检索问题
一个男生一辈子能出多少毫升的精液
要估算一个男性一生中能够产生多少毫升的精液，我们需要考虑以下几个因素：精液的平均体积、频率（例如射精的次数）、以及男性的生育年龄等。
精液的平均体积
根据世界卫生组织（WHO）的研究，正常情况下，男性每次射精的精液体积大约在1.5到5毫升之间。根据文献分析，从健康的男性中获取的数据可以让我们总结一些可用的参考值。例如，一份研究显示，具有生育能力的男性在相关标准下，每次射精的精液体积通常在约3.5毫升左右。考虑到这个数据，我们可以取一个中间值大约为3.5毫升。
射精频率
另一个重要的因素是射精的频率。年轻男性的射精频率通常较高，可能为每周2到3次，甚至更多。但随着年龄的增长，射精的频率通常会降低。为了简化，我们假设一个年轻男性在生育年龄（假设为18到40岁之间）后每周射精3次。接下来的推算如下：
- 每周射精次数：3次
- 每年射精次数 = 3次/周 × 52周/年 = 156次/年
- 在此假设生育年龄持续20年（从18到38岁），那么总射精次数为156次 × 20年 = 3120次。
如果我们使用我们之前提到的平均精液体积3.5毫升，那么：
- 总的精液体积 = 射精次数 × 每次精液体积 = 3120次 × 3.5毫升 = 10920毫升（或约10.9升）的精液。
生命周期的考虑
需要注意的是，男性的生育能力和射精频率会随着年龄的增长而变化。一般来说，男性的生育能力在20多岁到30多岁时达到高峰，在此之后可能会逐渐减少。我们在这里简单化假设，认为在大约22年（从18岁到40岁）的育龄内，男性的射精频率大致稳定。
结论
综上所述，一个男性在其生育生涯内（大约从18岁到40岁）能够产生的大约精液总量为10920毫升，也就是约10.9升。此数据依赖于多个假设，如正常的生育频率和每次射精的精液体积。实际数量会有所差异，这要受到个体生理差异、健康状态、以及生活方式等多种因素的影响。
尤其值得关注的是，某些生活因素（如吸烟、饮酒、饮食习惯、以及环境因素）对精液质量和数量都有潜在的影响. 这应当间接影响到最终精液的总产量。
References
1World Health Organization reference values for human semen characteristics.PubMed
Trevor G Cooper, Elizabeth Noonan, Sigrid von Eckardstein, et al.
Hum Reprod Update. 2010 May-Jun;16(3):231-45. doi: 10.1093/humupd/dmp048. Epub 2009 Nov 24.
BACKGROUND: Semen quality is taken as a surrogate measure of male fecundity in clinical andrology, male fertility, reproductive toxicology, epidemiology and pregnancy risk assessments. Reference intervals for values of semen parameters from a fertile population could provide data from which prognosis of fertility or diagnosis of infertility can be extrapolated. METHODS: Semen samples from over 4500 men in 14 countries on four continents were obtained from retrospective and prospective analyses on fertile men, men of unknown fertility status and men selected as normozoospermic. Men whose partners had a time-to-pregnancy (TTP) of < or =12 months were chosen as individuals to provide reference distributions for semen parameters. Distributions were also generated for a population assumed to represent the general population. RESULTS: The following one-sided lower reference limits, the fifth centiles (with 95th percent confidence intervals), were generated from men whose partners had TTP < or = 12 months: semen volume, 1.5 ml (1.4-1.7); total sperm number, 39 million per ejaculate (33-46); sperm concentration, 15 million per ml (12-16); vitality, 58% live (55-63); progressive motility, 32% (31-34); total (progressive + non-progressive) motility, 40% (38-42); morphologically normal forms, 4.0% (3.0-4.0). Semen quality of the reference population was superior to that of the men from the general population and normozoospermic men. CONCLUSIONS: The data represent sound reference distributions of semen characteristics of fertile men in a number of countries. They provide an appropriate tool in conjunction with clinical data to evaluate a patient's semen quality and prospects for fertility.
2Semen quality and alcohol intake: a systematic review and meta-analysis.PubMed
Elena Ricci, Suha Al Beitawi, Sonia Cipriani, et al.
Reprod Biomed Online. 2017 Jan;34(1):38-47. doi: 10.1016/j.rbmo.2016.09.012. Epub 2016 Oct 18.
Alcohol consumption is widespread in the Western world. Some studies have suggested a negative association between alcohol intake and semen quality although others have not confirmed this. MEDLINE and Embase were searched using 'alcohol intake' OR 'alcohol consumption' OR 'alcohol drinking' OR 'lifestyle' combined with 'semen quality' OR 'sperm quality' OR 'sperm volume' OR 'sperm concentration' OR 'sperm motility' for full-length observational articles, published in English. Reference lists of retrieved articles were searched for other pertinent studies. Main outcome measures were sperm parameters, if provided as means (standard deviation or standard error) or as medians (interquartile range). Fifteen cross-sectional studies were included, with 16,395 men enrolled. Main results showed that alcohol intake has a detrimental effect on semen volume (pooled estimate for no/low alcohol consumption 0.25 ml, 95% CI, 0.07 to 0.42) and normal morphology (1.87%, 95% CI, 0.86 to 2.88%). The difference was more marked when comparing occasional versus daily consumers, rather than never versus occasional, suggesting a moderate consumption did not adversely affect semen parameters. Hence, studies evaluating the effect of changes on semen parameters on the reproductive outcomes are needed in advance of providing recommendations regarding alcohol intake other than the advice to avoid heavy alcohol drinking.
3Semen collection and evaluation.PubMed
Joni L Freshman
Clin Tech Small Anim Pract. 2002 Aug;17(3):104-7. doi: 10.1053/svms.2002.34326.
Conformation showing and a variety of dog sports are increasingly popular. Propagation of an excellent dog requires normal fertility. Semen collection and evaluation are essential skills for small animal practitioners who work with breeders and dog-sport enthusiasts. Semen collection can be performed on most dogs in the clinic setting with minimal standard equipment. Preparation of the collection room and presence of a teaser bitch increase the success of sample collection. Semen evaluation consists of several components. First, gross characteristics and sample volume are recorded. Percentage and quality of motility are evaluated immediately. The concentration of spermatozoa in the sample is determined and multiplied by the total sample volume to determine the total number of sperm in the ejaculate. Morphology of > or = 100 spermatozoa is evaluated and recorded to determine the percent normal spermatozoa Total normal sperm per ejaculate is then calculated. Additional tests are often performed. These include cytology of the second and third fractions, culture of the semen, and measurement of semen alkaline phosphatase. Knowledge of normal parameters for canine semen enables the practitioner to evaluate the results of these tests with confidence.
4COVID-19 and Oncofertility: No SARS-CoV-2 in Semen but Inflammation Seems to Affect Sperm Parameters.PubMed
Laure Chaput, Hanae Pons-Rejraji, Hélène Chabrolles, et al.
J Med Virol. 2024 Dec;96(12):e70070. doi: 10.1002/jmv.70070.
The COVID-19 pandemic, driven by SARS-CoV-2, led authorities to recommend halting assisted reproductive technology programs, focusing instead on fertility preservation, for cancer patients. The presence of SARS-CoV-2 in semen remains controversial. This multicentric prospective cohort study, conducted across 12 university medical centers, aimed to determine if SARS-CoV-2 is present in spermatozoa/seminal plasma in cancer patients by RT-PCR and to assess its impact on standard semen parameters. The levels of cytokines and TNF-α were measured in seminal fluid by ELISA. We enrolled 129 men who underwent sperm cryopreservation between July 7, 2020, and June 30, 2021. The 63 were included and tested for COVID-19 in nasal swab samples by RT-PCR and/or by serology. All patients were asymptomatic on the day of semen collection: 50 were uninfected, 8 had a positive nasal swab (PCR+) and 5 were seropositive. SARS-CoV-2 RNA was not detected in the seminal fluid or spermatozoa. Ejaculate volume was significantly lower in the PCR+ group compared to the uninfected group (median [IQR]: 2.6 mL [1.6-3.4] vs. 4.6 mL [2.6-5.2] p < 0.05). Total and progressive motility were lower in the PCR+ group compared to the seropositive group (32.5% [25.0-45.0] vs. 50% [49.0-55.0] p < 0.05, and 22.5% [10.0; 32.5] vs. 44.5% [40-49] p < 0.05). Higher TNF-α level was observed in the PCR+ group (1.9 pg/mL [0-3.9]) compared to the uninfected group (0 pg/mL [0-0.4]) p < 0.05. Although SARS-CoV-2 was not detected in the sperm samples of cancer patients who were PCR+, the infection appears to impact sperm parameters, likely due to inflammation.
5Association between semen collection time and semen parameters: an observational study.PubMed
Shun Bai, Xian-Chao Dou, Hao-Lin Qi, et al.
Asian J Androl. 2023 May-Jun;25(3):339-344. doi: 10.4103/aja202268.
The process of semen collection plays a key role in the quality of semen specimens. However, the association between semen collection time and semen quality is still unclear. In this study, ejaculates by masturbation from 746 subfertile men or healthy men who underwent semen analysis were examined. The median (interquartile range) semen collection time for all participants was 7.0 (5.0-11.0) min, and the median time taken for semen collection was lower in healthy men than that in subfertile men (6.0 min vs 7.0 min). An increase in the time required to produce semen samples was associated with poorer semen quality. Among those undergoing assisted reproductive technology (ART), the miscarriage rate was positively correlated with the semen collection time. After adjusting for confounders, the highest quartile (Q4) of collection time was negatively associated with semen volume and sperm concentration. A longer time to produce semen samples (Q3 and Q4) was negatively correlated with progressive and total sperm motility. In addition, there was a significant negative linear association between the semen collection time and the sperm morphology. Higher risks of asthenozoospermia (adjusted odds ratio [OR] = 2.06, 95% confidence interval [CI]: 1.31-3.25, P = 0.002) and teratozoospermia (adjusted OR = 1.98, 95% CI: 1.10-3.55, P = 0.02) were observed in Q3 than those in Q1. Our results indicate that a higher risk of abnormal semen parameter values was associated with an increase in time for semen collection, which may be related to male fertility through its association with semen quality.
6Sperm concentration and semen volume increase after smoking cessation in infertile men.PubMed
Deniz Kulaksiz, Tuncay Toprak, Eda Tokat, et al.
Int J Impot Res. 2022 Sep;34(6):614-619. doi: 10.1038/s41443-022-00605-0. Epub 2022 Aug 13.
Smoking has negative reproductive consequences. This study investigated the effect of smoking cessation on the main semen parameters. We included 90 participants who applied to our infertility clinic and smoked at least 20 cigarettes a day for at least 1 year. Of the 90 participants, 48 were in the study group and 42 were in the control group. Semen analysis was performed before and at least 3 months after quitting smoking in the study group. Semen analysis was repeated at baseline and at least 3 months later in the control group. Semen parameters such as volume, sperm concentration, total sperm count, morphology, and motility were evaluated according to the World Health Organization criteria. Patient characteristics as well as the duration of the smoking period, the number of cigarettes smoked per day and the time elapsed since smoking cessation were recorded. The mean age of the participants was 34.69 ± 5.3 years, and the duration of infertility was 34.12 ± 12.1 months (n = 90). The number of cigarettes smoked per day was 30.14 ± 6.69, and the smoking time was 8.31 ± 3.53 years. The average time to quit smoking was 104.2 ± 11.51 days (n = 48). A significant increase in semen volume, sperm concentration and total sperm count was observed 3 months after smoking cessation (2.48 ± 0.79 ml vs. 2.90 ± 0.77 ml, p = 0.002; 18.45 × 10/ml ± 8.56 vs. 22.64 × 10/ml ± 11.69, p = 0.001; 45.04 ± 24.38 × 10 vs. 65.1 ± 34.9 × 10, p < 0.001, respectively). This study showed that smoking cessation had a positive effect on sperm concentration, semen volume, and total sperm count. Although smoking cessation contributed positively to sperm motility and morphology, the difference was not statistically significant.
7Heat stress and ram semen production and preservation: Exploring impacts and effective strategies.PubMed
Anass Ben Moula, Zineb Moussafir, Naima Hamidallah, et al.
J Therm Biol. 2024 Jan;119:103794. doi: 10.1016/j.jtherbio.2024.103794. Epub 2024 Feb 5.
As global warming persists, heat stress (HS) continues to affect animals, particularly those raised in extensive systems such as sheep. As a result, there is a growing body of research investigating the physiological and biological consequences of HS on these animals. Recent studies have specifically examined the effects of climate change, global warming, and HS on gametes. Heat stress has been shown to affect ram semen production, resulting in decreased sperm quality and volume in both fresh and stored samples. This is attributed to the effect of heat on hormone production in the testicles, which is critical for successful spermatogenesis. Such effects can have significant consequences on the fertility of female sheep, which could affect the farmers' revenue. Therefore, farmers and researchers are utilizing various strategies and laboratory techniques to mitigate these negative effects. This review aims to comprehensively evaluate the impact of HS on ram semen production and conservation and analyze the different mitigation strategies at various levels, including management and nutritional interventions. The findings of this review will serve as a critical foundation for the development of targeted interventions and sustainable practices in sheep farming, ensuring resilient and profitable operations in the face of ongoing global climate challenges.
8Age-Related COVID-19 Influence on Male Fertility.PubMed
Anastasiia D Shcherbitskaia, Evgeniia M Komarova, Yulia P Milyutina, et al.
Int J Mol Sci. 2023 Oct 30;24(21):15742. doi: 10.3390/ijms242115742.
The impact of coronavirus on the reproductive health of men attracts the special attention of many researchers. While studies suggest changes in sperm parameters and the possibility of testicular inflammation, further studies are needed to elucidate any potential age-related changes in these findings, which is the purpose of the present study. The semen quality parameters, cytokine concentration, and markers of the pro- and antioxidant system were assessed in 60 men five to seven months after the coronavirus infection and in 77 controls (without a history of coronavirus infection). Additionally, participants were divided into two age groups: less than 35 years and 35 years or older. Notably increased round cell count in ejaculate and reduced sperm hyaluronan binding ability were observed among post-infection patients younger than 35 years. In the same group, a decline in seminal plasma zinc levels and nitrotyrosine in the cell fraction was found. In men over 35 years of age, Coronavirus Disease 2019 (COVID-19) led to increased sperm DNA fragmentation, a decrease in the total antioxidant capacity, and an elevation in the levels of interleukin-1β and interleukin-10. The concentration of interleukin-1β decreased over time following recovery in all affected patients. The data obtained suggest the potential adverse impact of the coronavirus infection on male reproductive health; however, these effects appear to be age-dependent.
9Ostrich ejaculate characteristics and male libido around equinox and solstice dates.PubMed
P T Muvhali, M Bonato, I A Malecki, et al.
Trop Anim Health Prod. 2020 Sep;52(5):2609-2619. doi: 10.1007/s11250-020-02299-2. Epub 2020 May 25.
The study evaluated the effect of time of the year in which changes in photoperiod occurs on ostrich semen characteristics and male libido. Semen was collected for 5 days before, on and 5 days after winter solstice (21 June 2016), spring equinox (22 September 2016), summer solstice (21 December 2016) and autumn equinox (20 March 2017) in the southern hemisphere. Semen was collected from 10 South African Black ostrich males (average age ± standard deviation; 4.5 ± 2.27 years) using the dummy female. Semen volume, sperm concentration, total sperm per ejaculate, sperm motility traits, percentage of normal sperm, head and tail abnormalities and percentage of affected sperm in the hypo-osmotic swelling test (HOS) were evaluated. Male libido defined as the willingness of males to mount the dummy female was also recorded. Semen samples collected around summer solstice, spring and autumn equinox were higher in sperm concentration and sperm output compared with winter solstice (P < 0.05). Study periods did not influence semen volume, sperm motility traits, the percentage of normal sperm, head abnormalities and HOS. Tail abnormalities were higher around winter solstice than around spring equinox (P < 0.05). Male libido and the success of semen collection were significantly higher around spring equinox (P < 0.05). Changes in photoperiod in the southern hemisphere do not affect semen production in ostriches. However, high sperm output and male libido around spring equinox and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.
10Bariatric Surgery Does Not Improve Semen Quality: Evidence from a Meta-analysis.PubMed
Zhiguang Gao, Yuzhi Liang, Sen Yang, et al.
Obes Surg. 2022 Apr;32(4):1341-1350. doi: 10.1007/s11695-022-05901-8. Epub 2022 Feb 10.
The meta-analysis aimed to explore the possible relationship between bariatric surgery and semen quality. PubMed, EMBASE, and CENTRAL were searched from database inception through October 28, 2021. Articles were eligible for inclusion if they evaluated the impact pre- and post-bariatric surgery on semen parameters. A total of 9 studies with 218 patients were found. The mean preoperative age distribution of the patients included centralized from 18 to 50 years, and the mean pre-op BMI ranged from 36.7 to 70.5 kg/m. The follow-up period ranged from 6 to 24 months. The results revealed that bariatric surgery had no significant effect on sperm volume, concentration, total count, morphology, total motility, progressive motility, viability, semen pH, and semen leukocytes. Bariatric surgery does not improve semen quality in obese males.