According to the World Health Organization (WHO) manual, sperm concentration should be measured using an improved Neubauer hemocytometer, while sperm motility should be measured by manual assessment. However, in China, thousands of laboratories do not use the improved Neubauer hemocytometer or method; instead, the Makler counting chamber is one of the most widely used chambers. To study sources of error that could impact the measurement of the apparent concentration and motility of sperm using the Makler counting chamber and to verify its accuracy for clinical application, 67 semen samples from patients attending the Department of Andrology, West China Second University Hospital, Sichuan University (Chengdu, China) between 13 September 2023 and 27 September 2023, were included. Compared with applying the cover glass immediately, delaying the application of the cover glass for 5 s, 10 s, and 30 s resulted in average increases in the sperm concentration of 30.3%, 74.1%, and 107.5%, respectively (all P < 0.0001) and in the progressive motility (PR) of 17.7%, 30.8%, and 39.6%, respectively (all P < 0.0001). However, when the semen specimens were fixed with formaldehyde, a delay in the application of the cover glass for 5 s, 10 s, and 30 s resulted in an average increase in the sperm concentration of 6.7%, 10.8%, and 14.6%, respectively, compared with immediate application of the cover glass. The accumulation of motile sperm due to delays in the application of the cover glass is a significant source of error with the Makler counting chamber and should be avoided.
Humans ; Male ; Sperm Motility/physiology* ; Sperm Count ; Semen Analysis/methods* ; Spermatozoa/physiology* ; Time Factors

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

Recent studies have shown that shorter periods of ejaculatory abstinence may enhance certain sperm parameters, but the molecular mechanisms underlying these improvements are still unclear. This study explored whether reduced abstinence periods could improve semen quality, particularly for use in assisted reproductive technologies (ART). We analyzed semen samples from men with normal sperm counts ( n = 101) and those with low sperm motility or concentration ( n = 53) after 3-7 days of abstinence and then after 1-3 h of abstinence, obtained from the Reproductive & Genetic Hospital of CITIC-Xiangya (Changsha, China). Physiological and biochemical sperm parameters were evaluated, and the dynamics of transfer RNA (tRNA)-derived fragments (tRFs) were analyzed using deep RNA sequencing in five consecutive samples from men with normal sperm counts. Our results revealed significant improvement in sperm motility and a decrease in the DNA fragmentation index after the 1- to 3-h abstinence period. Additionally, we identified 245 differentially expressed tRFs, and the mitogen-activated protein kinase (MAPK) signaling pathway was the most enriched. Further investigations showed significant changes in tRF-Lys-TTT and its target gene mitogen-activated protein kinase kinase 2 ( MAP2K2 ), which indicates a role of tRFs in improving sperm function. These findings provide new insights into how shorter abstinence periods influence sperm quality and suggest that tRFs may serve as biomarkers for male fertility. This research highlights the potential for optimizing ART protocols and improving reproductive outcomes through molecular approaches that target sperm function.
Male ; Humans ; Spermatozoa/metabolism* ; RNA, Transfer/genetics* ; Sperm Motility/genetics* ; Adult ; Semen Analysis ; Sexual Abstinence/physiology* ; Sperm Count ; DNA Fragmentation

This study aimed to investigate the associations between the post-wash total progressively motile sperm count (TPMSC) in the first intrauterine insemination (IUI) cycle and pregnancy outcomes of the second IUI cycle. Data were retrieved from the clinical database at the Reproductive Center of Peking University Third Hospital (Beijing, China) between January 2011 and December 2022. Couples were included in this retrospective cohort study if they had unexplained or mild male factor infertility and were treated with IUI for two consecutive cycles using the same protocol. A total of 8290 couples were included in the analysis. The mean ± standard deviation (s.d.) age of women was 32.0 ± 3.5 years. We categorized groups based on the post-wash TPMSC (×10 6 ) levels in the first IUI cycle: group 1 (0 < TPMSC < 1, n = 1290), group 2 (1 ≤ TPMSC < 2, n = 863), group 3 (2 ≤ TPMSC < 3, n = 800), group 4 (3 ≤ TPMSC < 4, n = 783), group 5 (4 ≤ TPMSC < 5, n = 1541), group 6 (5 ≤ TPMSC < 6, n = 522), group 7 (6 ≤ TPMSC < 7, n = 547), group 8 (7 ≤ TPMSC < 8, n = 175), group 9 (8 ≤ TPMSC < 9, n = 556), group 10 (9 ≤ TPMSC < 10, n = 192), and group 11 (TPMSC ≥ 10), n = 1021). The primary outcome was live birth rate of the second IUI cycle. Live birth rates were 7.9%, 5.8%, 7.6%, 7.4%, 7.3%, 8.4%, 7.5%, 7.4%, 8.8%, 8.9%, and 7.6% in each group, respectively. There were no statistically significant differences in clinical pregnancy rates or live birth rates between any groups and those with the post-wash TPMSC <1 × 10 6 . In an IUI program for unexplained and mild male factor infertility, the post-wash TPMSC in the first IUI cycle was not significantly associated with the live birth rate in the second IUI cycle.
Humans ; Female ; Male ; Pregnancy ; Adult ; Retrospective Studies ; Sperm Count ; Pregnancy Rate ; Sperm Motility/physiology* ; Insemination, Artificial/methods* ; Pregnancy Outcome ; Infertility, Male/therapy* ; Insemination, Artificial, Homologous ; Live Birth

OBJECTIVE: To explore and quantify the association of hot night exposure during the sperm development period (0-90 lag days) with semen quality. METHODS: A total of 6,640 male sperm donors from 6 human sperm banks in China during 2014-2020 were recruited in this multicenter study. Two indices (i.e., hot night excess [HNE] and hot night duration [HND]) were used to estimate the heat intensity and duration during nighttime. Linear mixed models were used to examine the association between hot nights and semen quality parameters. RESULTS: The exposure-response relationship revealed that HNE and HND during 0-90 days before semen collection had a significantly inverse association with sperm motility. Specifically, a 1 °C increase in HNE was associated with decreased sperm progressive motility of 0.0090 (95% confidence interval [ CI]: -0.0147, -0.0033) and decreased total motility of 0.0094 (95% CI: -0.0160, -0.0029). HND was significantly associated with reduced sperm progressive motility and total motility of 0.0021 (95% CI: -0.0040, -0.0003) and 0.0023 (95% CI: -0.0043, -0.0002), respectively. Consistent results were observed at different temperature thresholds on hot nights. CONCLUSION Our findings highlight the need to mitigate nocturnal heat exposure during spermatogenesis to maintain optimal semen quality.
Humans ; Male ; Semen Analysis ; Adult ; Sperm Motility ; Hot Temperature/adverse effects* ; China ; Middle Aged ; Spermatozoa/physiology* ; Young Adult

Animals ; Antigens, Surface/genetics* ; Cell Communication/genetics* ; Copulation/physiology* ; Fallopian Tubes/metabolism* ; Female ; Fertilization/genetics* ; GPI-Linked Proteins/genetics* ; Gene Expression Regulation ; Genes, Reporter ; Green Fluorescent Proteins/metabolism* ; Litter Size ; Luminescent Proteins/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mitochondria/metabolism* ; Reproduction/genetics* ; Signal Transduction ; Sperm Count ; Sperm Motility/genetics* ; Spermatozoa/metabolism* ; Uterus/metabolism*

The novel coronavirus disease (COVID-19) pandemic is emerging as a global health threat and shows a higher risk for men than women. Thus far, the studies on andrological consequences of COVID-19 are limited. To ascertain the consequences of COVID-19 on sperm parameters after recovery, we recruited 41 reproductive-aged male patients who had recovered from COVID-19, and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge. For longitudinal analysis, a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling. Compared with controls who had not suffered from COVID-19, the total sperm count, sperm concentration, and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling, while sperm vitality and morphology were not affected. The total sperm count, sperm concentration, and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined. Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls, no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients. Although it should be interpreted carefully, these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.
Adult ; Asthenozoospermia/virology* ; COVID-19/physiopathology* ; China ; Gonadal Steroid Hormones/blood* ; Humans ; Male ; Progesterone/blood* ; Prolactin/blood* ; SARS-CoV-2 ; Semen/physiology* ; Semen Analysis ; Sperm Count ; Sperm Motility ; Spermatozoa/physiology* ; Time Factors

Dysfunctional sperm maturation is the primary reason for the poor sperm motility and morphology in infertile men. Spermatozoa from infertile men were fractioned on three-layer density gradient (80%, 60%, and 40%). Fraction 1 (F1) refers to the least mature stage having the lowest density, whereas the fraction 4 (F4) includes the most dense and morphologically mature motile spermatozoa. Fraction 2 (F2) and fraction 3 (F3) represent the intermediate stages. Proteins were extracted and separated by 1-dimensional gel. Bands were digested with trypsin and analyzed on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Functional annotations of proteins were obtained using bioinformatics tools and pathway databases. A total of 1585 proteins were detected in the four fractions of spermatozoa. A dysregulated protein turnover and protein folding may lead to accumulation of defective proteins or proteins that otherwise would have been eliminated during the process of maturation, resulting in the impairment of sperm function. Aberrant chaperone expression may be a major contributing factor to the defective sperm function. Androgen receptor was predicted as a transcription regulator in one of the networks and the affected pathways were chaperone-mediated stress response, proteosomal pathway, and sperm function. The downregulation of key pathways and proteins which compromises the fertilizing potential of spermatozoa may provide insight into the mechanisms that lead to male infertility.
Adult ; Cell Shape/physiology* ; Humans ; Infertility, Male/metabolism* ; Male ; Proteome/metabolism* ; Proteomics ; Signal Transduction/physiology* ; Sperm Motility/physiology* ; Spermatozoa/metabolism* ; Tandem Mass Spectrometry

Vitamin D deficiency is a common health issue around the world. We therefore evaluated the associations of semen quality with both serum and seminal plasma vitamin D levels and studied the mechanisms underlying these by incubating spermatozoa with 1,25(OH)₂D In vitro. Two hundred and twenty-two men were included in our study. Vitamin D was detected using an electrochemiluminescence method. Spermatozoa used for In vitro experiments were isolated by density gradient centrifugation. Positive relationships of serum 25(OH)D with semen volume and seminal plasma fructose were identified. Seminal plasma 25(OH)D level showed no relationship with serum 25(OH)D level, while it was inversely associated with sperm concentration and positively correlated with semen volume and sperm kinetic values. In vitro, sperm kinetic parameters increased after incubation with 1,25(OH)₂D, especially upon incubation for 30 min with it at a concentration of 0.1 nmol l^-1. Under these incubation conditions, the upward migration of spermatozoa increased remarkably with increasing adenosine triphosphate (ATP) concentration. The concentration of cyclic adenosine monophosphate (cAMP) and the activity of protein kinase A (PKA) were both elevated, and the PKA inhibitor, N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H89) reversed the increase of ATP production. The concentrations of cytoplasmic calcium ions and nicotinamide adenine dinucleotide (NADH) were both enhanced, while mitochondrial calcium uniporter (MCU) inhibitor, Ruthenium 360 (Ru360) did not reverse the increase of ATP production. Therefore, seminal plasma vitamin D may be involved in regulating sperm motility, and 1,25(OH)₂D may enhance sperm motility by promoting the synthesis of ATP both through the cAMP/PKA pathway and the increase in intracellular calcium ions.
Adenosine Triphosphate/metabolism* ; Adult ; Calcium/metabolism* ; Cyclic AMP/metabolism* ; Cyclic AMP-Dependent Protein Kinases/metabolism* ; Humans ; Male ; Semen/metabolism* ; Semen Analysis ; Signal Transduction/physiology* ; Sperm Motility/physiology* ; Spermatozoa/metabolism* ; Vitamin D/pharmacology* ; Vitamin D Deficiency/blood* ; Wit and Humor as Topic ; Young Adult

ObjectiveTo study the effect of Erxian Decoction (EXD) on oligospermia (OS) induced by cyclophosphamide in mice.

METHODSEighty 6-week-old male Kunming mice were randomly divided into five groups of equal number, normal control, OS model control, and low-, medium- and high-dose EXD, the former two groups treated intragastrically with normal saline and the latter three with EXD at 3, 6 and 12 g per kg of the body weight qd for 30 days. From the 21st day of administration, the mice of the normal control group were injected intraperitoneally with saline and those of the other four groups with cyclophosphamide at 80 mg per kg of the body weight qd for 5 consecutive days. At 24 hours after the last gavage, the bilateral epididymides of the mice were collected and sperm suspension prepared for determination of the sperm count and motility, and the bilateral testes were harvested for histomorphological observation and measurement of the concentrations of superoxide dismutase (SOD), malondialdehyde (MAD) and glutathione (GSH) in the testis tissue.

RESULTSCompared with the normal controls, the mice of the OS model control group showed significant decreases in epididymal sperm concentration (［9.31 ± 1.32］ vs ［3.32 ± 1.13］×107/ml, P <0.01) and motility (［44.75 ± 8.12］% vs ［25.95 ± 11.41］， P<0.01) and the concentrations of SOD (［37.27 ± 0.99］ vs ［14.23 ± 1.99］ U/mg prot, P <0.01) and GSH (［101.55 ± 8.74］ vs ［58.77 ± 8.93］ μmol/L, P <0.01) but an obvious increase in the MDA level (［2.21 ± 0.65］ vs ［2.61 ± 0.15］ nmol/mg prot, P <0.05) in the testis tissue. In comparison with the OS model controls, the mice treated with low-, medium- and high-dose EXD exhibited significantly increased epididymal sperm concentration (［8.34 ± 2.59］, ［8.59 ± 1.10］ and ［8.41 ± 1.47］×107/ml) (P <0.01) and motility (［36.04 ± 12.33］%, ［38.87 ± 13.13］% and ［41.90 ± 8.09］%) (P <0.01) and concentrations of SOD (［22.99 ± 1.11］, ［20.82 ± 1.81］ and ［21.33 ± 1.66］ U/mg prot) (P <0.01) and GSH (［104.74 ± 2.47］, ［98.61 ± 12.98］ and ［108.89 ± 5.85］ μmol/L) (P <0.01) but decreased level of MDA (P <0.05).

CONCLUSIONSErxian Decoction can improve cyclophosphamide-induced reduction of sperm concentration and motility, which might be associated with its abilities of resisting oxidation and reducing oxidative stress injury.

Animals ; Cyclophosphamide ; Drugs, Chinese Herbal ; pharmacology ; Epididymis ; Glutathione ; analysis ; Male ; Malondialdehyde ; analysis ; Mice ; Oligospermia ; chemically induced ; drug therapy ; Oxidative Stress ; Random Allocation ; Sperm Count ; Sperm Motility ; drug effects ; physiology ; Spermatozoa ; drug effects ; Superoxide Dismutase ; analysis ; Testis ; anatomy & histology ; chemistry ; drug effects