Sperm nuclear DNA fragmentation and its association with semen quality in Greek men

Due to the limitations of conventional semen analysis in predicting a man's fertility potential, sperm DNA fragmentation was recently introduced as a novel marker of sperm quality. This prospective study was undertaken to investigate the associations between conventional seminal parameters and DNA fragmentation in Greek men. A total of 669 subject data were evaluated in two groups, normozoospermic (n = 184) and non‐normozoospermic (n = 485), according to the WHO 2010 (WHO Laboratory Manual for the Examination and Processing of Human Semen, 5th edn. World Health Organization), reference limits. For all the subjects, semen volume, sperm concentration, total count, rapid and total progressive motility and morphology were recorded following the WHO 2010 methods and DNA fragmentation was assessed by the sperm chromatin dispersion assay. An inverse correlation was established between DNA fragmentation and all conventional seminal parameters except semen volume in men with seminal profiles below the reference limits, with statistical significance for rapid and total progressive motility. Normozoospermic men exhibited lower levels of DNA fragmentation than their non‐normozoospermic counterparts, even though the values were not always below 30%. DNA fragmentation testing and traditional semen analysis should therefore be considered as complementary diagnostic tools in a comprehensive evaluation of male infertility.     

Evaluation of reference values of standard semen parameters in fertile Egyptian men

The reference values of human semen, published in the WHO's latest edition in 2010, were lower than those previously reported. The objective of this study was to evaluate reference values of standard semen parameters in fertile Egyptian men. This cross‐sectional study included 240 fertile men. Men were considered fertile when their wives had recent spontaneous pregnancies with time to pregnancy (TTP) ≤12 months. The mean age of fertile men was 33.8 ± 0.5 years (range 20–55 years). The 5th percentiles (95% confidence interval) of macroscopic semen parameters were 1.5 ml for volume and 7.2 for pH. The 5th percentiles of microscopic parameters were 15 million/ml for sperm concentration, 30 million per ejaculate for total sperm count, 50% for total motility, 40% for progressive motility, 62% for vitality, 4% for normal sperm forms and 0.1 million/ml for seminal leucocyte counts. In conclusion , fertile Egyptian men had higher reference values of sperm total motility, progressive motility and vitality, and lower reference values for total sperm counts as compared to those determined by the latest edition of the WHO laboratory manual in 2010. Other semen parameters were identical to those defined by the WHO 2010 manual.     

A randomised trial comparing conventional semen parameters,sperm DNA fragmentation levels and satisfaction levels between semen collection at home and at the clinic

The aim of the randomised trial was to compare conventional semen parameters, sperm DNA fragmentation levels and satisfaction levels between semen samples collected at home and at the clinic. We recruited 110 men with a history of infertility for at least 1 year from the outpatient andrology clinic. Each man collected two semen samples, one at home and one at the clinic. Men were randomly assigned into the home first (n = 55) or clinic first (n = 55) groups. The primary outcome was sperm concentration. There was no significant difference in sperm concentration, sperm DNA fragmentation levels or other conventional semen parameters between home first and clinic first samples (p > .05), while satisfaction levels were significantly higher for home first samples (p < .01). Consistent results were obtained when comparing home-collected and clinic-collected samples within individuals. Men can be offered the option to collect semen samples at home for examination or assisted reproduction without compromising semen quality, especially for those with difficulty in producing semen samples at the clinic.     

上海地区正常生育力男性精液参考值初探

目的:回顾分析上海地区志愿捐精者与正常生育力男性精液分析各项主要参数的分布特征,比较两组男性精液质量的差别,探讨上海地区男性精液参数的正常参考值下限。方法:2010年10月至2011年7月上海市人类精子库招募正常生育力男性41例,健康捐精者100例,按《世界卫生组织人类精液检查与处理实验室手册》(第5版)进行精液常规检测,评估精液体积、精子浓度、前向运动(PR)精子百分率、精子总数和PR精子总数的均值,标准差,并进行t检验。同时统计正常生育力组上述各参数的分布,得出精液特征参数的正常参考值下限。结果:健康捐精组与正常生育力组精液常规各项主要参数(精液体积、精子浓度、PR精子百分率、精子总数、PR精子总数)间差异无统计学意义(P<0.05)。上海地区正常生育力男性精液参考值下限(P<0.05)为:浓度≥27.3×106/ml、PR≥8.1%、体积≥0.82 ml、精子总数≥44.73×106/1次射精、PR精子总数≥24.68×106/1次射精。结论:在评估男性生育力时,精子总数和PR精子总数可能是比精子浓度、精液体积和PR精子百分数更具参考价值的评价指标。     

Circannual variation in human semen parameters

The aim of the present study was to determine whether there were significant monthly variations in the semen parameters (i.e. volume, sperm count, total sperm count, motile and normal sperm count) of men living in a Mediterranean climate area. A total of 10 877 semen analysis results were included. Semen samples were obtained as a part of an initial screening of male partners from couples with infertility problems who were attending our laboratory from 1970 to 2000. Log transformation and cubic root transformation were used to test the sample distribution. Statistical significance was adjusted by year of examination, patient's age and sexual abstinence period by performing covariance analyses. Differences between months were assessed with the Bonferroni post-hoc test. There was an increase in March and a decrease in September in the adjusted mean sperm count (p < 0.0005), total sperm count (p < 0.0005), motile sperm count (p=0.01) and normal sperm count (p=0.002). There were no variations in semen volume in the study period. Monthly changes in semen quality are confirmed in this population.     

Do seasonal variations in ambient temperature,humidity and daylight duration affect semen parameters? A retrospective analysis over eight years

We aimed to evaluate the possible effects of seasonal variation on semen parameters. We retrospectively analysed the data of 6,116 semen samples collected at a university hospital for eight years. The past ambient temperature, relative humidity and daylight duration records, and birth registry of the province were obtained to examine the relationship of seasonal changes in semen parameters with annual birth rates and environmental factors. The mean age was 33.03 ± 6.86 years. We found a significant difference between months for sperm concentration (p < .0001), total sperm count (p < .0001), progressively motile sperm count (p < .0001) and normal sperm morphology (p = .028). The sperm concentration and total count were significantly lower in July and August compared with December, May and June. The progressively motile sperm count in October was 23.6% less than the value of May. The temperature and temperature–humidity index were negatively correlated with semen parameters. The highest number of births was in the summer. However, no correlation was present between deliveries and the semen concentration regarding months (r_s = 0.199, p = .083). In conclusion, we observed significant seasonal and monthly differences in sperm concentration, sperm count and progressively motile sperm count. Increased ambient temperature due to seasonal changes may be a detrimental factor for semen parameters.     

Diagnostic value of routine semen analysis in clinical andrology

Infertility is a major health issue affecting over 48.5 million couples around the world, with the male factor accounting for about 50% of the cases. The conventional semen analysis recommended by the World Health Organization (WHO) is the cornerstone in the evaluation of male fertility status. It includes macroscopic and microscopic evaluation of the ejaculate, which reflects the production of spermatozoa in the testes, the patency of the duct system and the glandular secretory activity. Evaluation of seminal fructose, sperm vitality and leucocytes (Endtz test) are useful adjuncts to semen analysis that provide information on specific clinical conditions. Though several computer-assisted sperm analysis (CASA) systems have been developed, conventional methods for semen analysis are still widely accepted in clinical practice. This review summarises the conventional techniques used in routine semen analysis and their diagnostic value in clinical andrology.     

Effects of microsurgical varicocelectomy on semen analysis and sperm function tests in patients with different grades of varicocele: Role of sperm functional tests in evaluation of treatments outcome

It seems that varicocele play a role in male infertility, as such, their prevalence increases from 15% in the normal population to 80% in secondary infertility subjects. Varicoceles may have negative effects on semen quality. Our goal was to assess the effects of microsurgical varicocelectomy on semen analysis and sperm functional tests in men with different grades of varicoceles. Thirty infertile men with different grades of varicoceles (grades 1 to 3) were enrolled in our study. Semen quality was assessed by semen analysis according to the WHO guideline (WHO, 1999) and four different sperm functional tests (aniline blue, toluidine blue, chromomycin A3 and TUNEL test) were carried out before and 3 months after microsurgical varicocelectomy (M‐varicocelectomy). When considered all three grades together, we showed that M‐varicocelectomy had statistically significant effects on all four types of sperm functional tests (p value<0.05). It also had positive effects on conventional semen parameters, although the effects were not statistically significant for some parameters (for example sperm count). When analysed separately (based on varicocele grades) the surgery, although caused improvements in semen quality, but may have more statistically significant effects on patients with varicocele of higher grade. In addition, in varicocele of lower grade (for example grade 2), sperm function test may be a better predictor of surgical success than the conventional semen analysis. Thus, we show that not only M‐varicocelectomy has significant positive effect on semen quality but also if sperm functional tests become more affordable in the future, because they yield more precise results, their use in daily practice may increase significantly in patients with varicoceles.     

Oestrogen receptor alpha gene polymorphisms relationship with semen variables in infertile men

This study aimed to assess the association of oestrogen receptor alpha (ER‐α) gene polymorphisms and semen variables in infertile oligoasthenoteratozoospermic (OAT) men. In all, 141 men were grouped into fertile men (n = 60) and infertile OAT men (n = 81). They were subjected to assessment of semen analysis, acrosin activity, serum reproductive hormones and genotyping of ER‐α gene. Frequencies of p and x alleles in ER‐α gene PvuII and XbaI polymorphisms were more prevalent among fertile men compared with infertile OAT men. Presence of P and X alleles was associated with increased incidence of male infertility for genotypes PP, XX compared with genotypes pp and xx (OR = 2.8; 95% CI: 2.36–6.97; P = 0.001 and OR = 4.1, 95% CI: 1.49–11.39; P = 0.001, respectively). The mean of semen variables and sperm acrosin activity were significantly higher in cases associated with pp than PP and in xx than XX genotypes of ER‐α gene. Mean levels of all serum reproductive hormones demonstrated nonsignificant differences in different ER‐α genotypes except oestrogen that was elevated in PP and XX ER‐α gene genotypes. It is concluded that as oestrogen is concerned in male gamete maturation, ER‐α gene polymorphisms might play a role in the pathophysiology of male infertility.     

Impaired semen parameters in patients with confirmed SARS-CoV-2 infection: A prospective cohort study

In this prospective study, we investigated the impact of SARS-CoV-2 infection on semen parameters in a cohort of men who had recently recovered from COVID-19. A total of 24 men who had recently recovered from mild COVID-19 were included in the study. Their semen parameters were normal before COVID-19 according to the World Health Organization 2010 reference values. Semen samples were collected from these participants in the recovery phases of COVID-19. To determine the effect of SARS-CoV-2 infection on semen parameters, the patients' pre-COVID-19 and post-COVID-19 semen analyses were compared. The mean age of the participants was 34.7 ± 6.4 years. The median interval between the positive nasopharyngeal swab test and obtaining semen samples was 111.5 (158) days. There was no significant difference in semen parameters before and after COVID-19 in terms of semen volume (p = .56), sperm concentration (p = .06), and progressive motility (p = .14). Total motility (p = .01) and total motile sperm count (p = .02) decreased significantly after SARS-CoV-2 infection compared to the pre-infection values. This study demonstrated that sperm motility and total motile sperm count were the semen parameters which showed a significant reduction in cases with a history of mild COVID-19.     

Age is a significant predictor of early and late improvement in semen parameters after microsurgical varicocele repair

Accumulating evidence indicates that varicocele repair improves sperm quality. However, longitudinal changes in sperm parameters and predictors of improved semen characteristics after surgery have not been fully investigated. We retrospectively reviewed data from 100 men who underwent microsurgical subinguinal varicocele repair at a single centre. Follow‐up semen examinations were carried out at 3, 6 and 12 months post‐operatively. Logistic regression was used to identify predictors of early (3 months) and late (≥6 months) improvement in semen parameters after varicocele repair. At 3 months post‐operatively, 76.1% of the patients had improved total motile sperm counts, which continued to improve significantly up to 12 months post‐operatively (p = .016). When comparing changes in semen parameters between younger (<37 years) and older (≥37 years) men, post‐operative improvements in sperm concentration and motility were greater among younger men. Multivariate analysis showed that younger age was associated with early (p = .043) and late (p = .010) post‐operative improvement in total motile sperm count. Our findings indicate that early varicocele repair improved semen parameters after surgery.     

Effect of modifiable lifestyle factors and antioxidant treatment on semen parameters of men with severe oligoasthenoteratozoospermia

Severe oligoasthenoteratozoospermia (OAT) refers to impaired count, motility and abnormal sperm morphology of infertile men associated with high chromosomal abnormalities. The objective of the present study was to define a management protocol for severe OAT cases and discover new routes to improve their basic semen parameters. We have applied a therapeutic treatment protocol in a cohort of 210 infertile men diagnosed with extreme severe idiopathic OAT. This therapeutic treatment based on modifying the lifestyle factors combined with antioxidant treatment for 6 months in severe OAT to study its effect on basic semen parameter. Basic semen parameters were assessed before and after applying the therapeutic treatment strategy. Sperm concentration, percentage of total motility and progressive motility were significantly increased after applying the therapeutic treatment (p = .006, p = .001 and p = .001 respectively). On the other hand, abnormal sperm morphology was significantly reduced after therapy (p < .01). In conclusion, the present results suggested that antioxidative supplement in combination with modifying the lifestyle factors in a cumulative treatment period significantly improves the basic semen parameters.     

Regional differences in semen qualities in the Baltic region

Recent prospective studies of male reproductive health have shown differences between several European countries. Our objective was to evaluate the current situation in the two Baltic States Estonia and Lithuania. In 1997-99 we investigated semen parameters, levels of reproductive hormones and general health factors of 196 men from the general population in Lithuania; from Estonia, 79 men from the general population and 118 soldiers were investigated. Adjusted for interlaboratory differences and abstinence period, sperm concentration of Lithuanian and Estonian men from the general populations were shown to be 55 and 67 million/mL, respectively. The Estonian soldiers had the highest sperm concentration, 82 million/mL. The frequencies of morphologically normal spermatozoa were 6.2, 7.7 and 9.6%, respectively. In contrast to the semen qualities, highest Inhibin B levels were detected in the Lithuanians (233 pg/mL) followed by Estonian men from the general population (220 pg/mL) and Estonian soldiers (185 pg/mL). The soldiers had also the lowest level of testosterone and oestradiol. The sperm counts of the Estonian and Lithuanian men investigated here are higher than recently shown for Norwegian, Danish, Estonian and Finnish men. Comparisons should be cautiously drawn as the groups are not completely comparable. Still, even within the Baltic region, geographically close and sharing common recent social history, differences in semen quality and levels of reproductive hormones are apparent.     

Quality assessment of frozen bull semen with the precursor A-kinase anchor protein 4 biomarker

In this study, the quality of frozen bull semen was evaluated with the proAKAP4 level test. Sixty straws of frozen bull semen from various batches (n = 30) belonging to six bulls were used in the current study. The frozen bull semen samples were analysed in terms of proAKAP4 levels, sperm morphology and sperm movement parameters at hour 0 and hour 3 after thawing. The semen samples were divided into three groups according to the proAKAP4 levels: low concentration (<25 ng/10x10⁶ spermatozoa), moderate concentration (25 to 39 ng/10x10⁶ spermatozoa) and high concentration (≥40 ng/10x10⁶ spermatozoa). A positive correlation was found between the proAKAP4 level and total motility (TM₃), progressive motility (PM₃), VSL₃ and VCL₃ values obtained after the third-hour thermoresistance test (p < .05). There was a negative correlation between the percentage of sperm abnormal tail and the proAKAP4 level (p < .01). In addition, it was observed that the semen samples with proAKAP4 concentrations of 25 ng/10⁶ spermatozoa and higher preserved the TM₃ and PM₃ motility characteristics. In conclusion, the proAKAP4 has the potential to become a biomarker protein to evaluate in the quality analysis of frozen-thawed semen.     

Does obesity based on body mass index affect semen quality?—A meta-analysis and systematic review from the general population rather than the infertile population

Whether obesity affects the quality of semen has become the focus of research. However, there are some deficiencies in the past research, because the vast majority of known infertile patients were included in the study samples. Taking infertile men as the research object to analyse the impact of obesity on semen quality, which cannot accurately prove that the impact on semen quality is caused by obesity, because the impact on semen quality may also be caused by other factors. Therefore, we selected ordinary obese men rather than infertile patients to conduct a systematic review and meta-analysis of the effects of obesity on semen parameters. The results showed that obesity had no effect on sperm concentration (SMD: −0.15, 95% CI: −0.32 ~ 0.02, p = .088) and percentage of normal sperm morphology (SMD: −0.17, 95% CI: −0.66 ~ 0.32, p = .487), but decreased semen volume (SMD: −0.32, 95% CI: −0.52 ~ −0.12, p = .002), total sperm number (SMD: −0.77, 95% CI: −1.31 ~ −0.23, p = .005), percentage of forward progression (SMD: −0.95, 95% CI: −1.7 ~ −0.19, p = .014) and percentage of viability (SMD: −0.812, 95% CI: −1.532 ~ −0.093, p = .027). Therefore, obesity affects semen quality to a certain extent, and maintaining normal weight may be one of the effective ways to improve male fertility.     

The Uruguayan semen donor population: A twenty-eight-year retrospective study

Several studies have reported a global decline in seminal quality over the years. The objective of this study was to describe the semen donor population of Uruguay through comparing data of successive samples banked by the same donors and the analysis of their semen and physical characteristics, ancestry origin and educational level. A total of 3,449 ejaculated samples collected from 71 donors, cryobanked between 1989 and March 2017 at Fertilab, were analysed. Results revealed a mean age of 23.90 ± 3.98 years, an average weight of 74.95 ± 1.09 kg and a mean height of 1.78 ± 0.06 m. The majority of the donors trace their origin to Europe (74.65%, 53/71) and 66.19% (47/71) have a level of education higher than secondary school. We observed longitudinal differences in two parameters, that is sperm concentration and semen volume. Sperm concentration declined, while semen volume increased significantly over the 28-year period. The results of the present study are in accordance with that of previous articles that also reported a decline in sperm concentration over time. However, no differences were observed in total sperm number per ejaculate due to the increase in semen volume values, thus reflecting no real changes in sperm production over time.     

正常生育力和精子活力低下不育者精子运动计算机辅助分析

用精子活力分析仪对７３名正常生育力男性射出精子进行了精子动力学指标分析；用上述指标分析了２００例精子活力低下不育男性射出精子动力学指标及各项运动参数间相互关系；用己酮可可碱作用精子活力低下不育男性射出精子，观察精子各项运动参数改变。结果：（１）正常生育力组，前向运动精子在总运动精子中比例与精子活动率间不呈相关性；随精子活动率提高，快速相和慢速相精子分布分别逐渐增加和减少，精子ＶＡＰ、ＶＣＬ、ＶＳＬ、ＢＣＦ、ＡＬＨ增加，ＬＩＮ和ＳＴＲ降低。（２）精子活力低下不育组，随精子活动率下降，主要表现在运动速度下降，与正常组比较，精子前向运动能力和运动速度均有明显下降（Ｐ＜０．０５），但ＬＩＮ和ＳＴＲ不管在组内还是与正常组相比均无明显差别（Ｐ＞０．０５），反映出这种前向运动能力的减低是由速度下降引起，速度分布变化以中速相明显。（３）己酮可可碱能明显提高精子活力低下不育者精子的活动率，前向运动率和精子运动快速相的分布；对精子ＬＩＮ，ＳＴＲ影响不明显。     

Improvement in sperm functional competence through modified low‐dose packaging in French mini straws of bull semen

To achieve the targeted artificial insemination coverage with the current rate of semen production, without affecting the conception rate, it needs to reduce the number of spermatozoa per insemination dose in India as per international practice. Therefore, this study was planned to perform different levels of semen dilution, compare in vitro post‐thaw semen quality and develop a modified low‐dose semen packaging method in French mini straw to minimise semen dilution effect. Sixteen ejaculates were collected from Karan Fries bulls (n = 4). The mean percentage post‐thaw motility, viability, membrane integrity, acrosome integrity, lipid peroxidation and capacitation status were estimated as post‐thaw sperm function assays in semen sample diluted to 20, 15, 10 and 5 million spermatozoa per 0.25 ml and filled in the French mini straw by conventional packaging. No significant (p > .05) difference in post‐thaw sperm quality was observed between 15 and 20 million doses; however, below 15 million sperm quality get reduced. There was no significant difference in post‐thaw semen quality traits between 20 million conventional packaging and 5 million spermatozoa/dose in modified packaging. In conclusions, the modified packaging is a very effective method for low‐dose cryopreservation with acceptable post‐thaw semen quality.     

The impact of body mass index on semen parameters in infertile men

This hospital‐based, prospective study was conducted to evaluate the relationship between body mass index (BMI) and various semen parameters in infertile men. A total of 439 men presented for infertility evaluation were assessed by basic infertility evaluation measures including semen analysis and BMI calculation. The main outcome measure was the relationship between BMI groups [BMI: 18.5–24.9 kg/m² (normal weight), 25–29.9 kg/m² (overweight) and ≥30 kg/m² (obese)] and different semen parameters [volume, concentration, motility and morphology]. The mean BMI was 29.67 ± 5.89. Most of patients (82.91%) were overweight or obese. The 3 BMI groups were comparable in semen parameters (P > 0.05). BMI had a negative correlation with various semen parameters. However, this correlation was significant only with sperm concentration (P = 0.035). We concluded that sperm concentration was the only semen parameter which showed significant reduction with higher BMI in infertile men.