Relationship between age and semen parameters in men with normal sperm concentration: analysis of 6022 semen samples

This study evaluates retrospectively the relationship between age and semen parameters among men with normal sperm concentration. It was based on computerized data and performed in an Academic Fertility and IVF Unit. Six thousand and twenty-two semen samples with sperm concentrations of >or=20 x 10(6) ml(-1) were examined according to WHO criteria and analysed in relation to patients' age. For each age group, mean values +/- SD of semen volume, sperm concentration, percentage of motile spermatozoa, normal morphology, acrosome index, total sperm count/ejaculate, total motile sperm count/ejaculate and sexual abstinence duration were examined. A peak semen volume of 3.51 +/- 1.76 ml(-1) was observed at age >or=30 to <35 years and a lowest volume of 2.21 +/- 1.23 ml(-1) was observed at age >or=55 years (P<0.05). Sperm motility was found to be inversely related to age with peak motility of 44.39 +/- 20.69% at age <25 years and lowest motility of 24.76 +/- 18.27% at age >or=55 years (P<0.05). A reduction of 54% was observed for total motile sperm, between values of 103.34 +/- 107 x 10(6) at age >or=30 to <35 years and 46.68 +/- 53.73 x 10(6) (P<0.05) at age >55 years. A statistically significant and inverse relationship was observed between semen volume, sperm quality and patient age, in spite of prolonged sexual abstinence duration. Top sperm parameters were observed at age >or=30 to <35 years, while the most significant reduction in sperm parameters occurred after the age of 55 years.     

Semen quality changes among 2343 healthy Slovenian men included in an IVF-ET programme from 1983 to 1996

To determine whether semen quality in Slovenians has changed over 14 years (1983-96), we analysed retrospectively the semen of 2343 healthy men with a normal spermiogram, who were partners of women with tubal infertility included in the IVF-ET programme. Age at semen collection, duration of sexual abstinence, semen volume, sperm concentration, total sperm count, percentage of spermatozoa with progressive motility, and normal morphology were determined. Multiple regression analysis was used to assess the changes in sperm characteristics according to the year of semen collection, year of the man's birth and the duration of sexual abstinence. Semen volume, sperm concentration, sperm count and total sperm motility did not change between 1983 and 1996, whereas between 1988 and 1996 rapid progressive sperm motility decreased by 0.95% per year (p < 0.0001). Semen volume, sperm concentration, and sperm count increased with duration of sexual abstinence. After adjustment for the year of semen collection and duration of sexual abstinence, multiple regression analysis showed that sperm concentration decreased by 0.67% per each successive year of birth (p = 0.03). Thus the sperm concentration decreased from 87.6 x 10(6)/mL in men born in the 1940s to 77.3 x 10(6)/mL in those born between 1956 and 1960. After 1960, sperm concentration was found to increase. In 2343 healthy men, no decline in semen quality, except in rapid progressive motility, was observed in the study period. Lower sperm concentration was found among men born between 1950 and 1960. This could be related to worse socio-economic status, stress or negative environmental factors in this time period.     

男性年龄与精子顶体酶活性及精子DNA碎片指数的相关性分析

目的探讨男性年龄与精子顶体酶活性、精子DNA碎片指数(DFI)的相关性。方法选取2016年1~8月在我院生殖医学中心就诊的436例不育症男性患者为研究对象,所有患者均行精液常规检查、精子顶体酶活性检查和(或)精子DFI分析。将患者按年龄分为<30岁、30~39岁、≥40岁3组,分析各组的精液常规、顶体酶活性及精子核DFI的差异及其相关性。结果不同年龄段患者的体重指数(BMI)、禁欲天数、精液量无显著性差异(P>0.05);年龄≥40岁组患者的前向运动精子百分率、活动精子百分率及精子顶体酶活性显著低于<30岁和30~39岁组(P<0.05);≥40岁组患者的精子DFI显著高于<30岁和30~39岁组(P<0.05)。年龄与前向运动精子百分率及活动精子百分率之间呈负相关(P<0.05),但是相关性较弱。精子顶体酶活性与精子正常形态率、前向运动精子百分率、非前向运动精子百分率、活动精子百分率呈正相关(P<0.05);精子DFI与年龄、禁欲天数、前向运动精子百分率呈正相关(P<0.01),与精液量、精子浓度、活动精子百分率呈负相关(P<0.05);精子顶体酶活性和DFI之间无相关性(P>0.05)。结论年龄增长会导致精液前向运动精子百分率、活动精子百分率、精子顶体酶活性、DFI等参数改变,直接或间接影响男性生育力。说明年龄对男性不育的影响是多方面的,建议有生育需求的大龄(≥40岁)男性尽早进行生育咨询与评估。     

Relationship between sexual abstinence duration and the acrosome index in teratozoospermic semen: analysis of 1800 semen samples

A high acrosome index (percentage of sperm with normal acrosome morphology--cutoff value > or =10%) is known to be associated with an improved fertilization rate in conventional IVF. A retrospective evaluation of the relationship between duration of sexual abstinence and acrosome index among oligozoospermic and normozoospermic semen samples with teratozoospermia was undertaken. A significant (P = 0.001) decrease in the acrosome index was observed among the normozoospermic samples (n = 1264) between the peak value of 10.2 +/- 3.6% on day 2 and 8.5 +/- 4.0% on day 5 of abstinence, while for the oligozoospermic samples (n = 536) the peak value of 8.7 +/- 3.5% was observed on day 1 and the lowest values of 6.8 +/- 3.7% (P = 0.04) on day 5 of abstinence. The results suggest that an optimal acrosome index will be obtained following a short sexual abstinence.     

Antibiotic susceptibility of urogenital microbial profile of infertile men in South‐eastern Nigeria

Male factors are known to contribute significantly to the infertility problem. The urogenital bacteria profile and semen quality were investigated among 160 men attending infertility clinics in South‐eastern Nigeria. Both semen and urine samples were obtained from each subject and analysed according to standard techniques. A total of 16 (10%) had bacterial infection in their semen samples and individuals of older age groups were significantly affected (χ² = 23.18, P < 0.05). Urinary tract infection (UTI) was observed in 30.6% of subjects, with the highest rate occurring among men aged 36–40 years, but the difference was not significant (χ² = 7.62, P > 0.05). A total of 33.8% of the men had semen volume less than 2 ml per ejaculate, 33.8% also recorded total sperm count of <40 × 10⁶ ml^?1, while 36.3% recorded sperm motility <50%. Fifty‐three individuals (33.1%) had suboptimal sperm morphology (<60%), with the men aged 46–50 years old significantly affected (χ² = 13.03, P < 0.05). All the individuals with bacterial infection in semen also had UTI and suboptimal semen parameters. The commonest bacterial isolates were Proteus species, Staphylococcus aureus and Escherichia coli, which were resistant to most of the antibiotics assessed.     

Trends in semen parameters in the northeast of Scotland

The data on trends in semen quality are conflicting and sensitive to geographical variations. Although previous British surveys on semen quality indicate a decline, the northeast of Scotland has never been included in these surveys. This is an area with low out migration rates where andrology services for a population of 500 000 are centralized within a single laboratory, thus providing a unique opportunity to study population-based trends in semen quality over time. We investigated trends in semen parameters between 1994-2005, in a cohort of 4832 men attending for routine semen analysis at the Aberdeen Fertility Centre who had a sperm density of greater than 20 million per mL. The main outcome measures were trends in sperm density, sperm motility and motile density in the first semen sample. Linear regression and time series analysis were used to examine trends over time in the semen parameters. The mean and standard deviation (SD) age of all men (n=5204) in the study was 34(6) years. The median (inter quartile range) for sperm density and motile density for the study population were 61 (40-91) million/mL and 99 (47-181) million. The mean (SD) sperm motility was 49 (19)%. Among 4832 men (with sperm count >20 million per mL), data adjusted for age and period of abstinence showed a decreasing trend for sperm density over time, R2=0.45 (P=.017). There was no such trend in sperm motility and motile density. However, this trend has to be interpreted with caution due to fluctuations in semen parameters, population bias and the retrospective nature of the analysis.     

Erectile function, sexual drive, and ejaculatory function after reconstructive surgery for anterior urethral stricture disease

OBJECTIVE: To evaluate the effect of urethral reconstructive surgery on sexual drive, erectile function and ejaculation. PATIENTS AND METHODS: The study group consisted of 52 men with a median (range) age of 44 (18-79) years who underwent 59 urethral reconstructive procedures for anterior urethral stricture disease between 2001 and 2004. We evaluated sexual functioning using the O'Leary Brief Male Sexual Function Inventory (BMSFI) before and after surgery. RESULTS: The mean (sd) follow-up was 22.3 (14.8) months. The mean BMSFI scores were only statistically significantly different for an improvement in ejaculation after surgery (P = 0.04). When separated by age, only the men aged 50-59 years reported decreased erectile function after surgery (P < 0.001) and only those aged <40-49 years reported an improvement in ejaculatory function (P = 0.05). Men at <1 year after surgery reported lower sexual drive (P = 0.025) and erectile function (P = 0.05) than men with longer periods of recovery. CONCLUSIONS: The BMFSI is useful for evaluating sexual function after urethroplasty. Overall, the men did not report a decline in erectile function or sexual drive after surgery; however, older men might have a higher incidence of erectile dysfunction after surgery. Erectile function might recover with time. Younger men had the most pronounced improvement in ejaculatory function, but further studies are necessary to evaluate the clinical significance of this.     

Semen and sperm reference ranges for men 45 years of age and older

The most widely used reference values for human semen and sperm variables were developed by the World Health Organization (WHO) to help assess the fertility status of men interested in reproduction (typically a younger population). In this retrospective analysis, data from a large population of men aged 45 years or older were analyzed to derive semen and sperm reference ranges for an older population. Baseline semen samples were obtained from 1174 men with no or mild erectile dysfunction (ED) during the screening phase of two clinical trials evaluating the effects of a drug on human spermatogenesis. The median values and 95% reference ranges for 4 measured semen and sperm parameters (semen volume, sperm concentration, sperm motility, and sperm morphology) and 1 derived parameter (total sperm count) were calculated for the population and by age quartile. These references ranges were compared to established WHO reference values. Associations between the semen and sperm parameters and smoking status, alcohol use, and serum hormone concentrations were also analyzed. The mean age was 52.9 years (range: 45-80). Median semen volume, sperm motility, and sperm morphology parameters declined significantly with age. Only 46% of study subjects had baseline values for semen and sperm parameters that met or surpassed all the WHO reference values. This is the first study to statistically derive semen reference ranges from a large population of men aged 45 years or older. The observation that less than half the men in this study met all 4 WHO reference values for measured semen and sperm parameters underscores the need for age-specific reference ranges.     

Poor semen quality from patients with malignancies does not rule out sperm banking

Cancer therapy can further impair the already poor semen quality in cancer patients. This study evaluated the prefreeze and postthaw semen quality before treatment of patients with malignancies to examine the rationale for sperm banking for these men. Records of nine patients with different malignant tumors, who had been referred for sperm cryopreservation between 1982 and 1997, were reviewed and the results were compared with those of 50 normal healthy donors. Patients did not differ from donors in age, ejaculate volume, or duration of sexual abstinence. The total motile sperm count (median and interquartile range) was significantly different between patients and donors for prefreeze specimens (P=0.026) and postthaw specimens (P=0.008). Also, the percent motility was significantly lower in the patients as compared with the donors in prefreeze (P=0.035) and postthaw specimens (P=0.005). The percentage change in motility after thawing was also larger for patient samples (−54% versus −47%,P=0.39). Other sperm motion characteristics did not significantly differ between the two groups except for postthaw curvilinear velocity (P=0.01). This study concludes that fresh and frozen–thawed semen from patients with malignant tumors is poor in quality but is still adequate for assisted reproductive techniques. As cancer therapy may further impair semen quality, patients should be offered the chance to bank sperm before undergoing cancer therapy. Received: 25 October 1999 / Accepted: 22 May 2000     

过去25年中国有生育力男性精液参数变化的回顾性研究

目的:分析1980～2005年间我国有生育力男性精液参数的变化状况。方法:通过回顾性研究的方式收集相关数据进行分析。结果:收集了25年来自14个省市的共计5834名有生育力男性的精液参数,控制禁欲时间、总睾丸体积等,并去除年龄参数后统计分析显示,随着样本采集年代的不同1996～2000年组精子密度比1980～1995年组呈现显著下降(P<0.0001),而1996～2000年组以后的10年间没有明显变化(P>0.05);精子活动率变化不受样本采集年代的影响(P>0.05),而是随着研究对象年龄的增加而呈现降低;精子总数与精子密度的变化相似,1996～2000年组以前呈现下降(P<0.05),而此后的10年间没有明显变化(P>0.05)。结论:过去25年间中国有生育力男性精液参数中精子密度和精子总数呈现下降,但自1996年后的10年以来没有明显降低;精子活动率不存在与时间相关的变化。     

Seminal characteristics and sexual behavior in men of different age groups： is there an aging effect？

Aim： To assess the seminal characteristics as well as the sexual behavior of men of various age groups to establish the presence of an aging effect on those characteristics. Methods： Semen samples were collected from men （n = 792） undergoing in vitro fertilization or intrauterine insemination in cases of female factor infertility only. Samples were collected using a seminal collection device at intercourse and evaluated manually according to World Health Organization （WHO） standards. Men were divided into four groups according to their ages： （i） 20-30, （ii） 31-40, （iii） 41-50 and （iv） 51-60 years, and their seminal characteristics and responses to a sexual behavior questionnaire were compared. Results： The data showed statistically significant differences in the seminal characteristics tested, most notably in the sperm concentration, motility, grade of motility, hypo-osmotic swelling and normal sperm morphology. Furthermore, the decline in normal sperm morphology with age was more pronounced when using strict criteria rather than WHO standards. There were also differences in total sperm count, total motile sperm and total functional sperm fraction （assessed by both WHO and strict criteria）. Significant differences were also observed in the sexual behavior patterns in older men in terms of the number of years they have been trying to conceive, sexual frequency and sexual satisfaction. Conclusion： The data clearly illustrate an aging effect on semen characteristics and sexual behavior in men as they age. It is suggested that the aging effect be taken into consideration when proposing normal standard values for semen characteristics in routine semen analysis as outlined by WHO standards.     

不同年龄层次男子的精液特征和性行为:年龄效应

目的:评估不同年龄层次男子的精液特征和性行为,以确认年龄是否对其有影响。方法:女方所致不育夫妇中,取接受体外受精或宫内人工受精的男子(792人)精液作为样本。用精子采集器在性交过程中采集样本,并用 WHO 的标准人工评估精液特征。将这些男子根据年龄分为4组:(i)20-30、(ii)31-40、(iii)41-50和(iv)51-60岁。比较他们的精液特征和填写的性行为反应调查表。结果:数据显示不同年龄层次的男子之间的精液特征,尤其是精子浓度、活力、活力等级、低渗肿胀和正常精子形态,有显著统计差异。用严格标准而不是 WHO 标准评估时,正常精子形态随年龄的下降更显著。精子总量、总活动精子和总功能精子成分(使用 WHO 标准和严格标准评估)也有差异。年龄男子的计划怀孕年份、性行为频率和性交满意度与低龄男子相比也有显著差异。结论:本研究数据明显表明年龄对精液特征和性行为有影响,说明用 WHO 标准进行常规的精液分析以制定正常精液特征标准值时应该考虑年龄影响。     

Have sperm counts deteriorated over the past 20 years in healthy, young Japanese men? Results from the Sapporo area

Changes in semen quality of healthy men is a controversial issue throughout the world. It is suspected that many chemical endocrine disrupters may affect the quality of semen. Although exposure to them may be extensive in Japan, no evidence of changes in semen quality has been reported. In this study, changes in semen volume and sperm counts were analyzed over 20 years in the Sapporo area of Japan. Semen volume and sperm counts were measured in 254 and 457 normal, healthy volunteers who lived in the Sapporo area in 1975-1980 and 1998, respectively. Posters and handbills were used to recruit participants in both studies. Semen samples were collected by masturbation after 3 days or more of abstinence. There was no change in semen volume between 1975-1980 and 1998. Mean sperm counts were 70.9 +/- 47.3 x 10(6)/mL in 1975-1980 and 79.6 +/- 49.3 x 10(6)/mL in 1998. Sperm counts did not decline over about 20 years. No significant correlation between age and sperm counts was recognized in either study. The rates of subjects with oligozoospermia and azoospermia were the same in both studies. In the 1975-1980 study, 34 of 254 (13.4%) participants had a child, and in the 1998 study, 51 of 457 (11.2%) participants had a child. Mean sperm count was significantly (P < .02) lower in the earlier study (66.0 +/- 44.9 x 106/mL) than in the 1998 study (98.7 +/- 60.2 x 10(6)/mL). This is the first reliable report in which changes in sperm counts in Japan were studied. We conclude that there was no evidence of deterioration in sperm counts of normal healthy men who lived in the Sapporo area of Japan over 20 years. However, selection bias in the recruitment of volunteers and the issue of variable abstinence might have affected the results of these studies. Therefore, well-designed prospective studies should be performed in several different regions to extrapolate our results on sperm counts to healthy, young Japanese men in general. Key words: Fertility, endocrine disruptors, seminalysis.     

High levels of lipid peroxidation in semen of diabetic patients

The aim of this study was to evaluate the level of malondialdehyde (MDA) (one of the final products of lipid peroxidation and well-known marker of oxidative stress) in semen of infertile men with type 2 diabetes and to investigate its relationship with their glycaemic control. Forty infertile men with type 2 diabetes were evaluated. The mean ages were 36.5 ± 8.0. Men with diabetes were divided into two groups. Group A (n = 20) with glycated haemoglobin >10% and group B (n = 20) with glycated haemoglobin <7%. A single sample was examined according to the criteria of the World Health Organization (WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction, 1999, Cambridge University Press). MDA was assessed using the thiobarbituric acid method. MDA concentration in semen of group A patients (0.95 ± 0.35 nmol ml(-1)) was significantly higher than in group B patients (0.43 ± 0.13 nmol ml(-1)) (P value < 0.05) and had negative relationship with sperm density (r = -.717; P value < 0.05), total sperm count (r = -.625; P value < 0.05), progressive motility (r = -.489; P value < 0.05) and normal forms (r = -.545; P value < 0.05). Based on these results, it could be concluded that increase in lipid peroxidation in men with diabetes with poor metabolic control was associated with low sperm quality.     

Is varicocelectomy indicated in subfertile men with clinical varicoceles who have asthenospermia or teratospermia and normal sperm density?

OBJECTIVE: Varicocele is the most common treatable cause of male infertility and is associated with progressive decline in testicular function. Varicocelectomy, a commonly performed operation, is indicated in infertile males with varicoceles who have oligospermia, asthenospermia, teratospermia or a combination of these factors. It is not clear if varicocelectomy is indicated if the patients have normal sperm density associated with asthenospermia or teratospermia. METHODS: We reviewed 167 patients with varicocele-associated male infertility over a 7-year period (December 1999-November 2005). Pre- and post-varicocelectomy seminal fluid analyses, assessed using the World Health Organization criteria, were obtained at intervals of 4-6 months. Wilcoxon signed rank tests were used to evaluate for statistical significance and P < or = 0.05 was considered significant. RESULTS: The mean age of the patients and their spouses were 35 and 28 years, respectively. The mean duration of infertility was 3.2 years (range, 1.5-7.5). Oligospermia, teratospermia, asthenospermia, oligospermia, asthenospermia and teratospermia (OAT) syndrome and azoospermia were found preoperatively in 106 (63.5%), 58 (34.7%), 154 (92%), 118 (71%) and 15 (9%) patients, respectively. Overall, significant improvements in semen volume (P < 0.001), sperm density (P < 0.001), sperm motility (P < 0.001) and sperm vitality (P < 0.001) were obtained after varicocelectomy. There was, however, no significant improvement in sperm morphology after varicocelectomy (P = 0.220). When patients with preoperative oligospermia (sperm density, <20 million/mL) were considered separately, varicocelectomy led to significant improvement in all the semen parameters except the sperm morphology (P = 0.183). Conversely, when varicocele patients with a sperm density of > or =20 million/mL (normospermia) associated with asthenospermia and/or teratospermia were considered separately, they did not show significant improvement in any of the semen parameters after varicocelectomy (P > 0.05). In addition, azoospermic patients did not show significant improvement in any of the semen parameters (P > 0.05) CONCLUSION: No significant improvement in semen parameters may be obtained in patients with clinical varicocele and preoperative normospermia. It is possible that only patients with preoperative oligospermia may benefit from varicocelectomy. Larger multi-institutional studies are needed to determine more definitively if asthenospermia or teratospermia in normospermic subfertile males with clinical varicoceles are in fact indications for varicocelectomy.     

精液参数与射精频率的关系

通过对２０名性功能正常的男子（１０例精液正常，１０例少弱精症）连续１周，每天采集精液标本进行观察，探讨了他们的精液参数与射精频率之间的关系。结果表明，正常组的精液容积、１次射精的精子总数逐日下降，于第５天降至原水平５０％左右，以后维持在该水平上下波动，而精子密度并不下降；少弱精组精液容积、精子密度及１次射精的精子总数均显著下降。精子活力和形态在两组中都相对变化不大。     

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.     

LDH-C4 in human seminal plasma and its relationship to testicular function

Lactate dehydrogenase (EC 1.1.1.27) isoenzyme LDH-C4 (LDH-X) has been analyzed quantitatively in semen from men with different fertility status, such as men with pregnant wives, men with primary or secondary infertility, volunteers, men taking salazopyrine and men exposed to very hot baths. LDH-C4 activity per ml or per ejaculate was not related to the fertility status of the men. The situation was different when the LDH-C4/sperm ratio was used as a variable. The median (p50) LDH-C4 activity in semen was (in nanokat/10(8) spermatozoa) 9.4 for samples from men (N = 34) whose wives were in early pregnancy, 24.7 for men (N = 102) with primary infertility and 28.8 for men (N = 18) taking sulphasalazine. The differences in median values between the former group and the latter two groups were highly significant (P less than 0.001). In addition, semen samples from 3 infertile men who took daily hot baths as a habit, had a significantly higher LDH-C4/sperm ratio than samples collected during periods when they did not take hot baths. Semen samples were subdivided according to the number of spermatozoa in the ejaculate after correction for days of abstinence and the size of the testes. There was an inverse correlation between the LDH-C4/sperm ratio and the adjusted sperm count (million per day and per ml testes). Men with an adjusted sperm count of 0.5 or less had a median (p50) LDH-C4 activity of 38 nanokat/10(3) spermatozoa compared to 14.5 in samples from men with an adjusted sperm count of more than 1.0 (P less than 0.001). The LDH-C4/sperm ratio in seminal plasma may therefore serve as an indicator of the function of the seminiferous epithelium, and its assessment may provide a new means for the study of spermatogenesis and male reproduction.     

Study of a group of 484 fertile men Part II: Relation between age (20–59) and semen characteristics

Commonly measured semen variables as well as post-thaw motility have been studied as a function of age in fertile men. The mean age was 34.6 (so = 6.6). No significant change with age was found for the sperm count, semen volume or total number of spermatozoa. Conversely, there were significant differences between age groups for the percentage of normal cells ( P < 0.01) and the percentage of motile forms ( P < 0.01) as well as for the after-thaw motility ( P < 0.001). These three variables rise, reach a maximum level at 30 to 35 years of age and then decrease. These changes are not explained by variations in the length of abstinence.