why so many sperm cells? Not only a possible means of mitigating the hazards inherent to human reproduction but also an indicator of an exaptation

Redundancy—the excess of supply over necessity—has recently been proposed for human sperm cells. However, the apparent superfluity of cell numbers may be necessary in order to circumvent the hazards, many of which can be quantified, that can occur during the transition from gametogenesis within the testes to zygosis within the female reproductive tract. Sperm cell numbers are directly related to testicular volume, and it is owing to a redundancy, and the possible exaptation, of this latter parameter that a putative excess of sperm cells is perceived.

Evidence for obtaining a second successive semen sample for intrauterine insemination in selected patients: results from 32 consecutive cases

Objective

The goal of this study was to compare the semen parameters of two successive samples obtained within an interval of less than 60 minutes from patients planning to undergo intrauterine insemination (IUI) whose first samples exhibited low semen quality.

Methods

Thirty-two consecutive patients were enrolled in the study. On the day of IUI, the semen analysis of the samples initially presented by all patients met at least two of the following criteria: sperm concentration <5×10⁶/mL, total sperm count <10×10⁶, progressive sperm motility (a+b) in the native sample <30%, and total motile sperm count (TMSC) <4×10⁶. A successive semen sample was obtained no more than 60 minutes after the first sample.

Results

Compared to the first sample, the second exhibited significantly (p<0.05) improved sperm concentration, TMSC, progressive motility, and vitality. Regarding TMSC, the most critical parameter on the day of IUI, 23 patients (71.8%) improved it, while nine (28.2%) displayed poorer outcomes.

Conclusion

In defined cases, requesting a second successive ejaculate on the day of insemination may result in a high percentage of cases in an improvement of the quality of the sample.

Abstinence Time and Its Impact on Basic and Advanced Semen Parameters

OBJECTIVE

To assess the effect of ejaculatory abstinence (EA) periods on routine and advanced sperm tests.

METHODS

Men with normozoospermia provided semen samples after 1, 2, 5, 7, 9, and 11 days of abstinence. A standard semen analysis was performed on all samples. Each specimen was assessed for levels of reactive oxygen species (ROS) and sperm DNA fragmentation. Comparison was also made by grouping EA periods into short (1 day), recommended by World Health Organization (WHO) (2-7 days), and long (9-11 days).

RESULTS

Semen volume (P < .001), sperm concentration (P < .001), and total sperm count (P < .001) increased significantly with abstinence length. Sperm DNA fragmentation was associated with the length of EA (P < .001). Both 1 and 2 days of EA had the least amount of DNA fragmentation (P < .001). Significant increase was seen in volume, pH, viscosity, total count, total motile sperm, and DNA fragmentation between short and recommended EA (P < .05), and between recommended and long EA (P < .05). Short EA had no detrimental impact on semen characteristics according to the 2010 WHO thresholds.

CONCLUSION

Shortening of EA time is not detrimental to sperm quality in men with normozoospermia and is proposed as a method for reducing sperm DNA fragmentation. This strategy could help optimize sperm quality and the chances of natural and assisted conception. Accurate abstinence time should be considered when managing men with infertility problems with semen analyses even when it is within the recommended range.

Associations between urinary phthalate concentrations and semen quality parameters in a general population

STUDY QUESTION

Are urinary phthalate concentrations associated with altered semen quality parameters among males recruited from the general population?

SUMMARY ANSWER

Urinary levels of metabolites of phthalate diesters are associated with lower total sperm counts, larger sperm head sizes, and higher percentages of morphologically abnormal sperm.

WHAT IS KNOWN ALREADY

High dose experiments in rats implicate phthalates as anti-androgens. Studies involving infertile men seeking care suggest that phthalates influence measures of semen quality raising concern about the implications for men in the general population.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study comprised 501 male partners in couples discontinuing contraception to become pregnant, who were recruited from 16 US counties using population-based sampling frameworks from 2005 to 2009.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Urine and semen samples were obtained at baseline from 473 (94%) men, of whom 378 (80%) men provided a second sample the following month. Urine was analyzed for 14 monoester metabolites of phthalate diesters by high-performance liquid chromatography coupled to tandem mass spectrometry. Semen samples were analyzed for 34 quality parameters categorized as general, motility, morphology, sperm head and sperm chromatin structure.

MAIN RESULTS AND THE ROLE OF CHANCE

Urinary mono-[2-(carboxymethyl) hexyl] phthalate (MCMHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-benzyl phthalate (MBzP), and mono-isononyl phthalate (MNP) were significantly associated with lower total sperm counts and concentrations, larger sperm head sizes, higher proportions of megalo head sperm morphology, and/or other morphological changes. Urinary mono-methyl phthalate (MMP) and mono-cyclohexyl phthalate (MCPP) were significantly associated with lower sperm motility, and urine mono-2-ethylhexyl phthalate (MEHP) was significantly associated with higher sperm motility.

LIMITATIONS, REASONS FOR CAUTION

While adverse associations were observed, the implications of the findings for couple fecundity and fertility remain to be established. Cautious interpretation is needed in light of reliance on a single measurement of phthalate measure and no correction for multiple comparisons.

[Semen analysis in involuntary childlessness. What information does it provide?]

Involuntary childlessness is a common problem. In about 50% of cases, inadequate semen quality plays a relevant role. A semen analysis provides information regarding exocrine function of the male reproductive organs of the testes, epidydimis, seminal vesicles, prostate gland, and vas deferens. These parameters can only be interpreted in conjunction with medical history and physical examination. Then they can be useful to identify relevant disorders or the causes of these disturbances. The fundamental principles for the interpretation of a semen analysis are easily learned and traditionally belong to the field of dermatology. This article explains the variables which are examined in a routine semen analysis as well as the reference values. Furthermore, common causes for deviations from the normal values are discussed to allow decision-making for further diagnostic workup. The interpretation of these values must always take into account the situation of the couple.

A systematic review of recent clinical practice guidelines and best practice statements for the evaluation of the infertile male

PURPOSE

We systematically identified and reviewed the methods and consistency of recommendations of recently developed clinical practice guidelines (CPG) and best practice statements (BPS) on the evaluation of the infertile male.

METHODS

MEDLINE and related engines as well as guidelines' Web sites were searched for CPG and BPS written in English on the general evaluation of male infertility published between January 2008 and April 2015.

RESULTS

Four guidelines were identified, all of which reported to have been recently updated. Systematic review was not consistently used in the BPS despite being reported in the CPG. Only one of them reported having a patient representative in its development team. The CPG issued by the European Association of Urology (EAU) graded some recommendations and related that to levels (but not quality) of evidence. Overall, the BPS issued respectively by the American Urological Association and American Society for Reproductive Medicine concurred with each other, but both differed from the EAU guidelines with regard to methods of collection, extraction and interpretation of data. None of the guidelines incorporated health economics. Important specific limitations of conventional semen analysis results were ignored by all guidelines. Besides variation in the methodological quality, implementation strategies were not reported in two out of four guidelines.

CONCLUSIONS

While the various panels of experts who contributed to the development of the CPG and BPS reviewed should be commended on their tremendous efforts aiming to establish a clinical standard in both the evaluation and management of male infertility, we recognized inconsistencies in the methodology of their synthesis and in the contents of their final recommendations. These discrepancies pose a barrier in the general implementation of these guidelines and may limit their utility in standardizing clinical practice or improving health-related outcomes. Continuous efforts are needed to generate high-quality evidence to allow further development of these important guidelines for the evaluation and management of males suffering from infertility.