Semen analysis: looking for an upgrade in class

Sperm acrosin activity may be a useful factor in choosing between ICSI and IVF for infertile male patients

The clinical applications of acrosin activity are limited. We analyzed 61 578 male partners in infertile couples who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya (Changsha, China) between August 2014 and December 2019 to determine the reference ranges and thresholds for acrosin activity in infertile Chinese men; to determine whether correlations exist between acrosin activity and age, sperm concentration, sperm morphology, or sperm motility; and to evaluate whether acrosin activity could serve as an effective prognostic indicator for choosing between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in the clinic. The cut-off value for the normal reference range of acrosin activity for male partners in infertile couples was 24.78 µIU per 10 6 sperm. There was no significant association between acrosin activity and age, sperm concentration, semen volume, total sperm count, progressive motility, or total motile spermatozoa. A weak positive correlation was found between acrosin activity and normal sperm morphology. There was a statistically significant difference in abnormal acrosome morphology between the group with high acrosin activity (>24.78 µIU per 10 6 sperm) and the group with low acrosin activity (<24.78 µIU per 10 6 sperm). The group with a low IVF fertilization rate had a high index of abnormal acrosomal morphology at 21.2%, while the group with a high IVF fertilization rate had a low index of 0.2%. At an acrosin activity of <24.78 µIU per 10 6 sperm, in one cycle of the same patient, the fertilization rate, normal fertilization rate, and good-quality embryo rate for ICSI were significantly higher than those for IVF. Therefore, the most promising application of acrosin activity could be in the selection of ICSI over IVF for infertile male patients with complete fertilization failure or a low fertilization rate.

Utility of evaluating semen samples from adolescents with Klinefelter Syndrome for cryopreservation: A multi-institution evaluation

INTRODUCTION

Klinefelter Syndrome (KS) is the most common genetic condition cause of non-obstructive azoospermia (NOA). KS also often results in decreased testicular growth and testosterone production. Because of this, exogenous testosterone therapy is commonly prescribed for KS patients to treat hypogonadism, but this may have additional impacts to future fertility potential. KS adolescent patients may be asked to provide multiple semen samples to identify potential sperm for early cryopreservation.

OBJECTIVE

To develop a multi-institutional database to evaluate the prevalence of sperm in the ejaculate of adolescent KS patients.

METHODS

A retrospective study was performed of all adolescent KS patients seen at two high-volume tertiary male infertility clinics between 2015 and 2020. Adolescence was defined as individuals aged 12-19 years, as per the World Health Organization. Demographic information data including weight, height, medical comorbidities, and concurrent medications were collected. Serum hormone levels including FSH, LH, and testosterone were collected, as well as any available semen analysis data.

RESULTS

A total of 116 patients were identified and included in the database. A total of 100 (86.2%) had hormone data available and 48 (41.3%) had semen analysis data. Of the 48 patients with semen analyses, only 4 (8.3%) patients had rare sperm in the ejaculate while the remaining had azoospermia (91.7%). None of the specimens were suitable for cryopreservation. The average serum total testosterone level of adolescent KS patients was 181 ± 216 ng/dL. FSH levels were 14.3 ± 18.8 IU/L (normal 0.3-10.0 IU/L) and LH levels were 7.8 ± 12.4 IU/L (normal 1.2-7.8 IU/L). A total of 17 patients repeated a semen analysis, and in no instance did this result in sperm where there was none previously.

CONCLUSION

The findings from a large multicenter retrospective cohort of adolescent KS patients suggest that a single semen analysis is sufficient for attempted cryopreservation purposes, and that multiple semen analyses is not needed.

Evolution of the WHO "Semen" processing manual from the first (1980) to the sixth edition (2021)

As stated clearly in all editions of the WHO Laboratory Manual for the Examination and Processing of Human Semen, the goal of the manual is to meet the growing needs for the standardization of semen analysis procedures. With constant advances in andrology and reproductive medicine and the advent of sophisticated assisted reproductive technologies for the treatment of infertility, the manual has been continuously updated to meet the need for new, evidence-based, validated tests to not only measure semen and sperm variables but also to provide a functional assessment of spermatozoa. The sixth edition of the WHO manual, launched in 2021, can be freely downloaded from the WHO website, with the hope of gaining wide acceptance and utilization as the essential source of the latest, evidence-based information for laboratory procedures required for the assessment of male reproductive function and health.

Semen analysis: a workflow for an appropriate assessment of the male fertility status

Infertility is a worldwide problem that affects 9-15% of couples of reproductive age. In about half of the cases, it recognizes, alone or in combination, a male cause. In addition to a reproductive problem, male infertility can result from a systemic disease. Consequently, semen analysis, a fundamental test in the diagnosis of male infertility, represents a useful indicator not only of a man's reproductive capacity but also of his health and lifestyle. Given the key role of semen analysis, only accredited laboratories should perform it and experienced clinicians should be called into play in its interpretation. In this article, we have extensively examined how the macroscopic and microscopic parameters of semen analysis, alone or associated with each other, allow clinicians to orient towards specific diagnoses that can be confirmed by further ad hoc tests. On this basis, we also proposed a diagnostic flowchart focused on the results of the semen analysis.

Semen quality from patients affected by seminomatous and non-seminomatous testicular tumor

Testicular cancer is considered a rare disease affecting approximately 1% to 2% of the male population. This neoplasm has a cure rate of over 95%; as a result, a major concern is the future of fertility of carriers from this disease. There are several histological subtypes of testicular tumors; however, the Testicular Germ Cell Tumors (TGCTs), comprising both seminoma and non-seminoma tumors, are considered the main subtypes of testicular neoplasms. TGCT are characterized by being a solid tumor that mostly affects young men aged between 15 and 40 years old. While TGCT subtypes may have an invasive potential, seminoma subtype does not affect other cells rather than germ cells, while non-seminomas have more invasive properties and can achieve somatic cells; thus, having a more aggressive nature. This research intends to review the literature regarding information about sperm parameters, correlating the data found in those studies to the subfertility and infertility of patients with TCGTs. Furthermore, it will also correlate the data to the non-seminoma and seminoma histological subtypes from pre- and post-cancer therapy. PubMed databases were used. Searched keywords included: seminoma AND non-seminoma; male infertility; germ cell tumor; chemotherapy AND radiotherapy. Only articles published in English were considered. Current studies demonstrate that both TGCT subtypes promote deleterious effects on semen quality resulting in decreased sperm concentration, declined sperm total motility and an increase in the morphology alterations. However, findings suggest that the non-seminoma subtype effects are more pronounced and deleterious. More studies will be necessary to clarify the behavior of seminoma and non-seminoma tumors implicating the reproductive health of male patients.

Triptonide is a reversible non-hormonal male contraceptive agent in mice and non-human primates

There are no non-hormonal male contraceptives currently on the market despite decades of efforts toward the development of "male pills". Here, we report that triptonide, a natural compound purified from the Chinese herb Tripterygium Wilfordii Hook F displays reversible male contraceptive effects in both mice and monkeys. Single daily oral doses of triptonide induces deformed sperm with minimal or no forward motility (close to 100% penetrance) and consequently male infertility in 3-4 and 5-6 weeks in mice and cynomolgus monkeys, respectively. Male fertility is regained in ~4-6 weeks after cessation of triptonide intake in both species. Either short- or long-term triptonide treatment causes no discernable systematic toxic side effects based on histological examination of vital organs in mice and hematological and serum biochemical analyses in monkeys. Triptonide appears to target junction plakoglobin and disrupts its interactions with SPEM1 during spermiogenesis. Our data further prove that targeting late spermiogenesis represents an effective strategy for developing non-hormonal male contraceptives.

Comparison of two automated sperm analyzers using 2 different detection methods versus manual semen assessment

PURPOSE

The exploration of male infertility is mainly based on semen analysis, but its evaluation might be affected by the operator's competence and subjectivity. This led to the development of automated semen analyzing systems. Despite continuous improvement, the precision and correlation of these automated systems with manual sperm assessment performed strictly according to WHO guidelines remains variable in the literature, and their role in daily practice is debated.

METHODS

In this double blind prospective study, we compared the results provided by 2 automated systems based on different concepts (CASA and electro-optical signal) with manual sperm assessment. Sperm concentration, motility and morphology were performed simultaneously and independently by different operators, blinded to each other.

RESULTS

A total of 102 unselected men attending the andrology department for routine sperm analysis were included in the study. We found no significant difference between each automated method and manual assessment for all sperm parameters, except for sperm morphology assessment where the electro-optical system gave higher results and performed slightly poorer than CASA. Correlation was moderate to high between manual assessment and each automated methods for all sperm parameters, with randomly distributed differences.

CONCLUSIONS

Overall, these results show that both types of automated systems can be implemented in andrology laboratory for routine sperm analysis.

CRIPTO and miR-371a-3p Are Serum Biomarkers of Testicular Germ Cell Tumors and Are Detected in Seminal Plasma from Azoospermic Males

miR-371a-3p is currently the most informative reported biomarker for germ cell tumors (GCTs). Another developmental-related biomarker, CRIPTO, is involved in the regulation of pluripotency and germ cell fate commitment. We aimed to assess the value of CRIPTO as a diagnostic and prognostic biomarker of testicular GCTs (TGCTs) and also to assess its presence in seminal plasma samples, compared with miR-371a-3p. In total, 217 and 94 serum/seminal plasma samples were analyzed. CRIPTO was quantified using ELISA and miR-371a-3p using bead-based isolation followed by RT-qPCR. Methylation profiling (EPIC array) for the CRIPTO promoter region was undertaken in 35 TGCT tissues plus four (T)GCT cell lines. Significantly higher CRIPTO concentration was found in sera of non-seminomas compared to controls (p = 0.0297), and in stage II/III disease compared to stage I (p = 0.0052, p = 0.0097). CRIPTO concentration was significantly positively correlated with miR-371a-3p levels in serum (r = 0.16) and seminal plasma (r = 0.40). CRIPTO/miR-371a-3p levels were significantly higher in seminal plasma controls when compared to serum controls (p = 0.0001, p < 0.0001). CRIPTO/miR-371a-3p were detected both in normospermic and azoospermic males, and levels were higher in TGCTs compared to GCNIS-only. We have provided the largest dataset of evaluation of CRIPTO in serum and seminal plasma of GCTs, showing its potential value as a biomarker of the disease.

Validation of SwimCount™, a Novel Home-Based Device That Detects Progressively Motile Spermatozoa: Correlation with World Health Organization 5th Semen Analysis

Purpose

We evaluated the usefulness of a home-based device (SwimCount™) compared with World Health Organization (WHO) 5th semen analysis in screening for male fertility in Asian men.

Materials and Methods

One hundred Asian men who visited CHA Seoul Station Fertility Center for evaluation of fertility were included. Semen samples were analyzed and compared with the SwimCount™ results. An aliquot of 0.5 mL of the semen sample was added to the SwimCount™ and a WHO 5th semen analysis was performed. Results were categorized as low (<5×10⁶/mL), and normal to high (≥5×10⁶/mL) total progressively motile sperm concentration. Receiver operating characteristic curve analysis was performed to evaluate the accuracy of the SwimCount™.

Results

The mean total progressively motile sperm concentration was 26.7×10⁶/mL. Semen analysis revealed that 28% of the samples were below the threshold count of 5 million/mL total progressively motile sperm concentration. The mean total progressively motile sperm concentration of the light color SwimCount™ result group determined by semen analysis was 7.5×10⁶/mL, and the mean total progressively motile sperm concentration of the moderate to dark color SwimCount™ result group was 34.2×10⁶/mL. An area under the receiver operating characteristic curve of 0.85 (95% confidence interval, 0.77–0.94; p<0.001) was obtained when the SwimCount™ was compared with semen analysis. The sensitivity and specificity were obtained at a cut off value of 5.0×10⁶/mL total progressively motile sperm concentration, giving a sensitivity and specificity of 87.5% and 73.4%.

Conclusions

We confirmed the reliability of the SwimCount™ as a home-based device for male fertility by evaluating the total progressively motile sperm concentration.

Inconsistent Adoption of World Health Organization V (2010) Semen Analysis Reference Ranges in the United States Eight Years After Publication

OBJECTIVE

To determine the percentage of laboratories in the United States that have adopted the World Health Organization 2010 (WHO 5) semen analysis (SA) reference values 6years after their publication.

METHODS

Laboratories were identified via 3 approaches: using the Clinical Laboratory Improvement Amendments (CLIA) website, the CDC's 2015 Assisted Reproductive Technology Fertility Clinical Success Rate Report, and automated web searches. Laboratories were contacted by phone or email to obtain de-identified SA reports and reference ranges.

RESULTS

We contacted 617 laboratories in 46 states, of which 208 (26.7%) laboratories in 45 states were included in our analysis. 132 (63.5%) laboratories used WHO 5 criteria, 57 (27.4%) used WHO 4 criteria, and 19 (9.1%) used other criteria. WHO 5 criteria adoption rates varied by geographic region, ranging from 87.5% (35/40) in the Midwest to 50.0% (33/66) in the West. There was a greater adoption rate of WHO 5 reference values in academic affiliated (23/26, 88.5%) compared to non-academic affiliated laboratories (110/182, 60.4%) (P = .028).

CONCLUSION

While the majority of laboratories have adopted WHO 5 criteria following its release 6years ago, a large percentage (36.5%) use what is now considered outdated criteria. This variability could result in the characterization of a male's semen values as being "within reference range" at one center and "outside of reference range" at another. This inconsistency in classification may result in confusion for the both patient and physician and potentially shift the burden of infertility evaluation and treatment to the female partner.

Home sperm testing device versus laboratory sperm quality analyzer: comparison of motile sperm concentration

OBJECTIVE

To test the ability of the smartphone-based YO Home Sperm Test to accurately and precisely measure motile sperm concentration (MSC) versus the SQA-Vision, an automated laboratory semen analyzer.

DESIGN

MSC compared for the YO device on Galaxy and iPhone smartphones versus the SQA-Vision in a double-blind manner.

SETTING

Academic medical center.

PATIENT(S)

Donor semen samples from 24 men in 144 aliquots.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Accuracy, precision, and agreement assessed between the YO device and the SQA-Vision for MSC results.

RESULT(S)

The YO device demonstrated good correlation and good to moderate agreement with the SQA-Vision for MSC results up to a range of 94 × 10⁶/mL with Pearson and concordance correlation coefficient above 0.92. The YO also showed a very high level of accuracy (97.8%) with positive and negative percent agreement above 94%. The difference in coefficient of variation between the YO and the SQA-Vision was low (between 9.4% and 11.2%) and not statistically significant. The precision among the YO phone devices was lower (16.0%) than the manufacturer's claim of ≤20%.

CONCLUSION(S)

The smartphone-based device has a high level of accuracy and precision when compared with the SQA-Vision. It can detect samples with abnormally "low" MSC (below 6 × 10⁶/mL cutoff), which supports its use as an effective home sperm test for screening "low" and "moderate/normal" MSC cases. In addition, the device effectively identifies varying levels of normal MSC in a precise manner over a wide range of normal MSC. Thus, the YO Score can improve patient satisfaction and empowerment.

Is sperm DNA fragmentation a useful test that identifies a treatable cause of male infertility?

The present-day laboratory methods of sperm analysis are a poor predictor of reproductive outcome, and for many years it has been clear that newer and better tests are required. Although many such tests have been proposed, only those which determine sperm DNA quality are still being considered. Of these, several tests of sperm DNA fragmentation are available, although there is presently no consensus about the most appropriate test, the best test specimen (fresh or washed sperm) or what level of fragmentation is of clinical concern. Moreover, although several strategies have been proposed to reduce DNA fragmentation, there is no universal approach and few randomised trials have tested these in a clinical context. As such, most professional bodies do not presently support the use of sperm DNA fragmentation tests, and it is clear that large randomised trials are still required to further evaluate their clinical effectiveness.

1H Magnetic Resonance Spectroscopy of live human sperm

STUDY QUESTION

Can ¹H Magnetic Resonance Spectroscopy (MRS) be used to obtain information about the molecules and metabolites in live human spermatozoa?

SUMMARY ANSWER

Percoll-based density gradient centrifugation (DGC) followed by a further two washing steps, yielded enough sperm with minimal contamination (<0.01%) from seminal fluid to permit effective MRS which detected significant differences (P < 0.05) in the choline/glycerophosphocholine (GPC), lipid and lactate regions of the ¹H MRS spectrum between sperm in the pellet and those from the 40%/80% interface.

WHAT IS KNOWN ALREADY

Current methods to examine sperm are either limited in their value (e.g. semen analysis) or are destructive (e.g. immunohistochemistry, sperm DNA testing). A few studies have previously used MRS to examine sperm, but these have either looked at seminal plasma from men with different ejaculate qualities or at the molecules present in pooled samples of lyophilized sperm.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Sperm suspended in phosphate buffered saline (PBS) at 37°C were examined by ¹H MRS scanning using a ¹H excitation-sculpting solvent suppression sequence after recovery from fresh ejaculates by one of three different methods: (i) simple centrifugation; (ii) DGC with one wash; or (iii) DGC with two washes. In the case of DGC, sperm were collected both from the pellet (‘80%’ sperm) and the 40/80 interface (‘40%’ sperm). Spectrum processing was carried out using custom Matlab scripts to determine; the degree of seminal plasma/Percoll contamination, the minimum sperm concentration for ¹H MRS detection and differences between the ¹H MRS spectra of ‘40%’ and ‘80%’ sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

DGC with two washes minimized the ¹H MRS peak intensity for both seminal plasma and Percoll/PBS solution contamination while retaining sperm specific peaks. For the MRS scanner used in this study, the minimum sperm concentration required to produce a choline/GPC ¹H MRS peak greater than 3:1 signal to noise ratio (SNR) was estimated at ~3 × 10⁶/ml. The choline/GPC and lactate/lipid regions of the ¹H spectrum were significantly different by two-way ANOVA analysis (P < 0.0001; n = 20). ROC curve analysis of these region showed significant ability to distinguish between the two sperm populations: choline/GPC ROC AUC = 0.65–0.67, lactate/lipid ROC AUC = 0.86–0.87.

LIMITATIONS, REASONS FOR CAUTION

Only 3–4 semen samples were used to assess the efficacy of each sperm washing protocol that were examined. The estimated minimum sperm concentration required for MRS is specific to the hardware used in our study and may be different in other spectrometers. Spectrum binning is a low resolution analysis method that sums MRS peaks within a chemical shift range. This can obscure the identity of which metabolite(s) are responsible for differences between sperm populations. Further work is required to determine the relative contribution of somatic cells to the MRS spectrum from the ‘40%’ and ‘80%’ sperm.

WIDER IMPLICATIONS OF THE FINDINGS

¹H MRS can provide information about the molecules present in live human sperm and may therefore permit the study of the underlying functional biology or metabolomics of live sperm. Given the relatively low concentration of sperm required to obtain a suitable MRS signal (~3 × 10⁶/ml), this could be carried out on sperm from men with oligo-, astheno- or teratozoospermia. This may lead to the development of new diagnostic tests or ultimately novel treatments for male factor infertility.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by the Medical Research Council Grant MR/M010473/1. The authors declare no conflicts of interest.

Nanomechanical sensors for direct and rapid characterization of sperm motility based on nanoscale vibrations

Infertility, whether of male or female origin, is a critical challenge facing the low birth rate and aging population throughout the world, and semen analysis is a cornerstone of the diagnostic evaluation of the male contribution to infertility. This means that tools which can characterize sperm properties in an effective manner are very much needed. The conventional approaches are essentially image-based, which have a limited value for analyzing sperm properties. Here, we show that an assay using nanomechanical sensors can detect sperm motility based on nanomotion. We use microcantilever sensors to directly characterize the mechanical response of the sperm based on the fluctuations of microcantilevers. We applied this methodology to sperms exposed to different chemical or physical agents. Real-time nanomechanical fluctuations showed that living sperms produced smaller fluctuations after treatment with inhibitory chemicals, and larger fluctuations after treatment with stimulatory chemicals. Our preliminary experiments suggest that the frequency of fluctuation is associated with sperm motility. This technique offers a brand-new perspective in the characterization of the sperm. By combining conventional measurements, reproductive medicine doctors and researchers should now be able to achieve unprecedented depth in the sperm properties.

Uncertainty of measurement and clinical value of semen analysis: has standardisation through professional guidelines helped or hindered progress?

This article suggests that diagnostic semen analysis has no more clinical value today than it had 25-30 years ago, and both the confusion surrounding its evidence base (in terms of relationship with conception) and the low level of confidence in the clinical setting is attributable to an associated high level of 'uncertainty'. Consideration of the concept of measurement uncertainty is mandatory for medical laboratories applying for the ISO15189 standard. It is evident that the entire semen analysis process is prone to error every step from specimen collection to the reporting of results and serves to compound uncertainty associated with diagnosis or prognosis. Perceived adherence to published guidelines for the assessment of sperm concentration, motility and morphology does not guarantee a reliable and reproducible test result. Moreover, the high level of uncertainty associated with manual sperm motility and morphology can be attributed to subjectivity and lack a traceable standard. This article describes where and why uncertainty exists and suggests that semen analysis will continue to be of limited value until it is more adequately considered and addressed. Although professional guidelines for good practice have provided the foundations for testing procedures for many years, the risk in following rather prescriptive guidance to the letter is that unless they are based on an overwhelmingly firm evidence base, the quality of semen analysis will remain poor and the progress towards the development of more innovative methods for investigating male infertility will be slow.

On the Origins of the Semen Analysis: A Close Relationship with the History of the Reproductive Medicine

The spermatozoa were first seen in ejaculates in the 17^th century. However, the basic mechanisms of human fertilization have been only fully understood after the discovery of ovum in 1827. As a result, the interest in developing technologies for semen analysis arose from the early 1900s. Indeed, standard methodologies for semen analysis were designed mostly along the first half of the 20^th century. Before the 1930s, semen analysis was nearly unavailable clinically, since there were still no robust methodologies for assessing sperm characteristics, as well as to set up standard references that could be able to assess the reproductive capacity of men. However, joining some methodologies reported from 1910 up to 1930, standardization was attained and thereby semen analysis increasingly assumed its role in laboratory practice for investigating men in barren marriage. This article aims in reviewing historical backgrounds on the semen analysis, up to its insertion in laboratory practice. Emphasis is given to the major studies that contributed either directly or indirectly in developing the earliest routine for the semen analysis.

Paper-Based Quantification of Male Fertility Potential

BACKGROUND

More than 70 million couples worldwide are affected by infertility, with male-factor infertility accounting for about half of the cases. Semen analysis is critical for determining male fertility potential, but conventional testing is costly and complex. Here, we demonstrate a paper-based microfluidic approach to quantify male fertility potential, simultaneously measuring 3 critical semen parameters in 10 min: live and motile sperm concentrations and sperm motility.

METHODS

The device measures the colorimetric change of yellow tetrazolium dye to purple formazan by the diaphorase flavoprotein enzyme present in metabolically active human sperm to quantify live and motile sperm concentration. Sperm motility was determined as the ratio of motile to live sperm. We assessed the performance of the device by use of clinical semen samples, in parallel with standard clinical approaches.

RESULTS

Detection limits of 8.46 and 15.18 million/mL were achieved for live and motile sperm concentrations, respectively. The live and motile sperm concentrations and motility values from our device correlated with those of the standard clinical approaches (R2 ≥ 0.84). In all cases, our device provided 100% agreement in terms of clinical outcome. The device was also robust and could tolerate conditions of high absolute humidity (22.8 g/m3) up to 16 weeks when packaged with desiccant.

CONCLUSIONS

Our device outperforms existing commercial paper-based assays by quantitatively measuring live and motile sperm concentrations and motility, in only 10 min. This approach is applicable to current clinical practices as well as self-diagnostic applications.

Sperm selection in natural conception: what can we learn from Mother Nature to improve assisted reproduction outcomes?

BACKGROUND

In natural conception only a few sperm cells reach the ampulla or the site of fertilization. This population is a selected group of cells since only motile cells can pass through cervical mucus and gain initial entry into the female reproductive tract. In animals, some studies indicate that the sperm selected by the reproductive tract and recovered from the uterus and the oviducts have higher fertilization rates but this is not a universal finding. Some species show less discrimination in sperm selection and abnormal sperm do arrive at the oviduct. In contrast, assisted reproductive technologies (ART) utilize a more random sperm population. In this review we contrast the journey of the spermatozoon in vivo and in vitro and discuss this in the context of developing new sperm preparation and selection techniques for ART.

METHODS

A review of the literature examining characteristics of the spermatozoa selected in vivo is compared with recent developments in in vitro selection and preparation methods. Contrasts and similarities are presented.

RESULTS AND CONCLUSIONS

New technologies are being developed to aid in the diagnosis, preparation and selection of spermatozoa in ART. To date progress has been frustrating and these methods have provided variable benefits in improving outcomes after ART. It is more likely that examining the mechanisms enforced by nature will provide valuable information in regard to sperm selection and preparation techniques in vitro. Identifying the properties of those spermatozoa which do reach the oviduct will also be important for the development of more effective tests of semen quality. In this review we examine the value of sperm selection to see how much guidance for ART can be gleaned from the natural selection processes in vivo.

Intracytoplasmic sperm injection (ICSI) in extreme cases of male infertility

INTRODUCTION

Severely compromised spermatogenesis typical of men with virtual azoospermia or non-obstructive azoospermia requires an extreme search for spermatozoa. Our goal was to evaluate the usefulness of a meticulous search carried out in ejaculated or surgically retrieved specimens in achieving pre- and post-implantation embryo development.

PATIENTS AND METHODS

In a retrospective cohort study carried out in an academic institution, intracytoplasmic sperm injection (ICSI) outcomes were reviewed as a function of length of microscopic sperm search in ejaculated and surgically retrieved specimens. Couples whose male partner presented with either virtual or non-obstructive azoospermia were treated by ICSI and categorized according to the time spent in identifying and retrieving enough spermatozoa to inject all the oocyte cohort. Semen parameter, fertilization, pregnancies, deliveries, and child welfare in relation to increasing search time were analyzed and compared.

RESULT(S)

The maternal and paternal ages were comparable in both ejaculated and testicular sperm extraction (TESE) groups along with the oocytes retrieved. The fertilization rates for both ejaculated and TESE progressively decreased with increasing time (P<0.0001). Clinical pregnancies in the ejaculated cohort remained satifactory. In the TESE cohort, there was a decrease in pregnancy rate with increasing time, from 44% to 23%. In a limited number of cases, offspring health was evaluated in both semen sources and appeared reassuring.

CONCLUSION(S)

An extensive and at time exhaustive sperm quest yields kinetically and morphologically impaired spermatozoa without apparent impact on embryo developmental competence. Retrieval of spermatozoa from the seminiferous tubules provided more consistent fertilization and pregnancy outcomes than those retrieved from the ejaculate. A trend indicated that pregnancy rate decreased as search time increased in the TESE group. The utilization of the scarce and unselected spermatozoa did not obviously impair embryo development or cause post-implantation errors.

Development of a simplified method of human semen storage for the testing of sperm DNA fragmentation using the Halosperm G2 test kit

OBJECTIVE

To develop a simple, convenient, and stable storage method for semen before DNA fragmentation testing.

DESIGN

Experimental cross-sectional study.

SETTING

Fertility clinic.

PATIENT(S)

164 male partners of infertile couples.

INTERVENTION(S)

Comparison of sperm DNA fragmentation levels (DFLs) using fresh, snap-frozen and air-dried semen, with air-dried samples stored at different temperatures and time periods to assess DNA stability.

MAIN OUTCOME MEASURE(S)

DFL determined by Halosperm G2 kit.

RESULT(S)

Results are expressed as mean ± standard error of the mean. The DFLs from fresh and air-dried semen gave comparable results (1.08% ± 0.65%), and from snap-frozen and fresh samples a statistically significant difference (5.5% ± 1.09%). Air-dried semen stored at room temperature for 7 days had a statistically significantly higher DFL compared with semen stored overnight (46.29% ± 9.12%). Samples stored at 4°C for 7 days or 1 day showed no statistically significant difference (0.83% ± 0.82%). DFLs from samples stored for either 1 or 30 days at 4°C showed a statistically significant difference (19.59% ± 5.72%); those stored at -22°C showed no statistically significant difference (0.68% ± 0.53%).

CONCLUSION(S)

Air-drying semen is a simple and stable storage method for up to 1 month at -22°C before DNA fragmentation testing.

Assessing the reproductive health of men with occupational exposures

The earliest report linking environmental (occupational) exposure to adverse human male reproductive effects dates back to1775 when an English physician, Percival Pott, reported a high incidence of scrotal cancer in chimney sweeps. This observation led to safety regulations in the form of bathing requirements for these workers. The fact that male-mediated reproductive harm in humans may be a result of toxicant exposures did not become firmly established until relatively recently, when Lancranjan studied lead-exposed workers in Romania in 1975, and later in 1977, when Whorton examined the effects of dibromochloropropane (DBCP) on male workers in California. Since these discoveries, several additional human reproductive toxicants have been identified through the convergence of laboratory and observational findings. Many research gaps remain, as the pool of potential human exposures with undetermined effects on male reproduction is vast. This review provides an overview of methods used to study the effects of exposures on male reproduction and their reproductive health, with a primary emphasis on the implementation and interpretation of human studies. Emphasis will be on occupational exposures, although much of the information is also useful in assessing environmental studies, occupational exposures are usually much higher and better defined.

Effect of luteal phase support after ovulation induction and intrauterine insemination

OBJECTIVE

This study aimed to evaluate the effect of luteal phase support on clinical pregnancy and live birth rates after ovulation induction and intrauterine insemination (IUI).

METHODS

579 cycles from 2010 to 2013 were retrospectively evaluated. Ovarian stimulation was performed with gonadotropins, and rHCG was used for ovulation triggering. All patients received IUI. 451 cycles were supported by receiving vaginal micronized progesterone capsules (142 cycles) or vaginal progesterone gel (309 cycles) whereas 128 cycles were not supported.

RESULTS

Clinical pregnancy (20.6 versus 9.4%; p = 0.004) and live birth rates (14 versus 7%; p = 0.036) were higher for supported group than for unsupported group. Progesterone gel and micronized progesterone subgroups achieved similar clinical pregnancy and live birth rates (21.4 versus 19%, p = 0.567 and 14.2 versus 13.4%, p = 0.807; respectively).

CONCLUSIONS

Luteal phase support improved the success of IUI cycles affecting both clinical pregnancy and live birth rates when gonadotropins were used for ovulation induction. The use of vaginal progesterone gel or micronized progesterone significantly improves clinical pregnancy rates. The live birth rates were higher in the progesterone gel group, but were similar in the micronized progesterone group compared to the unsupported group.

Epigenetic regulation of the RHOX homeobox gene cluster and its association with human male infertility

The X-linked RHOX cluster encodes a set of homeobox genes that are selectively expressed in the reproductive tract. Members of the RHOX cluster regulate target genes important for spermatogenesis promote male fertility in mice. Studies show that demethylating agents strongly upregulate the expression of mouse Rhox genes, suggesting that they are regulated by DNA methylation. However, whether this extends to human RHOX genes, whether DNA methylation directly regulates RHOX gene transcription and how this relates to human male infertility are unknown. To address these issues, we first defined the promoter regions of human RHOX genes and performed gain- and loss-of-function experiments to determine whether human RHOX gene transcription is regulated by DNA methylation. Our results indicated that DNA methylation is necessary and sufficient to silence human RHOX gene expression. To determine whether RHOX cluster methylation associates with male infertility, we evaluated the methylation status of RHOX genes in sperm from a large cohort of infertility patients. Linear regression analysis revealed a strong association between RHOX gene cluster hypermethylation and three independent types of semen abnormalities. Hypermethylation was restricted specifically to the RHOX cluster; we did not observe it in genes immediately adjacent to it on the X chromosome. Our results strongly suggest that human RHOX homeobox genes are under an epigenetic control mechanism that is aberrantly regulated in infertility patients. We propose that hypermethylation of the RHOX gene cluster serves as a marker for idiopathic infertility and that it is a candidate to exert a causal role in male infertility.

Double-blind prospective study comparing two automated sperm analyzers versus manual semen assessment

PURPOSE

Despite controversy regarding its clinical value, male fertility investigation mainly relies on semen analysis. Even though reference guidelines are available, manual sperm analysis still suffers from analytical variability, thus questioning the interest of automated sperm analysis systems. The aim of this study is to compared automated computerized semen analysis systems (SQA-V GOLD and CASA CEROS) to the conventional manual method in terms of accuracy and precision.

METHODS

We included 250 men in this double-blind prospective study. The SQA-V GOLD (Medical Electronic Systems) and CEROS, CASA system (Hamilton Thorne) were compared to the standard manual assessment based on the WHO 5th Edition. The main outcome measures were sperm concentration, total sperm number, total motility, progressive motility, non-progressive motility, morphology, motile sperm concentration (MSC) and progressively motile sperm concentration (PMSC) with the three methods.

RESULTS

Statistical analysis of the test results from the automated systems and the manual method demonstrated no significant differences for most of the semen parameters. The Spearman coefficients of rank correlation (rho) for CASA and the SQA-V GOLD automated systems vs. the manual method were: Sperm concentration (0.95 and 0.95), total sperm number (0.95 and 0.95), MSC (0.94 and 0.96) and PMSC (0.94 and 0.93) correspondingly. Concerning sperm morphology, both automated systems demonstrated high specificity (Sp) and negative predictive values (NPV), despite significantly different medians (CASA: 83.7 % for Sp and 95.2 % for NPV, SQA-V: 97.9 % for Sp and 92.5 %). The highest precision (lowest 95 % confidence interval for duplicate tests) for all semen variables was found in the SQA-V GOLD.

CONCLUSIONS

The advantages of using automated semen analysers are: Standardization, speed (lower turnaround time), precision, reduced potential for human error, automated data recording and less need for highly skilled professionals to run the systems. The disadvantages of using automated systems are: notably the problem with testing some atypical samples and the inability to perform an assessment of morphology abnormalities. Based on the results of this study, the SQA-V Gold demonstrated better agreement vs. the manual method. In conclusion, automated semen analyzers can be used for routine semen analysis providing rapid clinically acceptable results with higher precision, and positively impacting laboratory standardization.

Semen assessment

Semen analysis initiates the evaluation of the male partner of an infertile couple, and is generally the first test ordered when a couple presents with concerns of infertility. This article outlines the steps involved in the initial evaluation of the man's fertility potential, the interpretation of the results, and the prognostic value of these results. A look into the future of this long-standing test concludes with some interesting concepts for male infertility evaluation.

Direct Characterization of Motion-Dependent Parameters of Sperm in a Microfluidic Device: Proof of Principle

BACKGROUND

Semen analysis is essential for evaluating male infertility. Besides sperm concentration, other properties, such as motility and morphology, are critical indicators in assessing sperm quality. Nevertheless, rapid and complete assessment of these measures still presents considerable difficulty and involves a range of complex issues. Here we present a microfluidic device capable of quantifying a range of properties of human sperm via the resistive pulse technique (RPT).

METHODS

An aperture, designed as a long channel, was used to allow the quantification of various properties as sperm swam through.

RESULTS

The time trace of the voltage drop across the aperture during sperm passage contained a wealth of information: the sperm volume was presented by the amplitude of the induced pulse, the swim velocity was evaluated via the duration, and the beat frequency was calculated from the voltage undulation superposed on the pulse signal. The RPT measurement of swim velocity and beat frequency showed a correlation with the same observation in a microscope (R2 = 0.94 and 0.70, respectively).

CONCLUSIONS

The proposed proof of principle enables substantial quantification of the motion-dependent properties of sperm. Because this approach requires only a current/voltage source and data analysis, it is economically advantageous compared with optical methods for characterizing sperm motion. Furthermore, this approach may be used to characterize sperm morphology.