Prediction of pregnancy by intrauterine insemination using CASA estimates and strict criteria in patients with male factor infertility

The relationship of the male's proctodeal gland size to sperm-egg interaction and the duration of fertility in Japanese quail

In avian species, male fertility significantly impacts reproductive success. This study investigates the relationship between proctodeal gland size in male Japanese quails and sperm function, as well as female fertility duration. Six hundred adult Japanese quails were selected and housed in individual cages. Males (n = 300) were divided into 6 groups (50/group) based on the size of their proctodeal glands. Females (n = 300) were randomly assigned to corresponding groups. After acclimatization, sperm kinematics and the frequency and weight of foam discharge were evaluated. Males were paired with females for 24 h, and eggs were collected for 20 d postcopulation. Eggs were incubated to assess fertility duration. Fresh eggs (n = 20/group/d) were used to assess sperm penetration into the perivitelline membrane on the 2nd, 9th, and 16th d postinsemination. Plasma testosterone levels and the testes' relative weight were determined. The results indicated a significant increase (p < 0.0001) in sperm concentration, total and progressive motility, and nearly all sperm kinematic parameters such as VSL, VCL, VAP, LIN, WOB, and STR values as the size of the proctodeal gland increased. Quails copulated with males having a small and average proctodeal gland area (<400 mm2) laid fertile eggs for a shorter period and had significantly fewer sperm penetration holes than those mated with males having a larger proctodeal gland area (>400 mm2). The proctodeal gland size was positively correlated with testicular weight, plasma testosterone concentrations, and sperm kinetic variables. The results indicate that the size of the proctodeal gland in males can be used to predict sperm function and the duration of fertility in Japanese quail.

The prospect of artificial intelligence to personalize assisted reproductive technology

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

The effect of seminal pathogens on standard semen parameters, sperm kinematics and seminal inflammatory markers

This study evaluated the effects of urogenital pathogens on standard semen parameters, sperm kinematics and host inflammatory response in a cohort of asymptomatic subfertile men. There were six groups based on the results of bacterial culture, including Ureaplasma urealyticum (U. Urealyticum) (n = 27), mixed comprising two or more pathogenic species (n = 28), Gardnerella Vaginalis (G. Vaginalis) (n = 15), gram-positive cocci and bacilli (g+cocci/bacilli) (n = 15), gram-negative bacilli (g-bacilli) (n = 10) and Chlamydia trachomatis (C. trachomatis) (n = 2). One control group (n = 20) and one leukocytospermic group (n = 10) were also included. Sperm quality parameters, seminal leukocytes and interleukin (IL)-6 of all groups, apart from C. trachomatis, were compared to the control group. Standard semen parameters were significantly worse in all groups except for that with g-bacilli. Progressive motility, total motility and normal sperm morphology demonstrated the most significant differences, when U. Urealyticum, leukocytospermia and mixed pathogens were detected in semen. Among sperm kinematics, the concentration of progressive motile sperm cells (CPMS), the percentage of progressive motile sperm cells (PPMS) and straightness (STR) were manifested significant declines in the presence of seminal pathogens. CPMS was affected in all groups except for G. vaginalis. Moreover, the presence of g+cocci/bacilli and g-bacilli were associated with increased seminal IL-6. Seminal leukocytes were elevated significantly only when g-bacilli were cultured in semen. We conclude that seminal pathogens can negatively affect sperm quality. The most negative effect is related to U. Urealyticum. Moreover, g+cocci/bacilli and g-bacilli can initiate an inflammatory response.

New insights from poly-lactic acid and ionomer films coupled with recombinant antibodies for processing sexed-sorting bovine sperm

In this study, the efficacy of ionomers and poly-lactic acid (PLA) as an alternative solid material combined with scFv antibodies specific to bovine Y-sperm (Y-scFv) was studied to create a novel method of sexing technology. The coupling efficiency of Y-scFv to the surface of PLA, Na+ and Zn2+ ionomer film was between 2 and 8 mg/mL. Fourier transform infrared spectra confirm that Y-scFv was bound with a carboxylic acid group in each film. Therefore, Na+, Zn2+ ionomers and PLA films conjugated with 4 and 8 mg/mL Y-scFv showed the highest concentration of Y-sperm in the eluted fraction. Considering that the elute fraction was enriched Y-sperm fraction, it contained 67.70-77.94 % of the Y-sperm ratio related to the produced supernatant fraction, which contained up to 69.31-76.01 % enriched X-sperm. In addition, the sperm quality after the sexing process was analyzed by CASA and imaging flow cytometry, which showed that each polymer did not have a negative effect on sperm motility and acrosome integrity for X-sperm. The capacity of ionomer and PLA combined with Y-scFv are used for bovine sperm sexing.

Effect of sulforaphane on long-term storage of rabbit semen

In this study, it was aimed to determine the effect of sulforaphane (SFN) on rabbit semen cryopreservation. Semen collected from animals was divided into 5 equal volumes as Control, SFN 5 µM, SFN 10 µM, SFN 25 µM and SFN 50 µM groups. Afterwards, semen analyzes were performed. According to our results, there was no statistical difference between the groups at 4°C. However after freezing thawing, the highest total motility, progressive motility and rapid spermatozoa rate was seen in the 10 µM SFN group, while the lowest was observed in the 50 µM SFN group (P<0.05). Static sperm ratio was highest in the 50 µM group, while the lowest was observed in the 10 µM SFN group. When flow cytometry results examined the rate of acrosomal damaged and dead sperm was the lowest in the 10 µM SFN group, a statistical difference was observed between the control group (P<0.05). The highest rate of sperm with high mitochondrial membrane potential was seen in the 5 µM SFN and 10 µM SFN groups. Apoptosis and ROS rates were found to be lower in the experimental groups compared to the control groups (P<0.05). As a result, SFN supplementation at a dose of 10 µM increased the quality of sperm in the freezing and thawing processes of rabbit semen. In conclusion, 10 µM SFN improved the quality of cryopreservation of rabbit semen.

Semen parameters are seriously affected in acephalic spermatozoa syndrome

BACKGROUND

Previous studies have reported that some patients with headless spermatozoa have poor semen quality, but there has been no published systematic analysis of semen quality in patients with different proportions of headless spermatozoa in semen. We aimed to explore the association of acephalic spermatozoa syndrome and semen quality in men with distinct proportions of headless spermatozoa.

MATERIAL AND METHODS

Semen parameter values in patients for whom headless spermatozoa were found in the ejaculates was studied and compared to that of 413 age-matched prenatal examination patients. All semen samples were analyzed following the same methodology in a single laboratory.

RESULTS

All semen parameter values except semen volume were negatively (P < 0.05) correlated with the proportion of headless spermatozoa. The semen samples were divided into four groups on the basis of the proportion of headless spermatozoa (PHS) as follows: 0 < PHS ≤ 5% (n = 172, Group A1); 5 < PHS ≤ 10% (n = 76, Group A2); 10 < PHS ≤ 20% (n = 71, Group B); and PHS > 20% (n = 71, Group C). In Group A1, only one semen parameter value (progressive motility) was lower than those of the control group, but in Group A2, this increased to five (sperm vitality, normal sperm morphology, sperm motility, VCL (curvilinear velocity) and ALH (amplitude of lateral head displacement)). Worse still, all semen parameter values were significantly lower in Group B and Group C than in the control group (P < 0.05).

CONCLUSIONS

Semen samples containing headless spermatozoa tend to have lower quality than samples without headless spermatozoa. Increases in the proportion of headless spermatozoa in semen are associated with decreased semen quality. We suggest that headless spermatozoa should be seriously assessed and accurately counted in semen analysis, especially for ejaculate in which the proportion of headless spermatozoa exceeds 5%.

Effect of Copper Sulphate and Cadmium Chloride on Non-Human Primate Sperm Function In Vitro

In order to address the large percentage of unexplained male infertility in humans, more detailed investigations using sperm functional tests are needed to identify possible causes for compromised fertility. Since many environmental and lifestyle factors might be contributing to infertility, future studies aiming to elucidate the effect of such factors on male fertility will need the use of appropriate research models. The current study aimed to assess the effects of two heavy metals, namely copper sulphate, and cadmium chloride, on non-human primate (NHP) sperm function in order to establish the possibility of using these primate species as models for reproductive studies. Our combined results indicated that the functionality of NHP spermatozoa is inhibited by the two heavy metals investigated. After in vitro exposure, detrimental effects, and significant lowered values (p < 0.05) were obtained for sperm motility, viability and vitality, acrosome intactness, and hyperactivation. These metals, at the tested higher concentrations, therefore, have the ability to impair sperm quality thereby affecting sperm fertilizing capability in both humans and NHPs.

Standard Semen Parameters vs. Sperm Kinematics to Predict Sperm DNA Damage

Purpose

The aims of this study were to associate sperm kinematics and standard semen parameters with sperm DNA damage and to evaluate whether the addition of sperm kinematics improve the multivariable prediction of sperm DNA fragmentation compared to standard semen parameters alone.

Materials and Methods

We evaluated sperm kinematics, standard semen parameters, and DNA fragmentation index (DFI) in 122 men. Univariate and multivariate logistic regression models were fitted to evaluate the association of sperm kinematics and standard semen parameters with pathologically damaged sperm DNA (DFI≥26%), and receiver operating characteristics (ROC) curves were calculated for these models.

Results

On univariate analyses, average velocity, curvilinear velocity, straight-line velocity, straightness (STR), beat-cross frequency (BCF), and the percentage of progressive motile sperm cells (PPMS) were significantly associated with pathologically damaged sperm DNA. Likewise, among standard semen parameters, sperm concentration, progressive motility, normal morphology, and vitality were found to be linked with sperm DNA damage. On the multivariate analysis, vitality was the strongest predictor of pathologically damaged sperm DNA with an area under the ROC curve (AUROC) of 88.3%. Adding STR, BCF, and PPMS to vitality increased the AUROC to the significant extent of 91.5%.

Conclusions

Sperm vitality is the most accurate routine-based laboratory test for the prediction of pathologically damaged sperm DNA, but the addition of sperm kinematics increases its accuracy. Both standard semen parameters and sperm kinematics are complementary in predicting pathologically damaged sperm DNA, and might serve as a new tool to screen for fertile men.

Current perspectives of CASA applications in diverse mammalian spermatozoa

Since the advent of computer-aided sperm analysis (CASA) some four decades ago, advances in computer technology and software algorithms have helped establish it as a research and diagnostic instrument for the analysis of spermatozoa. Despite mammalian spermatozoa being the most diverse cell type known, CASA is a great tool that has the capacity to provide rapid, reliable and objective quantitative assessment of sperm quality. This paper provides contemporary research findings illustrating the scientific and commercial applications of CASA and its ability to evaluate diverse mammalian spermatozoa (human, primates, rodents, domestic mammals, wildlife species) at both structural and functional levels. The potential of CASA to quantitatively measure essential aspects related to sperm subpopulations, hyperactivation, morphology and morphometry is also demonstrated. Furthermore, applications of CASA are provided for improved mammalian sperm quality assessment, evaluation of sperm functionality and the effect of different chemical substances or pathologies on sperm fertilising ability. It is clear that CASA has evolved significantly and is currently superior to many manual techniques in the research and clinical setting.

Impact of age, clinical conditions, and lifestyle on routine semen parameters and sperm kinematics

OBJECTIVE

To assess the impact of aging on routine semen and computer-assisted sperm analysis (CASA) motility parameters according to the current World Health Organization guidelines; and to evaluate the effect of obesity and lifestyle (alcohol consumption, cigarette smoking) in older men's semen.

DESIGN

Blind cross-sectional study.

SETTING

Research laboratory and andrology and reproduction laboratory.

PATIENT(S)

A population of 11,706 men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen analysis: routine (semen volume, sperm concentration and count, motility, vitality, morphology, hypo-osmotic swelling test, round and peroxidase-positive cell concentration) and CASA (straight-line velocity, curvilinear velocity, average path velocity, linearity, straightness, beat cross frequency, wobble, amplitude of lateral head displacement, and mean angular displacement) parameters; and body mass index.

RESULT(S)

A negative correlation was found between age and routine semen parameters: volume, sperm count, motility, vitality, total motile spermatozoa and normal-motile spermatozoa, round cell concentration, and hypo-osmotic swelling test values. Several CASA variables (straight-line velocity, curvilinear velocity, average path velocity, beat cross frequency, amplitude of lateral head displacement, and mean angular displacement) were also negatively affected. Using 40 years as a cut-off value, significant differences in most parameters correlated to age. In a selected subpopulation of men unexposed to known fertility-compromising factors, the same evaluations were performed, finding some parameters still decreased. Although obesity exerted a significant deleterious effect on older patients' semen quality, alcohol consumption and cigarette smoking mildly affected it.

CONCLUSION(S)

Male aging, with the contribution of unhealthy conditions, are paramount effectors of sperm quality deterioration.

Comparison of the characteristics of chinchilla epidydimal semen after collection, storage at 5°C and cryopreservation

The aim of the study was to compare the characteristics of chinchilla epididymal sperm: fresh, stored at liquid state and cryopreserved. Epididymal spermatozoa obtained from 11 males were assessed for subjective motility, concentration, motility parameters measured by CASA, viability, morphology, membrane integrity, acrosome integrity, mitochondrial potential, lipid peroxidation, chromatin structure, apoptotic changes and capacitation. Then half of the spermatozoa were stored at 5°C for 30 hr, and the second half was cryopreserved. After storage and thawing the same parameters as in fresh semen were assessed. Fresh semen showed good quality, with low levels of lipid peroxidation, chromatin fragmentation and capacitation. CASA evaluation showed significantly lower values for MOT, PMOT, RAPID, VCL, VAP and VSL after both storage at liquid state and cryopreservation (p < 0.05). Cold storage did not induce membrane and acrosome damage (p > 0.05), conversely to cryopreservation (p < 0.05). After storage, there was a drop in high mitochondrial potential in live cells (p < 0.05) and an increase in the percentage of non-apoptotic, capacitated cells (p < 0.05). These changes were not seen after cryopreservation (p > 0.05). Lipid peroxidation in live cells and chromatin structure remained unchanged both after storage and cryopreservation (p > 0.05). The study showed that examined methods of semen preservation exerted different patterns of changes in spermatozoa and that sperm quality after both of them allowed for further use of preserved spermatozoa in artificial reproductive techniques.

Metal/metalloid levels in urine and seminal plasma in relation to computer-aided sperm analysis motion parameters

BACKGROUND

Exposure to high levels of metals/metalloids may impair semen quality. Computer-aided sperm analysis (CASA) can be used for kinematic analysis of spermatozoa, which provides additional insights into sperm motion characteristics.

OBJECTIVE

To explore the associations of urinary and seminal plasma metal/metalloid concentrations with CASA motion parameters and assess the degree of correspondence between the two sample types.

METHODS

Eighteen metals/metalloids in seminal plasma and repeated urine samples were determined among 746 men recruited from a reproductive center. We assessed their associations with 6 CASA motion parameters [i.e., straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR) and amplitude head displacement (ALH)] using multivariable linear regression models.

RESULTS

We found significantly inverse dose-dependent relationships between seminal plasma arsenic (As) and VSL, VCL and VAP, between seminal plasma selenium (Se) and VSL and VAP, between seminal plasma zinc (Zn) and STR and LIN, and between seminal plasma manganese (Mn) and LIN in single-metal models [all false discovery rate (FDR) adjusted P for trend < 0.05]. These dose-response relationships remained statistically significant based on multiple-metal models and restricted cubic spline functions. Metal/metalloid concentrations in urine poorly predicted the same-day seminal plasma concentrations [coefficient of determination (R²) < 0.15]. We didn't find any significant associations between urinary metal/metalloid concentrations and the CASA motion parameters.

CONCLUSION

Exposure to high levels of As, Se, Mn and Zn may impair sperm motion capacity. Concentrations of metals/metalloids in spot urine samples cannot accurately predict same-day seminal plasma exposure levels.

Exposure of environmental Bisphenol A in relation to routine sperm parameters and sperm movement characteristics among fertile men

Although several human studies have examined bisphenol A (BPA) exposure in relation to routine sperm parameters, evidence of BPA’s effects on sperm movement characteristics is limited. We examined associations of BPA exposure with sperm parameters including sperm movement characteristics among fertile men. The cross-sectional study was conducted in Sandu County, Guizhou Province, China. Subjects provided semen samples analyzed by computer-aided sperm analysis (CASA) system and urine samples for BPA assay. They were invited to complete an in-person interview with a structured questionnaire to obtain demographics, lifestyle factors, etc. In final analyses, 500 subjects were included. We used multivariate linear regression analyses to estimate associations between BPA and sperm parameters after adjusting for potential confounders. BPA was detected in 73.6% of urine samples, with a geometric mean of 0.44 μg/gCreatinine. Compared with subjects of undetected BPA, subjects with detected BPA had increased Linearity (LIN, β: 2.19, 95% confidence interval (CI): 0.37, 4.0), Straightness (STR, β: 1.47, 95% CI: 0.19, 2.75), Wobble (WOB, β: 1.75, 95% CI: 0.26, 3.25), reduced Amplitude of lateral head displacement (ALH, β: −0.26, 95% CI: −0.5, −0.02) and Mean angular displacement (MAD, β: −2.17, 95% CI: −4.22, −0.11). Subjects in the highest tertile of creatinine-adjusted BPA group had lower sperm concentration than those with undetected BPA. Dose-response relationships of BPA with LIN, WOB, ALH, MAD and sperm concentration were demonstrated by statistically significant trends across tertiles of creatinine-adjusted BPA concentrations. Similar results were obtained using unadjusted BPA concentrations. Exposure to environmental BPA would decrease sperm concentration and sperm swing characteristics (ALH and MAD), and increase sperm velocity ratios (LIN, STR and WOB), which might mediate further effects on impaired male fecundity.

Quantitative assessment of heavy metal effects on sperm function using computer-aided sperm analysis and cytotoxicity assays

One known environmental risk factor impacting on human reproduction is heavy metal pollution. Although some metals (e.g., Cu, Se and Zn) have protective effects on the male reproductive system in low doses, heavy metals can accumulate to toxic levels and result in poor semen quality and decreased sperm function. We investigated the effect of CuSO₄ and CdCl₂ (10, 50, 100 and 250 µg/ml or 500 µg/ml) on human sperm motility and vitality by using computer-aided sperm analysis (CASA) and two cytotoxicity assays (WST-1 and XTT). Several sperm motility parameters were significantly reduced after 5 hr of exposure to the highest concentrations of CuSO₄ (250 µg/ml) and CdCl₂ (500 µg/ml). The WST-1 assay also revealed significantly lower absorbance values for 50, 100 and 250 µg/ml CuSO₄ and for 500 µg/ml CdCl₂ ; however, no significant effect was seen with XTT. The calculated average IC₅₀ value was 50.31±  4.34 µg/ml for CuSO₄ and 392.32  ±76.79 µg/ml for CdCl₂ . The effects of these metals were confirmed with MgCl₂ , a positive control. This study provides threshold concentrations for the harmful effect of CuSO₄ and CdCl₂ on human spermatozoa and recommends the use of WST-1 as vitality assay in future in vitro studies.

Clinical assessment of the male fertility

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed.

CASA in the medical laboratory: CASA in diagnostic andrology and assisted conception

CASA has been used in reproductive medicine and pathology laboratories for over 25 years, yet the ‘fertility industry’ generally remains sceptical and has avoided automation, despite clear weaknesses in manual semen analysis. Early implementers had difficulty in validating CASA-Mot instruments against recommended manual methods (haemocytometer) due to the interference of seminal debris and non-sperm cells, which also affects the accuracy of grading motility. Both the inability to provide accurate sperm counts and a lack of consensus as to the value of sperm kinematic parameters appear to have continued to have a negative effect on CASA-Mot’s reputation. One positive interpretation from earlier work is that at least one or more measures of sperm velocity adds clinical value to the semen analysis, and these are clearly more objective than any manual motility analysis. Moreover, recent CASA-Mot systems offer simple solutions to earlier problems in eliminating artefacts and have been successfully validated for sperm concentration; as a result, they should be viewed with more confidence in relation to motility grading. Sperm morphology and DNA testing both require an evidence-based consensus and a well-validated (reliable, reproducible) assay to be developed before automation of either can be of real clinical benefit.

Intrauterine Insemination: Fundamentals Revisited

Intrauterine insemination (IUI) is an assisted conception technique that involves the deposition of a processed semen sample in the upper uterine cavity, overcoming natural barriers to sperm ascent in the female reproductive tract. It is a cost-effective, noninvasive first-line therapy for selected patients with functionally normal tubes, and infertility due to a cervical factor, anovulation, moderate male factor, unexplained factors, immunological factor, and ejaculatory disorders with clinical pregnancy rates per cycle ranging from 10 to 20%. It, however, has limited use in patients with endometriosis, severe male factor infertility, tubal factor infertility, and advanced maternal age ≥ 35 years. IUI may be performed with or without ovarian stimulation. Controlled ovarian stimulation, particularly with low-dose gonadotropins, with IUI offers significant benefit in terms of pregnancy outcomes compared with natural cycle or timed intercourse, while reducing associated COH complications such as multiple pregnancies and ovarian hyperstimulation syndrome. Important prognostic indicators of success with IUI include age of patient, duration of infertility, stimulation protocol, infertility etiology, number of cycles, timing of insemination, number of preovulatory follicles on the day of hCG, processed total motile sperm > 10 million, and insemination count > 1 × 106 with > 4% normal spermatozoa. Alternative insemination techniques, such as Fallopian tube sperm perfusion, intracervical insemination, and intratubal insemination, provide no additional benefit compared to IUI. A complete couple workup that includes patient history, physical examination, and clinical and laboratory investigations is mandatory to justify the choice in favor of IUI and guide alternative patient management, while individualizing the treatment protocol according to the patient characteristics with a strict cancelation policy to limit multi-follicular development may help optimize IUI pregnancy outcomes.

Evaluation of sperm protamine deficiency and apoptosis in infertile men with idiopathic teratozoospermia

Objective

Sperm morphology plays an important role in infertility, especially in cases of defects in the heads of spermatozoa. Tapered-head or elongated-head spermatozoa are examples of morphological abnormalities. The aim of this study was to compare the semen parameters, levels of protamine deficiency, and frequency of apoptosis between patients with normozoospermia and those with teratozoospermia with tapered-head spermatozoa.

Methods

Fifty-two semen samples (27 patients with tapered-head sperm and 25 fertile men) were collected and semen analysis was performed according to the World Health Organization criteria for each sample. Protamine deficiency and the percentage of apoptotic spermatozoa were evaluated using chromomycin A3 (CMA3) staining and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assays, respectively.

Results

Sperm concentration, motility, and normal morphology in the tapered-head spermatozoa (cases) were significantly lower than in the normozoospermic samples (controls). CMA3-reactive spermatozoa (CMA3+) in the case group were more common than in the controls. Apoptotic spermatozoa (TUNEL-positive) were significantly more common in the cases than in the controls.

Conclusion

This analysis showed that tapered-head spermatozoa contained abnormal chromatin packaging and exhibited a high rate of apoptosis, which can be considered to be an important reason for the impaired fertility potential in teratozoospermic patients with tapered-head spermatozoa.

The significance of clinical practice guidelines on adult varicocele detection and management

Varicoceles are the most common correctable etiology of male factor infertility. However, the detection and management of varicoceles have not been standardized. This has led to decades of debate regarding the effect of varicocele on male infertility and subsequently whether repair leads to an improved fertility status. The current body of evidence investigating the role of varicocele and varicocelectomy is weak and conflicting. The stance taken by the AUA and ASRM suggests that there is insufficient outcomes data to support evidenced-based guidelines, citing evidence used to provide current recommendations are generally of a low quality level. On the other hand, the EAU Guidelines give a level 1a of evidence for management of varicoceles that are clinically palpable, associated with subnormal semen analyses and having otherwise unexplained fertility. Besides aiding with clinical varicocele detection and management, clinical practice opinion statements and guidelines aim to direct and strengthen the infrastructure of future studies. We review the current status of opinion statements and guidelines in varicocele and management detection with focus on their application in practice.

Incidence of Sperm Surface Autoantibodies and Relationship with Routine Semen Parameters and Sperm Kinematics

PROBLEM

Antisperm antibodies (ASA) are associated with male subfertility. However, results on sperm surface autoantibodies are controversial, the relationship between ASA and semen parameters (WHO, 2010) is unknown, and data on ASA and sperm kinematics are scarce.

METHOD OF STUDY

A retrospective study carried out in men undergoing routine semen analysis (WHO 2010), ASA evaluation (direct SpermMAR(™) (IgG) test), and computer-assisted sperm analysis (CASA).

RESULTS

A 2.6% and a 5.9% incidence of ASA-positive cases were found (cut-off 50% and 10%, respectively; n = 7492). ASA-positive samples had lower (P < 0.0001) sperm concentration, count, motility, and hypo-osmotic swelling (HOS) test score. HOS results did not correlate with sperm vitality in normozoospermic samples with high ASA levels. In unselected samples, ASA-positive samples (cut-off 50%) showed decreased sperm kinematics (VSL, VAP, LIN, ALH, STR, BCF, WOB), but in normozoospermic samples, ASA-positive and ASA-negative subgroups had similar CASA results.

CONCLUSIONS

ASA evaluation is highly relevant in full semen assessment.

Isolated abnormal strict morphology is not a contraindication for intrauterine insemination

This study sought to investigate whether isolated abnormal strict morphology (<5% normal forms) and very low strict morphology (0-1% normal forms) affects pregnancy rates in intrauterine insemination (IUI). This was a retrospective study performed at an Academic Medical Center/Reproductive Medicine Center. Four hundred and eight couples were included for 856 IUI cycles. 70 IUI cycles were performed in couples with abnormal strict morphology and otherwise normal semen parameters. Outcomes were measured as clinical pregnancy rate per IUI cycle as documented by fetal heart activity on maternal ultrasound. Clinical pregnancy rate did not significantly differ between the group with abnormal strict morphology [11/70 (15.7%)] and the normal morphology group [39/281 (13.9%)]. Additionally, there was no significant difference between the pregnancy rate in the abnormal morphology group compared to that of our overall institutional IUI pregnancy rate [145/856 (16.9%)]. Furthermore, there was no significant difference between pregnancy rate in the very low morphology group [3/14 (21.4%)] compared to those with normal morphology or the overall IUI pregnancy rate. Patients with isolated abnormal strict morphology have clinical pregnancy rates similar to those with normal morphology for IUI. Even in those with very low normal forms, consideration of IUI for assisted reproduction should not be excluded.

Effects of cholesterol-loaded cyclodextrins on the rate and the quality of motility in frozen and thawed rabbit sperm

The motility of sperm after freezing and thawing is critical for effective cryopreservation. It is known that supplementation with cholesterol-loaded cyclodextrin (CLC) improves cryosurvival of sperm in various animals. To clarify the effects of supplementation with CLC on rabbit sperm motility after freezing and thawing, rabbit sperm motility was analyzed using a computer-assisted sperm analysis system. Sperm motility with CLC supplementation was 29.4 ± 9.6% (mean ± SD), which was significantly higher than that of controls (20.8 ± 7.1%, P<0.05). The curvilinear velocity of sperm with CLC exceeded that of controls, whereas the values for linearity and wobble were significantly lower in sperm with CLC compared with controls. After artificial insemination, 44.3% of recovered ova were fertilized in the CLC-supplemented group, which was higher than the percentage in the control group (36.4%). The results indicate that supplementation with CLC improves the rate and quality of motility in rabbit sperm after freezing and thawing, and would be advantageous for successful cryopreservation.

Semen quality and prediction of IUI success in male subfertility: a systematic review

Many variables may influence success rates after intrauterine insemination (IUI), including sperm quality in the native and washed semen sample. A literature search was performed to investigate the threshold levels of sperm parameters above which IUI pregnancy outcome is significantly improved and/or the cut-off values reaching substantial discriminative performance in an IUI programme. A search of MEDLINE, EMBASE and Cochrane Library revealed a total of 983 papers. Only 55 studies (5.6%) fulfilled the inclusion criteria and these papers were analysed. Sperm parameters most frequently examined were: (i) inseminating motile count after washing: cut-off value between 0.8 and 5 million; (ii) sperm morphology using strict criteria: cut-off value ⩾5% normal morphology; (iii) total motile sperm count in the native sperm sample: cut-off value of 5-10 million; and (iv) total motility in the native sperm sample: threshold value of 30%. The results indicate a lack of prospective studies, a lack of standardization in semen testing methodology and a huge heterogeneity of patient groups and IUI treatment strategies. More prospective cohort trials and prospective randomized trials investigating the predictive value of semen parameters on IUI outcome are urgently needed. It is generally believed that intrauterine insemination (IUI) with homologous semen should be a first-choice treatment to more invasive and expensive techniques of assisted reproduction in cases of cervical, unexplained and moderate male factor subfertility. The rationale for the use of artificial insemination is to increase gamete density at the site of fertilization. Scientific validation of this strategy is difficult because literature is rather confusing and inconclusive. Many variables may influence success rates after IUI treatment procedures. It seems logical that sperm quality has to be one of the main determinants to predict IUI success. Clinical practice would benefit from the establishment of threshold levels for sperm parameters above which IUI pregnancy outcome is significantly improved and below which a successful outcome is unlikely. We performed a literature search to investigate if such threshold levels are known. Most striking were the lack of standardization in semen-testing methodology and the huge heterogeneity of patient groups and IUI treatment strategies. The four sperm parameters most frequently examined were: (i) inseminating motile count after washing: cut-off value between 0.8 and 5 million; (ii) sperm morphology using strict criteria: cut-off value >4% normal morphology; (iii) total motile sperm count in native sperm sample: cut-off value of 5-10 million; and (iv) total motility in native sperm sample: threshold value of 30%. This review identified an urgent need for more and better prospective cohort trials investigating the predictive value of semen parameters on IUI pregnancy rate.

Alkaloids from areca (betel) nuts and their effects on human sperm motility in vitro

An improved high-performance liquid chromatography (HPLC) method was established to rapidly and simultaneously determine 3 main alkaloids (arecoline, arecaidine, and guvacine) in areca (betel) nuts (AN), and 12 AN samples from the main betel palm growing areas on the Chinese Mainland were collected and determined. Semen samples from acceptable volunteers were treated in vitro with different concentrations of the 3 alkaloids to evaluate the effects on sperm motility (SM). Highly motile spermatozoa were selected from the samples and divided into 5 equal fractions. Various concentrations of each alkaloid were added to 4 of the 5 fractions, and 1 fraction was used as a control. All fractions were incubated for 4 h. A computer-aided sperm analysis system was used to measure 5 SM parameters, motility, average path velocity, straight-line velocity, curvilinear velocity, linearity, and amplitude of lateral head displacement. The results showed that the contents of the amount of alkaloids in AN differed markedly in different places in China and were higher in the kernel than in the husk, and higher in dried AN than in fresh AN. Arecoline had the strongest reduction effect on human SM and the effect was strongly dose dependent. Arecaidine had a much weaker reduction effect than arecoline, and guvacine had the least reduction effect. These findings also demonstrate that betel quid could have adverse effects on the gonadal functions of betel quid consumers.

Computer-assisted sperm analysis parameters in young fertile sperm donors and relationship with age

Sperm parameter values have been shown to decline with age, according to conventional sperm analysis. However, the effect of age on sperm kinematic parameters has been rarely studied, especially in young fertile men. Here, we studied Computer-Assisted Sperm Analysis (CASA) parameters in a large cohort of men with proven fertility, in order to determine if there is a decline with age in this young fertile population. This retrospective analysis of CASA parameters was conducted on all donors included in the sperm donor programme in the Assisted Reproductive Techniques (ART) Centre of the University Hospital of Nantes between 2006 and 2009. Sperm concentration, motility, and kinetic parameters were recorded by a HTM-Ceros system and compared in 3 groups of sperm donors according to their age: <35 years, 36-40 years, and 41-44 years. A total of 362 ejaculates from 138 donors were analyzed. Values for ALH, VCL, LIN, and STR significantly decreased with age. Sperm concentration, motile sperm proportion, and other kinetic parameters did not differ significantly among the groups. The use of CASA allowed the identification of ALH, VCL, LIN, and STR age-related decrease in young men with proven fertility.

Predictive value of sperm motility characteristics assessed by computer-assisted sperm analysis in intrauterine insemination with superovulation in couples with unexplained infertility

Objective

To determine whether characteristics of sperm motility obtained by computer-assisted sperm analysis (CASA) could predict pregnancy after intrauterine insemination (IUI) in couples with unexplained infertility.

Methods

Three hundred eighty-three cycles of intrauterine insemination with superovulation were retrospectively analyzed. Semen analysis was performed with CASA before and after swim-up and the parameters were compared between pregnant and non-pregnant women.

Results

The pregnancy rate per cycle was 14.1%. Pregnant and non-pregnant women were comparable in terms of age, infertility duration, the number of dominant follicles. While sperm concentration, motility, and parameters such as average path velocity (VAP) and percentage rapid (RAPID) before semen preparation were significantly different between the pregnancy and non-pregnancy groups, there were no differences in sperm parameters when comparing the two groups after preparation. Using a receiver operating characteristic curve to measure sensitivity and specificity, the optimal threshold value for the predictors of pregnancy was revealed to be a concentration of ≥111×10⁶/mL, a motility of ≥51.4%, and RAPID ≥30.1% before preparation for IUI.

Conclusion

Sperm parameters including concentration, motility, and RAPID before sperm preparation could have predictive value for pregnancy outcome after intrauterine insemination with superovulation in couples with unexplained infertility, and would be helpful when counseling patients before they make the decision to proceed with IVF/ICSI-ET.

Frozen-thawed rhesus sperm retain normal morphology and highly progressive motility but exhibit sharply reduced efficiency in penetrating cervical mucus and hyaluronic acid gel

The preservation of the genetic diversity of captive populations of rhesus monkeys is critical to the future of biomedical research. Cryopreservation of rhesus macaque sperm is relatively simple to perform, yields high post-thaw motility, and theoretically, provides via artificial insemination (AI) a way to easily transfer genetics among colonies of animals. In the interest of optimizing semen cryopreservation methods for use with vaginal AI, we evaluated the ability of frozen-thawed rhesus sperm to penetrate periovulatory cervical mucus (CM). Motile sperm concentration of pre-freeze ("fresh") and post-thawed ("thawed") samples from five different males were normalized for both computer assisted sperm motion analysis and CM penetration experiments. Sperm samples were deposited into slide chambers containing CM or gel composed of hyaluronic acid (HA) as a surrogate for CM and numbers of sperm were recorded as they entered a video field a preset distance from the sperm suspension-CM (or HA) interface. Fresh and thawed sperm were dried on glass slides, "Pap"-stained, and assessed for changes in head dimensions and head and flagellar shape. While retaining better than 80% of fresh sperm progressive motility, thawed sperm from the same ejaculate retained on average only 18.6% of the CM penetration ability. Experiments using HA gel yielded similar results only with reduced experimental error and thus improved detection of treatment differences. Neither the percentage of abnormal forms nor head dimensions differed between fresh and thawed sperm. While findings suggests that sperm-CM interaction is a prominent factor in previous failures of vaginal AI with cryopreserved macaque sperm, neither sperm motility nor morphology appears to account for changes in the ability of cryopreserved sperm to penetrate CM. Our data points to a previously unidentified manifestation of cryodamage which may have implications for assessment of sperm function beyond the cervix and across mammalian species.

Exogenous platelet-activating factor improves the motility of human spermatozoa evaluated with C.A.S.A.: optimal concentration and incubation time

The objective of this study is to determine the optimal conditions for human semen incubation treated with exogenous platelet activating factor (ePAF) for intra-uterine insemination (IUI). This prospective study was carried out on 32 infertile men and each semen sample was processed with the ISolate Sperm Separation Medium, washed with sperm washing medium (SWM) and resuspended either in SWM alone (control samples), or with ePAF 0.1, 0.5, and 1.0 μM. Each concentration was subsequently incubated and evaluated at 5, 15, 30, and 60 min. The motility parameters were evaluated by the computer-aided sperm analysis (C.A.S.A.) system. Curvilinear velocity, straight line velocity, average path velocity, rapid and progressive motility significantly increased compared to control samples at an ePAF concentration of 0.1 μM (with at least 15 min of incubation). The best results were obtained with ePAF concentrations of: 0.1 μM (60 min of incubation) and 0.5 μM (30-60 min of incubation). In conclusion, results are enhanced when ePAF is added to standard semen preparation for IUI. An ePAF concentration of 0.1 μM, with an incubation time of 15 min, can be used for semen samples with normal motility. Whilst, for semen samples with poor motility, the ePAF concentration is best increased to 0.5 μM and/or the incubation time prolonged to 60 min.

Activity of the Na,K-ATPase alpha4 isoform is important for membrane potential, intracellular Ca2+, and pH to maintain motility in rat spermatozoa

While the function of the ubiquitous Na,K-ATPase alpha1 subunit has been well documented, the role of the sperm-specific alpha4 isoform of this ion transporter is less known. We have explored the importance of alpha4 in rat sperm physiology by taking advantage of the high sensitivity of this isoform for the inhibitor ouabain. Using concentrations that selectively block alpha4 activity, we found ouabain to reduce not only sperm total motility, but also multiple parameters of sperm movement, including progressive motility, straight line, curvilinear, and average path velocities, lateral head displacement, beat cross frequency, and linearity. According to a direct role of alpha4 in Na(+) transport, ouabain inhibition of alpha4 increased [Na(+)](i) in the male gametes. In addition, interference of alpha4 activity with ouabain produced cell membrane depolarization, diminished pH, and increased [Ca(2)(+)](i) in spermatozoa. Inhibition of alpha4 was sufficient to cause all these effects and additional blockage of alpha1, the other Na,K-ATPase alpha isoform expressed in sperm, and higher doses of ouabain did not result in further changes in the cell parameters studied. These results show that alpha4 is the Na,K-ATPase isoform primarily involved in controlling the transmembrane Na(+) gradient in sperm, and that alpha4 activity is necessary for maintaining membrane potential, [Ca(2)(+)](i), and [H(+)](i) in the cells. The high dependence of sperm motility on membrane excitability, [Ca(2)(+)](i), and acid-base balance suggests that their regulation is the mechanism by which alpha4 maintains motility of the male gametes.

[Which technique is best for which male infertility?]

To what extent are sperm analyses valid? Does a normality benchmark exist? Analysis of the literature suggests that the normal values for semen parameters defined by the WHO may require reassessment. Other criteria should perhaps be taken into account, such as chromatin or DNA abnormalities. The existing studies are contradictory and the DNA fragmentation rate is not used by the ASRM as a predictor of the pregnancy rate. Several teams have attempted to suggest threshold values for semen parameters, both in cases of intrauterine insemination and ICSI. In the case of IUI, the results are highly variable depending on the study in question. As for ICSI, although there is some consensus of opinion in the data, other findings are controversial or debatable. However, there are few properly conducted randomised prospective studies and very few multivariate analyses.

[Is there an association between sperm normal morphology and their kinetic displacement?]

OBJECTIVE

To evaluate if there exist an association between the % of normal forms and the kinetic characteristics in human spermatozoa

MATERIAL AND METHODS

A retrospective study was performed to analyze semen samples of 203 patients by Computer Assisted Semen Analysis. Sperm morphology was evaluated by the aid of a micrometric objective according to strict criteria. Only the patients presenting >20 x 106 sperm/ml and > 50% of progressive motility were included. Data from 168 patients were divided according to the % of normal forms in three groups a) <4% (n=22), b) between 4-13% (n=89) and c) >14% (n=57). Data collected among groups were compared. In order to select a motile sperm population 35 samples were treated by a discontinuous gradient and the % of normal forms as well as motility parameters evaluated before and after selection.

RESULTS

The kinetic analysis showed that sperm concentration, the % of motile and rapid spermatozoa (>25 microm/s) as well as the average path velocity (VAP) and the lateral head displacement (LHD) were increased in association with the % of normal spermatozoa presenting the lowest values in the group <4% with respect to the > or = 14% group, (p<0.05). Linearity (LIN) remained constant among groups. Kinetic parameters and sperm morphology were significantly increased (p<0.0001) in the selected samples Results showed that the use of gradients even in teratozoospermic samples improves significantly the % of normal forms respect to baseline values (p<0.0002).

CONCLUSIONS

Our results would support the hypothesis that morphologically better spermatozoa would be associated with those with better movement parameters measured in an objective way. In this manner we could suggest that in vivo the best spermatozoa would comprise one "elite" in the journey through the fertilization site.

Predictive value of the hemizona assay for pregnancy outcome in patients undergoing controlled ovarian hyperstimulation with intrauterine insemination

OBJECTIVE

The hemizona assay (HZA) is an established functional test that examines in vitro sperm-zona pellucida binding capacity with high predictive power for fertilization outcome in IVF. The objective of this study was to evaluate the value of the HZA as a predictor of pregnancy in patients undergoing controlled ovarian hyperstimulation (COH) and intrauterine insemination (IUI).

DESIGN

Prospective clinical study.

SETTING

Academic center.

PATIENT(S)

Eighty-two couples with unexplained or male factor infertility that underwent 313 IUI cycles.

INTERVENTION(S)

Basic semen analysis and HZA were performed within three months of starting COH/IUI therapy.

MAIN OUTCOME MEASURE(S)

Hemizona index (HZI) and clinical pregnancy.

RESULT(S)

Overall, patients with an HZI of <30 had a significantly lower pregnancy rate compared to patients with an HZI of > or =30 (11.1% vs. 40.6%, respectively; P<.05; relative risk for failure to conceive: 1.5 (confidence interval 1.2-1.9)). In all patients combined, and in the range of HZI 0-60, the duration of infertility (P=.000) and the HZI (P=.004) were significant determinants of conception (receiver operating characteristics (ROC) analysis). In couples with male infertility, the average path velocity and HZI were significant predictors of conception (P=.001 and P=.005, respectively, ROC analysis). The negative and positive predictive values of the HZA for pregnancy were 93% and 69%, respectively. Logistic regression analysis provided models of HZI (P=.021) and duration of infertility (P=.037) with highest predictability of conception in male factor and unexplained infertility groups, respectively.

CONCLUSION(S)

The HZA predicted pregnancy in the IUI setting with high sensitivity and negative predictive value in couples with male infertility. Results of this sperm function test are useful in counseling couples before allocating them into COH/IUI therapy.

A simple zeta method for sperm selection based on membrane charge

OBJECTIVE

The objectives were: [1] to develop a simple zeta potential method for sperm isolation; and [2] to analyze the sperm maturity, morphology, kinematic, and DNA parameters.

DESIGN

The phenomenon of sticky sperm adhering to slide surfaces was adapted for collecting charged sperm.

SETTING

Clinical and academic research environment.

PATIENT(S)

Discarded colloid-washed sperm from routine laboratory testing (n = 8).

INTERVENTION(S)

Sperm were centrifuged in serum-free medium and collected for analyses.

MAIN OUTCOME MEASURE(S)

Kinematic parameters, DNA integrity, and maturity.

RESULT(S)

The percentages of mature (73.0% +/- 0.5% vs. control 63.5% +/- 0.5% SEM) and DNA intact sperm (85.0% +/- 0.3% vs. 69.5% +/- 0.5%) increased in the male factor subgroup. Strict normal morphology (19.3% +/- 0.1% vs. 10.0% +/- 0.1%), hyperactivation (7.0% +/- 0.1% vs. 3.6% +/- 0.1%), and progressive motility (29.1% +/- 0.1% vs. 19.9% +/- 0.1%) increased by twofold.

CONCLUSION(S)

The zeta method improved sperm parameters associated with increased fertilization and pregnancy after assisted reproduction procedures. Manipulation from the attaching-detaching process stimulated sperm metabolism without causing premature acrosome reactions. Total motility was unchanged suggesting a lack of association between total motility and zeta potential.

Molecular aspects of declining sperm motility in older men

OBJECTIVE

To investigate the molecular mechanism for declining sperm motility in older men.

DESIGN

Retrospective and prospective study.

SETTING

University-based andrology unit.

PATIENT(S)

Semen was collected from 2,111 patients and sperm donors.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Age, sperm concentration, ejaculate volume, sperm motility (including velocity average path, velocity straight line, velocity curvilinear, linearity, and lateral head displacement), normal sperm morphology, percentage of abnormally blue-stained flagella, and total and free T, FSH, and LH concentrations were analyzed. In addition, the zinc concentration in the seminal fluid, flagella, and the whole spermatozoa was measured by means of atomic absorption spectrometry.

RESULT(S)

Patient age correlated negatively with T concentration and sperm motility, including velocity, but positively with the percentage of abnormally stained flagella and the flagellar zinc. Whereas the percentage of abnormally stained flagella correlated negatively with motility and sperm velocity, there was a positive relationship with the flagellar zinc content. Flagellar zinc content was negatively correlated with motility. Testosterone showed a positive relationship with motility and sperm concentration.

CONCLUSION(S)

Because the epididymis is functionally T-dependent, our data suggest that the removal of zinc from the outer dense fibers during epididymal sperm maturation is affected in aging men, which in turn will result in decreased sperm motility.