Clinical tests of sperm fertilizing ability

Study on sperm motility and velocity parameters of freshly collected mithun semen through computer-assisted sperm analyser (CASA)

The objective of this study was to evaluate the quality of mithun semen by computer assisted sperm analysis (CASA). Ejaculates (50) were analysed by CASA. Semen motility was evaluated for kinetics parameters. The percentage of total motile and progressive motile spermatozoa were determined. Several velocities parameters were also determined viz., average path velocity (VAP, μm/s), track speed (VCL,μm/s), progressive velocity (VSL, μm/s), lateral amplitude (ALH), beat frequency (BCF, Hz), straightness (%), elongation (%), linearity (%), and area (μm sq). The result revealed a strong positive correlation between various CASA parameters (PMOTVAP, PMOT- VSL, VAP-VSL, VAP-ALH, VSL-ALH, STR-LIN).The present study confirmed the usefulness of CASA for a quick and objective analysis of sperm concentration, motility and other velocity parameters.

Pig Spermatozoa Defect in Acrosome Formation Caused Poor Motion Parameters and Fertilization Failure through Artificial Insemination and In vitro Fertilization

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry.

Computer-Assisted Sperm Analysis of Freezable and Nonfreezable Mithun (Bos frontalis) Semen

The present study was undertaken to assess the motility and velocity parameters of sperm of freezable and nonfreezable ejaculates by computer-assisted sperm analyser (CASA) such as Hamilton-Thorne Semen Analyser IVOS 11 in mithun semen. Fifty ejaculates (twenty-five ejaculates each for freezable and nonfreezable semen ejaculates) were collected from ten matured mithun bulls. CASA parameters, motility parameters such as forward progressive motility (FPM) (%), nonprogressive motility (NPM) (%), total motility (TM) (%), and static sperms (SM) (%); velocity parameters such as curvilinear velocity (VCL) (μm/sec), straight line velocity (VSL) (μm/sec), average path velocity (VAP) (μm/sec), linearity (LIN) (%), straightness (STR) (%), wobble (WOB) (%), amplitude of lateral head displacement (ALH) (μm), and beat/cross-frequency (BCF) (Hz) were measured by CASA analyser. The result revealed that these parameters varied significantly (P<0.05) between the freezable and nonfreezable ejaculates and freezable ejaculates have significantly (P<0.05) higher value than nonfreezable ejaculates. It was concluded that most of the CASA parameters were significantly lower in nonfreezable ejaculates than in freezable ejaculates in mithun and confirmed that the CASA was effective for a quick and objective analysis of motility and velocity parameters in mithun semen.

Revised guidelines for human embryology and andrology laboratories

These guidelines provide clinicians with specific guidance on laboratory procedures to ensure that their programs' practice reflects current recommendations.

Relationships among frozen-thawed sperm characteristics assessed via the routine semen analysis, sperm functional tests and fertility of bulls in an artificial insemination program

Frozen semen specimens from 22 Holstein bulls representing a wide range of field fertility levels or nonreturn rates (NRR) were used in this study. Semen specimens were thawed at 37 degrees C for a minimum of 30 sec, followed by assessment via a routine semen analysis (RSA) and other sperm functional tests. The RSA was performed by assessing sperm count, motility and morphological characteristics. Other sperm functional tests were performed by assessing the acrosomal membrane integrity, sperm penetration into the cervical mucus and the sperm membrane functional integrity. Following assessment of sperm characteristics, the fertility data of the various bulls were compared to the RSA and the functional tests results. Bulls of high and low fertility were similar in terms of sperm count and progressive motility (P > 0.05). Other characteristics measured by the RSA and functional tests were significantly higher in high fertility bulls (P < 0.05). Correlation coefficients among the various sperm characteristics and fertility of bulls were highly significant (P < 0.01). The highest correlation coefficients between sperm characteristics and fertility were obtained for motility (r = 0.53; P < 0.01), normal morphology (r = 0.59; P < 0.01) and swollen spermatozoa (r = 0.57; P < 0.01). Analysis of specific sperm swelling patterns showed that those patterns considered to reflect maximal sperm swelling were indicative of high fertility.

Male idiopathic oligoasthenoteratozoospermia

Idiopathic oligoasthenoteratozoospermia (iOAT) affects approximately 30% of all infertile men. This mini-review discussed recent data in this field. Age, non-inflammatory functional alterations in post-testicular organs, infective agents (Chlamydia trachomatis, herpes virus and adeno-associated viruses), alterations in gamete genome, mitochondrial alterations, environmental pollutants and "subtle" hormonal alterations are all considered possible causes of iOAT. Increase of reactive oxygen species in tubules and in seminal plasma and of apoptosis are reputed to affect sperm concentration, motility and morphology. iOAT is commonly diagnosed by exclusion, nevertheless spectral traces of the main testicular artery may be used as a diagnostic tool for iOAT. The following can be considered therapies for iOAT: 1) tamoxifen citrate (20 mg/d) + testosterone undecanoate (120 mg/d) (pregnancy rate per couple/month [prcm]: 3.8%); 2) folic acid (66 mg/d) + zinc sulfate (5 mg/d); 3) L-carnitine (2 g/d) alone or in combination with acetyl-L-carnitine (1 g/d) (prcm: 2.3%); and 4) both carnitines = one 30 mg cinnoxicam suppository every 4 days (prcm: 8.5%). Alpha-blocking drugs improved sperm concentration but not morphology, motility or pregnancy rate. Tranilast (300 mg/d) increased sperm parameters and pregnancy rates in an initial uncontrolled study. Its efficacy on sperm concentration (but not on sperm motility, morphology or prcm) was confirmed in subsequent published reports. The efficacy of tamoxifen + testosterone undecanoate, tamoxifen alone, and recombinant follicle-stimulating hormone is still a matter for discussion.

Progesterone Receptor as an Indicator of Sperm Function

Expression of progesterone receptor (PR) localization on spermatozoa was determined in men with normal and abnormal spermiograms. Studies were also carried out to evaluate the potential of PR as a marker of sperm function. Progesterone receptor expression on spermatozoa from men with normozoospermia (n = 8), oligozoospermia (n = 7), asthenozoospermia (n = 8), oligoasthenozoospermia (n = 7), and teratozoospermia (n = 11) was analyzed using an immunocytochemical method with monoclonal antibodies against PR, and flow cytometry using a cell-impermeable fluorescein-tagged progesterone coupled to BSA complex (P-FITC-BSA). Both methods revealed significantly fewer (P < 0.05) PR-positive spermatozoa in men with oligozoospermia, asthenozoospermia, oligoasthenozoospermia, and teratozoospermia compared with men with normozoospermia, thereby suggesting that down-regulation of PR expression in spermatozoa may be one of the causes of male infertility. Spermatozoa from men with normozoospermia (n = 12), oligozoospermia (n = 12), asthenozoospermia (n = 12), oligoasthenozoospermia (n = 9), and teratozoospermia (n = 10) were exposed to low osmotic conditions in the hypoosmotic swelling (HOS) test and then analyzed for PR expression using P-FITC-BSA complex. A significantly higher percentage (P < 0.05) of spermatozoa with physiologically active plasma membrane (HOS+) lacked PR expression (HOS+PR-) in all categories of men with infertility, thereby suggesting that compared to the HOS test, PR expression is a better indicator of sperm function. Furthermore, PR expression in spermatozoa showed a strong (P < 0.05) positive correlation with their ability to undergo an in vitro acrosome reaction. This was observed in all study groups (i.e., normozoospermia, r = 0.8545; oligozoospermia, r = 0.8711; asthenozoospermia, r = 0.7645; oligoasthenozoospermia, r = 0.9003; and teratozoospermia, r = 0.8676). This suggests a potential role for PR in the events leading to the acrosome reaction in sperm.

Some semen abnormalities may cause infertility by impairing implantation rather than fertilization

The hypo-osmotic swelling (HOS) test measures the functional integrity of the sperm membrane. Although, the sperm membrane is essential for the fertilization of oocytes, several clinical studies suggest that abnormally low HOS test scores do not predict poor or failed fertilization in human in-vitro fertilization trials. However, in-vivo and in-vitro studies clearly demonstrate that a low HOS score is associated with poor pregnancy rates suggesting this sperm defect causes implantation problems rather than fertilization problems. The problem of implantation could be caused by the supernumerary sperm attached to the zona pellucida. Supporting evidence for this theory was demonstrated by finding high pregnancy and implantation rates despite low HOS scores following intracytoplasmic sperm injection which avoids the presence of supernumerary sperm on the zona pellucida. These data thus support theories that some sperm abnormalities may reduce fertility potential by causing implantation disorders rather than problems with fertilization.

Semen analysis at the turn of the century: an evaluation of potential uses of new sperm function assays

Semen analysis is a critical assay in the evaluation of infertility and may yield critical information regarding the etiology and prognosis of many types of reduced male fertility. However, basic semen analysis does not directly measure sperm fertilizing capacity, or many of the biochemical events both prior to and subsequent to fertilization. In the last two decades numerous assays of sperm function have been developed. These assays can be classified as: 1) Assays of general biochemistry and ultrastructure, 2) Assays of zona binding and oocyte penetration, and 3) Assays of postpenetration events. Sperm function assays not only allow an accurate diagnosis of many infertilities not diagnosed by the semen analysis, but can also lead to improved treatment modalities. In this review, basic semen analysis and many sperm function assays are briefly reviewed. Novel uses of sperm function are demonstrated in brief case studies.

Effects of various concentrations of native seminal plasma in cryoprotectant on viability of human sperm

To investigate the effect of native seminal plasma on the recovery of frozen human sperm, various concentrations of seminal plasma (0, 25, 50, 75, and 100%) were used in cryoprotectant for freezing sperm, and the viabilities of frozen-thawed sperm were compared. The post-thaw sperm motility of 50 or 75% seminal plasma in the fertile group was significantly higher than that of 0, 25, or 100%. The post-thaw motility of 75% donor seminal plasma in the patient group was higher than that of other concentrations. It was suggested that a certain concentration of native seminal plasma in cryoprotectant would be helpful to the viability of human sperm cryopreservation.

Mechanism of action of NIM-76: a novel vaginal contraceptive from neem oil

The present study was undertaken to elucidate the mechanism of spermicidal action of NIM-76, a fraction isolated from neem oil. The spermicidal activity of NIM-76 was confirmed using a fluorescent staining technique. NIM-76 was found to affect the motility of the sperm in a dose-dependent manner. Supplementation of pentoxifylline, which is known to enhance the motility of the sperm, could not prevent the spermicidal action of NIM-76. There was a gradual leakage of cytosolic LDH from the sperm in the presence of NIM-76. Electron microscopic studies revealed the formation of pores and vesicles over the sperm head, indicating the damage to the cell membrane. Membrane fluidization studies did not reveal any significant change in the fluidity of sperm cell membrane structure.

Penetration capacity of spermatozoa from patients with oligoasthenoteratozoospermia into bovine cervical mucus before and after therapy with kallikrein

Due to the high degree of subjectivity involved in quantifying sperm motility by light microscopy, it appeared of interest to compare the results obtained with a bovine mucus penetration test (Penetrak) to those of routine laboratory measurement before and after therapy with kallikrein (600 U/day). The study included 45 patients with oligoasthenoteratozoospermia (OAT syndrome) in the absence of genitourinary pathology or abnormal serum hormone levels. Infertile partnership has lasted for a mean of 3.2 years. Analysis of spermiograms and the penetration test were performed before and after 3 months of treatment. Neither of these techniques revealed significant alteration after treatment, nor was there a demonstrable success during the observation period in terms of pregnancy. Judging from these results, (1) kallikrein has no effect in patients with OAT syndrome and (2) the penetration test provides no additional information on the biological quality of ejaculate.

The hypoosmotic swelling test: Its employment as an assay to evaluate the functional integrity of the frozen-thawed bovine sperm membrane

The objective of this study was to determine the effectiveness of the hypoosmotic swelling (HOS) test together with the supravital test as a means of evaluating the functional integrity of frozen-thawed bovine sperm membrane. A solution consisting of equal parts of fructose and sodium citrate was prepared and the osmolality varied from 50 to 300 mOsm/L. From these various solutions under study, the 100 mOsm/L solution resulted in a maximal number of clearly identifiable swollen spermatozoa. The results from the supravital test indicated that the HOS solution preserved the integrity and prevented excessive lysis of the sperm membrane during the assay. A good correlation was found between the percentage of motile spermatozoa and spermatozoa that reacted to the HOS test (r = 0.73) and between the percentage of sperm with intact membranes and HOS reactive sperm (r = 0.81). Spermatozoa showing swelling of the entire tail region accounted for more than 60% of the total swelling for the HOS solution at 100 mOsm/L. The results obtained in this study indicate that frozen-thawed bovine spermatozoa did react to the HOS test. This technique could prove useful in studies involving the function of the sperm membrane and could possibly predict the sperm's ability to fertilize.

Risk factors for antisperm antibodies in infertile men

PROBLEM

The prevalence of anti-sperm antibodies (ASAs) in the general population is 0 to 2%; the prevalence in infertile men is much higher at 7 to 26%. However, the role of ASAs in male infertility remains controversial to date. Although several risk factors for ASA development have been defined (such as testicular torsion, varicocele, cryptorchidism, vasectomy, and genital tract infection), there are no specific indications for ASA testing.

METHOD

In order to examine if a single parameter exists identifying patients with elevated ASA titers, serum ASA testing was performed with an enzyme-linked immunosorbent assay (ELISA) in 226 consecutive male patients. The new assay, synchron ELISA (Synelisa) used in our study represents a new type of ELISA without fixation of the sperm surface antigens by formaldehyde or glutaraldehyde. Therefore, the quantitative assay is highly sensitive and reproducible since the structure of sperm surface antigens is not altered by the fixation process.

CONCLUSIONS

The prevalence of ASAs in this population was 14%, while the prevalence of the control group was 2.5%. Of all factors analyzed only a history of vasectomy, an acute epididymitis, and an abnormal result in the bovine mucus penetration test was associated with elevated ASA titers (P < .001). In addition, we could demonstrate a time related formation of ASAs in men after vasectomy.

Evaluation of polyacrylamide gel as substitute for human cervical mucus in the sperm penetration test

OBJECTIVE

To compare polyacrylamide gel as synthetic medium with human cervical mucus (CM) for the in vitro sperm-penetration test during infertility investigation.

PATIENTS

One hundred sixty-nine randomly chosen couples with a median duration of infertility of 4 (range, 1 to 16) years presenting at the infertility unit of the Women's University Hospital of Heidelberg, Germany.

MAIN OUTCOME MEASURES

Evaluation of sperm migration in polyacrylamide gel used in four different concentrations (1.5%, 1.6%, 1.7%, 1.8%) in the capillary tube test in parallel with CM of patients' female partners and CM of fertile donors, obtained under standardized conditions. Correlation of migration test results with outcome of semen analysis including microbial cultures and testing for local antisperm antibodies by means of the mixed antiglobulin reaction, postcoital testing, and the subsequent pregnancy rate after control for female infertility factors in a prospective study.

RESULTS

Sperm ability to penetrate the synthetic medium (concerning all concentrations) correlated significantly with the penetration of human CM, although polyacrylamide proved to be a stronger barrier. Sperm velocity and duration of progressive motility were markedly reduced in polyacrylamide. Polyacrylamide results correlated with the outcome of standard sperm analyses but not with sperm antibody testing. No clear differentiation was obtained with regard to subsequent fertility (19% after 6 months), although adequate sperm migration in polyacrylamide 1.8% was significantly more frequent in the fertile group.

CONCLUSIONS

In analyzing the intrinsic motility, penetration testing with polyacrylamide gel provides important information not obtained by routine sperm analysis. However, particularly with regard to immunological factors and fertility prognosis, human CM should be preferred whenever possible.

Varicocelectomy: changes in Resazurin Reduction test

The Resazurin Reduction Test was performed on semen specimens from 27 patients with varicocele before and after varicocelectomy. The increases in both sperm concentration and motility were slight 3 months after surgery, but sperm concentration significantly improved 6 months after surgery (P < 0.01). The positive rate in the Resazurin Test significantly increased 3 and 6 months after surgery (each, P < 0.05) and the resazurin grade also increased at these times (each, P < 0.01). Of 13 patients with improved seminal findings, 7 had negative reactions during the preoperative Resazurin Test and 3 of these 7 patients continued to have negative reactions, while the other 4 had positive reaction after surgery. Of 14 patients with no improvement of semen characteristics, 6 continued to have negative reactions after surgery, but 4 with negative reactions before treatment showed positive reactions postoperatively. The Resazurin Test seems to assess fertility potential accurately after varicocelectomy.

Abnormal sperm-mucus penetration test predicts low in vitro fertilization ability of apparently normal semen

OBJECTIVE

To investigate whether Kremer's sperm-mucus penetration test may predict sperm fertilizing ability in IVF.

DESIGN

Kremer's test was prospectively performed on semen samples used for 66 consecutive IVF trials and compared with the fertilization rates and fertilization failure rates observed.

RESULTS

Fertilization rates were significantly reduced in cases of abnormal Kremer's test (42% versus 51%; n = 745 oocytes with a statistically insignificant increase in fertilization failure rates (21% versus 10%; n = 66 trials). For abnormal semen, fertilization rates (39% versus 39%; n = 208 oocytes) and fertilization failure rates (20% versus 28%; n = 17 trials) were similar regardless of Kremer's test result. For normal semen, an abnormal Kremer's test implied a significant decrease in fertilization rates (44% versus 54%; n = 537 oocytes) with a statistically insignificant increase in fertilization failure rates (21% versus 6%; n = 49 trials).

CONCLUSIONS

Abnormal Kremer's test results identify patients with a decreased in vitro fertilizing ability despite apparently normal semen samples and a group with very low fertilizing failure risk in case of normal semen samples and normal Kremer's test. Kremer's test does not add any predictive value to sperm analysis in the case of abnormal semen samples. These observations point out the importance of the male factor in fertilization failure even in the case of normal semen analysis.

Hypoosmotic swelling test with a medium of distilled water

The functional competence of the human sperm membrane is assessed by studying the swelling reaction of sperm when suspended in a medium of distilled water (water test). Eighty-seven patients with idiopathic infertility were investigated by the water test and the results were compared with various semen parameters. High correlations with the percentage of b-g type swollen sperm in the water test were observed for sperm concentration (r = .53, p < .05) and percent motility (r = .62, p < .01). The sperm swelling values obtained by the water test correlated well with those obtained by the hypoosmotic swelling test (HOST). Correlation coefficients in b-g and g swelling pattern were 0.89 and 0.71, respectively. The percentage of g-type swelling obtained by the water test was significantly larger than that obtained by the HOST (p < .05), although the two hypoosmotic procedures gave similar percentages of b-g swelling pattern. The percentage of g swelling pattern obtained by the water test correlated well with percent motility (r = .70, p < .001). These findings suggest that the water test is more useful for assessing the integrity of the sperm membrane than the HOST. The relationship between this test and subsequent fertility, as well as to other sperm function tests, needs further investigation.

Sperm motility should be assessed in fresh sperm and after a sperm washing procedure

A prospective study was carried out on semen samples from 118 consecutive unselected men attending our infertility clinic to determine whether sperm motility may be affected by seminal plasma. The incidence of asthenozoospermia as defined by fewer than 50% of spermatozoa with forward progressive motility in the untreated semen was 37.4%. This value was significantly reduced to 23% after washing and removing seminal plasma. Men with asthenozoospermia in untreated semen but normal in the washed sample had a percentage of normal sperm morphology and a percentage of swollen tails in the HOS test similar to those of controls, and higher than those of asthenozoospermics in both the untreated and washed sample. Sperm velocity was also significantly improved after the washing procedure. Spermatozoa selected by swim-down procedure and applied to a seminal plasma medium reduced sperm motility affecting negatively the HOS test. Sperm motility should be assessed after a sperm washing procedure, since seminal plasma contains constituents that decrease sperm motility without affecting membrane integrity.

Fertilization failure and dysfunctions as possible causes for human idiopathic infertility

Consideration of the most common currently practiced laboratory assays for human spermatozoal fertility are discussed, with reference to the relevance of such assays to success or failure in human in vitro fertilization (IVF). Such IVF therapy should be the definitive challenge for human spermatozoal fertilization ability. However, when fertilization fails, is polyspermic, or is suboptimal, then questions concerning the step or steps in the process of fertilization which are dysfunctional remain unanswered. Quite possibly new assays need to be devised to address these problems, while in the meantime our present laboratory assay systems need to be improved to discern those defects in fertilization which operate in many cases of human idiopathic infertility.

Relationship between hypoosmotic swelling test, semen analysis, and zona-free hamster ovum test

The hypoosmotic swelling test is a simple test for measuring the functional competence of the human sperm membrane. Fifty-four patients with idiopathic infertility were assessed by hypoosmotic swelling test and the results were compared with those of routine semen analysis and zona-free hamster ovum human sperm penetration test (ZSPT). Semen samples with abnormal semen parameters had lower percentage of swollen sperm in comparison with those with normal semen parameters. A positive correlation was observed between sperm concentration and sperm swelling (r = .50, p less than .05). A strong positive correlation was observed between the percentage of sperm motility and the percentage of swollen sperm (r = 0.60, p less than .01), and between motile sperm concentration and sperm swelling (r = .62, p less than .01). On the other hand, sperm swelling correlated only weakly with the percentage of sperm penetration. The results indicate that the hypoosmotic swelling test appears to evaluate different functional qualities of sperm than ZSPT.

Sperm motility index: a new parameter for human sperm evaluation

OBJECTIVE

The study was performed to evaluate the correlation between sperm motility index, a novel parameter of semen quality, and routine semen analysis parameters by microscopic evaluation.

DESIGN

Sperm motility index was measured by an electro-optical device, the Sperm Quality Analyzer (United Medical Systems Inc., Santa Ana, CA). Human semen samples covering the whole span of qualities were analyzed prospectively and simultaneously by both methods.

SETTING

Samples were collected from patients referred to university hospital infertility clinics.

PATIENTS, PARTICIPANTS

Nine hundred sixty-eight semen samples of 812 patients and healthy men were analyzed.

MAIN OUTCOME MEASURE(S)

Sperm motility index is a measurement of optical density fluctuations caused by motile cells; therefore, a positive correlation was anticipated between its values and semen motility parameters.

RESULTS

Sperm motility index values demonstrated statistically significant correlation with motile cell concentration, total cell concentration, and percent motile cells. They were also shown to reliably represent semen quality assessment obtained by two experienced andrologists.

CONCLUSIONS

The sperm motility index provides a reliable and objective reflection of semen motility parameters and quality.

The use of hens' egg white as a substitute for human cervical mucus in assessing human infertility

Semen samples from 179 patients with longstanding infertility were allowed to penetrate capillaries filled with a fraction of fresh hens' egg white (HEW) as a substitute for cervical mucus (CM) for the in-vitro sperm-cervical mucus penetration test (SCPMT). Results were correlated with those obtained from human CM (HCM) used in parallel on the same semen sample, compared to results of sperm analysis and post-coital testing (PCT) and analysed for their prognostic value for a subsequent pregnancy in a prospective study. The overall pregnancy rate after 6 months was 26.3% (47/179). Whereas routine semen analysis (semen volume, pH, sperm count, progressive motility, morphology and fructose concentration) did not differentiate between patients who achieved pregnancy and those who did not, significant differences were found for the penetration distance (P less than 0.02) and the motility grade of sperm in HEW (P less than 0.02). Although the mean sperm velocity in HEW was reduced compared to HCM, a close positive correlation was found between the sperm density and the penetration distance (P less than 0.001). The percentage of samples with good HEW penetration increased significantly in parallel with better results of post-coital testing (P less than 0.001). The results indicate that, when fresh human CM is not available, HEW can be used as a medium for the SCPMT as a valuable adjunct to semen analysis which provides information about sperm functional capacity.

An evaluation of the hypo-osmotic sperm swelling test as a predictor of fertilizing capacity in vitro

The ability of sperm to swell in hypo-osmotic conditions was examined in 211 semen samples from the partners of patients about to undergo oocyte retrieval for in-vitro fertilization (IVF). The test was performed using aliquots of semen, the remainder of which was then prepared for IVF. No significant difference was found, in either the percentage of swollen sperm or the type of swelling response, between samples that achieved fertilization in vitro and those that did not, or between any of the diagnostic categories of infertility (tubal damage, unexplained infertility, oligospermia). In samples which achieved fertilization in vitro there were correlations between sperm swelling and sperm motility (r = -0.51) and abnormal morphology (r = 0.33), but no such correlations were demonstrated in samples that failed to achieve fertilization. Moreover, there was no significant difference between the percentage of swollen sperm in semen (mean motility 64%), in samples immediately after preparation for IVF (mean motility 96%) or in capacitated sperm 24 h after preparation (mean motility 91%). These results demonstrate that the hypo-osmotic sperm swelling test does not assist in the prediction of the fertilizing capacity of human sperm in vitro.

Hypo-osmotic swelling test: analysis of prevasectomy ejaculates

The hypo-osmotic swelling (HOS) test was applied to 1,890 ejaculates obtained from previously fertile men who subsequently underwent a vasectomy. Less than 3% of the ejaculates produced an abnormal HOS test (less than 50% swelling), and more than 95% were normal (greater than or equal to 60% swelling). The sperm concentration and motility data were similar to those obtained by other investigators with prevasectomy ejaculates. Statistically significant but low correlation coefficients were present between the HOS test and these other sperm variables. On the assumption that the large majority of these men were fertile when the ejaculates were produced, the results support the contention that fertility is usually associated with normal or, occasionally, equivocal values in the HOS test.

Hypoosmotic swelling test of sperm

For the diagnosis and evaluation of the therapy for male infertility and for predicting the outcome of AIH and IVF-ET, technically simple, replicable tests that can be performed virtually anywhere and that have definite reliability are required. The results of the HOS test correlate well with the functions of the sperm cell membrane, indicating such aspects as motility, and it is thought to be a particularly effective test of human sperm fertility. Because the HOS test reflects the functions and integrity of the sperm cell membrane, it should be possible to use it to predict the potential for fertilization of frozen sperm.

Prognostic value of in vitro sperm penetration into hormonally standardized human cervical mucus

To analyze the prognostic value of the sperm cervical mucus penetration test (SCMPT), fresh semen samples of 99 male patients under infertility investigation were exposed to capillary tubes filled with freshly obtained cervical mucus (CM) of the patients' wives (WCM), fertile donors (DCM), and bovine CM (BCM). The quality of the human CM was standardized by oral administration of estrogens. The overall pregnancy rate after 6 months was 17.2% (17/99), and was significantly different in couples with poor and good SCMPT with WCM (1/44, 2.3% versus 16/55, 29%; P less than 0.001) in a prospective study. Human CM was superior to BCM as a penetration medium in providing more information about sperm function. The results suggest that in vitro sperm penetration testing with hormonally standardized CM of female partners adds an important dimension to sperm analysis with regard to fertility prognosis.

Diagnostic value of sperm function tests and routine semen analyses in fertile and infertile men

The results of routine semen analyses, the zona-free hamster oocyte penetration test, the hypoosmotic swelling test, and semen adenosine triphosphate levels were studied in 66 fertile and 130 infertile men. Multivariate discriminant analysis demonstrated that routine semen parameters including semen volume, sperm count, percent sperm motility, and percent normal spermatozoa in combination could predict the fertility of these patients with 70.4% accuracy. Of the three sperm function tests evaluated, the zona-free hamster oocyte penetration test and the hypoosmotic swelling test were selected by the multivariate discriminant analysis as variables capable of providing significant information on the fertility status of the patients. However, the addition of the results of these two tests to the routine semen analysis did not significantly improve the predictability of fertility. The overall correct prediction rate was 77.6% after incorporation of the results of these two sperm function tests. In this group of subjects, the presently available sperm function tests did not predict the fertility status of a patient with a high degree of accuracy.

Multivariate discriminant analysis of the relationship between the hypo-osmotic swelling test and the in-vitro fertilizing capacity of human sperm

Multivariate discriminant analysis was used to evaluate the usefulness of routine semen parameters and the hypo-osmotic swelling test (HOST) as predictors of the in-vitro fertilizing capacity of human sperm as assessed by the zona-free hamster egg penetration assay (HEPA). Eighty-eight semen samples from untreated patients attending an infertility clinic were analysed. Semen samples were classified into the following three groups before statistical analysis: group 1--positive sperm penetration (greater than or equal to 10%, n = 39); group 2--borderline penetration rates for HEPA (greater than 0% but less than 10%, n = 39) and group 3--negative sperm penetration (0%, n = 10). The percentage of sperm with normal morphology and sperm count were found to be significant in discriminating between semen samples exhibiting different in-vitro fertilizing capacity. These two discriminating variables in combination gave an overall correct classification rate of 45.5%. The multivariate discriminant analysis was also performed after excluding the data of group 2 semen samples (n = 39), which exhibited borderline sperm penetration rates. As a result, three discriminating variables including semen volume, sperm count and the percentage of sperm with normal morphology were selected. These three variables in combination could accurately predict whether a semen sample would exhibit positive sperm penetration (group 1) or negative sperm penetration (group 3) with an overall accuracy of 75.5%. The percentage of swollen sperm after hypo-osmotic treatment was not related to the HEPA result, as determined by linear correlation and multiple regression analyses, and did not give additional information about the in-vitro fertilizing capacity of sperm as evaluated by multivariate discriminant analysis.

Receiver-operating characteristics curves for semen analysis variables: methods for evaluating diagnostic tests of male gamete function

This study draws on decision analysis to estimate the utility of seminal variables in predicting pregnancy. The infertile couples selected (n = 709) excluded those who had donor insemination or known female factors (history of pelvic infection, ovulatory disorders, endometriosis, and tubal disease). Diagnostic test properties were calculated with respect to pregnancy for two variables derived from the semen analysis report: sperm density, and the total number of motile sperm in the ejaculate (TMS). Receiver-operating characteristic (ROC) curves based on sensitivity and specificity revealed that none of the proposed thresholds for sperm density or TMS is clearly a best choice. The highest positive predictive values for sperm density (75%) and TMS (75%) were associated with cutoff points at five million sperm per milliliter and five million motile sperm per ejaculate, respectively. The false positive rates when these cutoff points were used were 4.3% (sperm density) and 5.6% (TMS). ROC analysis provides visual and numeric evidence of the quality of a diagnostic test and constitutes a set of procedures for incorporating information from new tests of male gamete function into the diagnostic assessment of infertility.

TEST-egg yolk buffer storage increases the capacity of human sperm to penetrate hamster eggs in vitro

A total of 85 semen samples from infertility clinic patients were examined to study the effect of storage at 4 degrees C in TES-Tris (TEST)-egg yolk buffer for 24 h on the penetrating capacity of sperm in the zona-free hamster egg penetration assay (HEPA). The mean sperm penetration rate and the fertilization index increased significantly after storage in TEST-egg yolk buffer. Only five out of the 85 samples (5.9%) failed to show any improvement in sperm penetration rate after cold storage. The sperm penetration rate before cold storage showed no significant correlations with routine semen characteristics, semen ATP concentration or the functional integrity of sperm membranes as measured by the hypo-osmotic swelling technique. Significant but low correlations were observed between sperm penetration rate after cold storage and the following semen parameters: sperm count, % motility, total number of motile sperm, % normal sperm morphology, total number of normal sperm, semen ATP concentration and sperm penetration rate before cold storage. Partial correlation analysis revealed that the positive correlation between semen ATP concentration and sperm penetration rate after cold storage was not a direct relationship but was due to the correlation with sperm count. The combination of sperm penetration rate before cold storage, sperm count and % normal sperm morphology accounted for 26.2% of the variation in sperm penetration rate after cold storage by stepwise multiple regression analysis, while sperm penetration rate before cold storage alone explained 13.5% of the variation. The results indicate that TEST-egg yolk buffer treatment can enhance sperm penetration rate in vitro and may be useful in the treatment of impaired sperm fertility.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved sperm counts in mink males (Mustela vison) treated with clomiphene citrate

A group of 12 sterile, azoospermic mink males were treated with clomiphene citrate (10 mg/kg/day) for 10 days during the mating season; 50% of the males showed improved sperm counts already after 2 days of treatment and the maximum effect was seen 4-6 days after the start of the treatment. The other half of the group did not respond to the treatment and their sperm counts remained near zero during the whole experiment.

Correlation between human sperm swelling in hypoosmotic medium (hypoosmotic swelling test) and in vitro fertilization

Human ejaculates (n = 83) were analyzed for standard sperm parameters (concentration, motility, and morphology), as well as for the ability of the spermatozoa to react (swell) in a hypoosmotic medium (Jeyendran et al, 1984). Subsequently, the fertilizing capacity of the spermatozoa was tested by their ability to fertilize human oocytes in vitro. Although the sperm concentration was adjusted for in vitro fertilization, no adjustments were made for sperm motility and morphology. Correlation of the in vitro fertilizing capacity of the spermatozoa with the hypoosmotic swelling test (r = 0.56) was much higher than with standard sperm parameters (r varied from -0.04 to 0.25). Complete overlap was noted with standard semen parameters whether the ejaculate did or did not fertilize oocytes and ranged from very low to very high values in both cases. By contrast, all the semen samples that fertilized oocytes showed a 60% or higher reaction in the hypoosmotic swelling test, whereas the majority of the "infertile" semen samples showed less than 60% swelling. It therefore appears that, under the conditions of our studies, the hypoosmotic swelling test is a more accurate predictor of successful in vitro fertilization outcome than the conventional semen parameters. A combination of all parameters, however, is likely to be most useful. The hypoosmotic swelling test is simple and economical, and it is recommended that this test be further scrutinized for its value as an additional tool in the assessment of the in vivo fertilizing capacity of ejaculated spermatozoa.

Spermatozoal fertilizing capacity in polyzoospermia: a preliminary study

Men with the spermatological symptom of polyzoospermia (greater than 250 X 10(6) sperm/ml) have been reported to seldom impregnate their wives. It was the aim of this study to investigate the spermatozoal fertilizing capacity in polyzoospermia by the human sperm and zona-free hamster ova penetration bioassay. General semen characteristics and in vitro spermatozoal fertilizing capacity were studied in 12 polyzoospermic male partners of couples of infertile marriages. The results were compared with those from a control group of normospermic fertile men (n = 22). No significant differences in sperm motility, normal morphology and in vitro spermatozoal fertilizing capacity were found between the two groups. The polyzoospermic men we studied did not appear to have any defect with the spermatozoal fertilizing capacity, as assessed by the heterologous sperm--ova penetration bioassay. The apparent impairment of fertility and higher abortion rate in couples with polyzoospermic male partners, as described in the literature, may be related to chromosomal aberrations and/or other unknown functional defect of the spermatozoa.

The relationship between the human sperm hypoosmotic swelling test, routine semen analysis, and the human sperm zona-free hamster ovum penetration assay

The functional integrity of sperm membranes of 270 semen samples collected from fertile men and the male partners in couples with infertile marriages was assessed by the hypoosmotic swelling test and the results correlated with routine semen analysis and the human sperm zona-free hamster ovum penetration assay. Semen samples with abnormal semen parameters had lower values of percentage of swollen sperm after hypoosmotic treatment in comparison with those with normal semen parameters. A weak positive correlation was observed between sperm swelling and sperm morphologic features (r = 0.32, P less than 0.05) and between sperm swelling and sperm motility (r = 0.22, P less than 0.05). Insignificant correlation was observed between sperm swelling and in vitro sperm fertilizing capacity, as assessed by the zona-free hamster ovum penetration assay. The results indicate that the sperm swelling test and the zona-free hamster ovum penetration assay are evaluating different functional qualities of sperm that are apparently not associated with each other.

Computer-assisted measurement of sperm swimming speed in human semen: correlation of results with in vitro fertilization assays

A semiautomatic computerized technique for the measurement of sperm swimming speed is presented. The equipment is easy to use and would be suitable for routine clinical laboratories. The value of the sperm speed measurements obtained from over 100 individuals in relation to fertility has been studied by the correlation of these results with human in vitro fertilization (IVF) data and sperm penetrating capability in the zona-free hamster egg assay. The results show that sperm speed measurements correlate very well with those of the IVF, both human and hamster, and can be used successfully, in conjunction with multivariate statistical methods, to predict the outcomes of such techniques with about 75% accuracy.