Proven Fertile Men Research Articles

Relationship between fertilizing ability of ejaculated human spermatozoa and its chromatin heterogeneity

Objective: The aim of this study was to examine the relationship between the fertilizing ability of ejaculated human sperm and its chromatin heterogeneity.Methods: We used the D‐AO staining method (acridine orange epifluorescence accompanied by diamide, a thiol oxidizing agent) to analyze the sperm chromatin structure of infertile patients with IVF‐ET treatment. SDS‐PAGE was performed to analyze the sperm nuclear proteins collected from patients with immature sperm (stained red with D‐AO staining) and proven fertile men.Results (1) It was suggested that D‐AO staining allowed the immature sperm to be divided into two groups. One was immature sperm, which had disturbance of S‐S formation in the epididymides, and the other was that which had an abnormal exchange process of nuclear proteins in the testes. (2) The stainability after D‐AO staining showed no correlation with the findings of semen analysis. (3) The fertilization rate of IVF‐ET was significantly correlated to the percentage of green sperm staining with D‐AO staining. (4) In the pregnant group after IVF‐ET, it was noticed that sperm of the green type with D‐AO staining was increased in comparison with the non‐pregnancy group. (5) The fertilization rate in the group of the sperm stained red with D‐AO staining was increased to 73.5% by ICSI. (6) Definite differences were noticed between the protein components of the patients with immature sperm and those of the proven fertile men by analyzing with SDS‐PAGE.Conclusion D‐AO staining was an efficient method for evaluating the fertilizing ability of human ejaculated sperm, and to determine an appropriate ART tool such as ICSI.

Time to pregnancy in relation to semen quality assessed by CASA before and after sperm separation

In order to provide a reference for infertile men, we defined normal values of semen quality in a population of fertile men, using computer-assisted semen analysis (CASA) before and after sperm separation. Additionally, we investigated the relationship between semen quality and time to pregnancy (TTP). Semen samples were obtained from 315 proven fertile men. The median sperm concentration in fresh samples was 107 x 10(6)/ml (5-95 percentiles: 16-322 x 10(6)/ml), the median percentage of motile sperm cells was 65% (14-87%) and the median percentage of progressively motile cells was 37% (5-64%). After density gradient sperm separation, the median total sperm count was 46 x 10(6) (4-350 x 10(6)), the median percentage of motile sperm cells was 77% (16-95%) and the median percentage of progressively motile cells was 63% (11-84%). No significant associations were found between TTP and sperm counts or sperm motility, either before or after sperm separation. This may be due in part to the fact that the study comprised couples with proven fertility. We have defined semen parameters, including the results of density gradient separation, in a population of normal fertile men which may be of interest in the evaluation of semen samples from infertile men.

Effect of vasectomy on P34H messenger ribonucleic acid expression along the human excurrent duct: a reflection on the function of the human epididymis.

Sperm surface proteins involved in fertilization can be added or modified during epididymal transit. P34H, a human epididymal-sperm protein, appears on the sperm acrosomal cap in the distal caput-proximal corpus epididymis. In previous studies, it was shown that P34H is present on spermatozoa in men of proven fertility, is absent in 50% of men presenting with idiopathic infertility, and that a high proportion of men with normospermic vasovasectomy produce spermatozoa deficient in this sperm surface protein. P34H mRNA was expressed in the principal cells of the epididymis of normal men, predominantly in the corpus region. Recently, results coming from the assisted reproductive technologies have questioned the importance of the human epididymis in sperm maturation. In order to understand the effect of obstruction on the physiological state of the human epididymis and its function in sperm maturation, we have analyzed the expression of P34H mRNA at the level of the vas deferens and along the epididymis of normal and vasectomized men. In situ hybridization experiments showed that obstruction of the vas deferens alters the pattern of P34H mRNA expression compared with the tract of normal tissues. The P34H transcript was detected in the proximal caput epididymis of vasectomized men at a much higher intensity than that observed in the same region of normal tissues, being restricted to the principal cells of the epididymal epithelium. Compared with the normal duct, the lumen of vasectomized men was distended throughout the duct and the height of the epithelium was maximal in the caput. P34H mRNA was detectable in vas deferens, was not affected by vasectomy, and a 912-base pair P34H transcript was restricted to the epithelial cells of the vas deferens. Thus, using P34H as a marker, these results show that vasectomy alters the pattern of gene expression along the human epididymis, and suggest that the vas deferens can be a major contributor to sperm maturation in certain situations.

Alterations in sperm characteristics of follicle-stimulating hormone (FSH)-immunized men are similar to those of FSH-deprived infertile male bonnet monkeys.

The quality of sperm ejaculated by bonnet monkeys and normal, healthy proven fertile volunteer men, both actively immunized with ovine follicle-stimulating hormone (oFSH), was examined at different times of study for chromatin packaging and acrosomal glycoprotein concentration by flow cytometry. Susceptibility of sperm nuclear DNA to dithiothreitol (DTT)-induced decondensation, as measured by ethidium bromide binding, was markedly high compared with values at day 0 in men and monkeys during periods when FSH antibody titer was high. Sperm chromatin structure assay yields alphat values, which is another index of chromatin packaging. Higher alphat values, signifying poor packaging, occurred in both species following immunization with heterologous pituitary FSH. The binding of fluorosceinated pisum sativum agglutinin (PSA-FITC) to acrosome of sperm of monkeys and men was significantly low, compared with values at day 0 (control) during periods when cross-reactive FSH antibody titer was high and endogenous FSH was not detectable. Blockade of FSH function in monkeys by active immunization with a recombinant oFSH receptor protein corresponding to a naturally occurring messenger RNA (mRNA) also resulted in production of sperm with similar defects in chromatin packaging and reduced acrosomal glycoprotein concentration. Thus, it appears that in monkeys and men, lack of FSH signaling results in production of sperm that exhibit defective chromatin packaging and reduction in acrosomal glycoprotein content. These characteristics are similar to that exhibited by sperm of some class of infertile men. Interestingly, these alterations in sperm quality occur well ahead of decreased sperm counts in the ejaculate.

Poor quality of sperm as it affects repeated early pregnancy loss.

A study was carried out to determine whether males contribute to repeated early pregnancy loss. Semen samples were analyzed from proven-fertile men (n = 51 group I) and from men whose partners presented with early pregnancy loss (>3 first trimester abortions, n = 32 group II). Routine analysis, sperm function tests, and ultrastructural studies of sperms were carried out. Female factor could be identified in 25 (78%) couples, and in 7 (22%) no cause either male or female could be identified and the semen analysis was normal. Percent morphologically normal did not differ significantly between the groups, but increased sperm head abnormalities were seen. The functional tests were all normal except for a significant decrease in the capacity of nuclear chromatin to decondense in vitro. The ultrastructural studies showed defects of chromatin condensation and irregular nuclei with vacuoles. This study points to the loss of chromatin integrity as a possible contributing factor from males to early pregnancy loss.

Microdeletion of the DAZ (deleted in azoospermia) gene or the YRRM (Y chromosome ribonucleic acid recognition motif) gene does not occur in patients with Klinefelter’s syndrome with and without spermatogenesis

Objective: To evaluate the occurrence of microdeletions of the Y chromosome involving the DAZ and YRRM genes in patients with Klinefelter’s syndrome with and without spermatogenesis. Design: Controlled clinical study. Setting: Yamagata University Hospital, Yamagata, Japan. Patient(s): Patients with Klinefelter’s syndrome with spermatogenesis (n = 1) and without spermatogenesis (n = 20) and a control group of men of proven fertility (n = 10). Intervention(s): Blood and semen sampling and testicular biopsy. Main Outcome Measure(s): Semen analysis, polymerase chain reaction amplification of 32 DNA loci on the long arm of the Y chromosome involving the DAZ (deleted in azoospermia) and YRRM (Y chromosome ribonucleic acid recognition motif) genes, and measurement of plasma FSH, LH, and testosterone levels. Result(s): No microdeletions of 32 loci were found in any of the patients with Klinefelter’s syndrome, either with or without spermatogenesis. Plasma LH and FSH levels were abnormally high and testosterone levels were reduced in all the patients with Klinefelter’s syndrome. Conclusion(s): Severe impairment of spermatogenesis in patients with Klinefelter’s syndrome is not caused by microdeletions of the Y chromosome involving the DAZ and YRRM genes.

Some vasovasostomized men are characterized by low levels of P34H, an epididymal sperm protein.

During epididymal transit, sperm surface proteins involved in the fertilization process can be added or modified. P34H, a human epididymal-sperm protein, is proposed to be involved in the interactions between spermatozoa and the zona pellucida. We have previously demonstrated that P34H is present in men of proven fertility and is absent in 50% of men presenting with idiopathic infertility. Spermatozoa with a low amount of P34H exhibit a dramatic reduction in their ability to interact with zona pellucida. Even if the surgical success of vasectomy reversal is high, fertility is not always reestablished, possibly due to epididymal damage caused by vasectomy. In this study, western blot analyses were performed to determine the level of P34H present on spermatozoa of men who underwent vasectomy reversal. Spermatozoa obtained from different semen samples from a given individual had similar P34H levels; however, samples from different men were highly variable. When quantified by densitometric scanning, P34H levels from vasovasostomized men varied between 1.5% and 149% compared with that from a fertile donor who represented 100%. Eighteen of 25 vasovasostomized men had a P34H level lower than 30% of the normal value, while the remaining 7 males were in the normal range. Furthermore, the population of vasovasostomized men with P34H levels lower than 30% was significantly different from the control group of 19 fertile men. The high variation of P34H levels observed in vasovasostomized men did not correlate with the spermiogram values (P > 0.05). An important factor in determining sperm P34H level appears to be the period of time elapsed between the vasectomy and vasovasostomy. In summary, our results show that the P34H level varied from one man to another and that low levels of the epididymal sperm protein is associated with vasectomy reversal.

Altered luteinizing hormone pulsatility in infertile patients with idiopathic oligoasthenozoospermia.

In a previous study, we demonstrated that oligoasthenozoospermic (OAZ) patients had two types of testosterone response to human chorionic gonadotrophin (HCG) administration: group 1 (OAZ-1) had an altered, monophasic (no first peak) response, and group 2 (OAZ-2) had a normal biphasic response. The objective of the present work was to study the luteinizing hormone (LH) pulsatility in OAZ-1 compared with both OAZ-2 and men of proven fertility (PF), in order partly to determine the possible aetiology of the blunted acute testosterone response to HCG in these patients. LH pulsatility was measured in 10 PF, 10 OAZ-1 and 10 OAZ-2 patients, in blood samples taken every 5 min for 6 h in PF, and for 4 h in OAZ patients. LH values were determined by a time-resolved immunofluorometric assay. Frequency and amplitude of the LH pulses were determined by a computer program. LH pulse frequency, expressed as pulses/4 h, was significantly lower in OAZ-1 (1.5+/-0.97) than in PF (2.4+/-0.63) and OAZ-2 (2.4+/-0.84) patients. In six OAZ-1 and two OAZ-2 patients, LH pulsatility was diminished, as they showed less than two pulses/4 h. No statistically significant differences in LH pulse amplitude were found. These results, together with a higher number of OAZ-1 cases found with decreased LH pulsatility, suggest that, at least in a subset of these men, quantitative and/or qualitative alterations of LH secretion might have occurred.

Comparison of gonosomal aneuploidy in spermatozoa of normal fertile men and those with severe male factor detected by in-situ hybridization.

The purpose of the study was to analyse the frequency of sex-chromosome numerical abnormalities in human spermatozoa of infertile men by using a standardized experimental protocol of double target in-situ hybridization (ISH). The experiments were performed on decondensed sperm heads from 15 infertile patients (six cases of unexplained infertility and nine cases of severe oligoasthenoteratozoospermia). Three men of proven fertility were used as controls. The probes employed recognized the centromeric regions of human X chromosome and the long arm of the Y chromosome. In a smaller number of cases, additional experiments of double ISH were performed using centromeric probes for chromosomes 1 and 17. Signal detection was based on protocols of enzymatic cytochemical reactions. A total of 24,508, 24,679 and 42,285 cells were scored in the control, unexplained infertility and severe male factor groups of patients respectively. In all the patients in the ISH efficiency result was approximately 98%. In controls, unexplained infertility and severe male factor patients, the frequency of morphologically normal sperm cells carrying an abnormal chromosome constitution (XX or YY or XY or > 2 sex chromosomes signals) was 0.86, 0.75 and 1.35% respectively. The value of this last group of patients (severe male factor) was significantly higher than in the other two groups of patients (P < 0.008). The same findings were made using the autosomic probes. Our preliminary data support the possibility of an increased risk from paternal origin sex chromosome aneuploidies in children born after intracytoplasmic sperm injection (ICSI). Further investigations of the cytogenetic constitution of spermatozoa from severe male factor patients is warranted.

Cases of Human Infertility are Associated with the Absence of P34H, an Epididymal Sperm Antigen1

The interaction of spermatozoa with the zona pellucida is a critical step of fertilization. Specific sperm surface proteins involved in this process can be added or modified during epididymal transit. We have previously described a 34-kDa human epididymal sperm protein (P34H) that we proposed to be involved in sperm-zona pellucida interaction. In this study, Western blot analysis were performed to determine the level of P34H protein present on the spermatozoa of 16 men with idiopathic infertility. These levels were compared with the amount of P34H protein found in men of proven fertility. In addition, a sperm-zona pellucida binding assay was performed with spermatozoa from fertile and infertile men. Spermatozoa obtained from different semen samples from a given individual had similar P34H levels. However, the amount of P34H varied from one man to another. Nine of 16 infertile men had a P34H level that was less than 30% of the normal value based on a population of fertile men, while the remaining 7 males were in the normal range. Sperm from infertile subjects with a normal P43H determination bound to zonae pellucidae as efficiently as those from controls. However, spermatozoa from subjects with a low amount of P34H exhibited a dramatic diminution in their ability to interact with zonae pellucidae. Our results show that the quantity of the epididymal protein P34H varied from one male to another and that low levels of this epididymal sperm protein are associated with certain cases of idiopathic infertility. Results are discussed with regard to the function of human epididymis in sperm maturation.

The value of subcellular elemental analysis in the assessment of human spermatozoa

The conventional sperm parameters of concentration, motility and morphology are descriptive and have proved of little value in predicting the fertilization potential of semen. New complementary tests of sperm function are required. Previous studies evaluating the subcellular elemental composition of spermatozoa using X-ray microanalysis with electron microscopy suggested that this technique may have the potential to confirm spermatozoal intracellular normality. This study compares the semen from 18 men of subfertile relationships and from 10 men of proven fertility with reference to concentration, motility, morphology and the elemental composition of spermatozoa. The elements phosphorus, sodium, potassium, chlorine and sulphur were detected and there were large intra- and intersample variations in the concentrations of these elements. There was no statistically significant difference in the elemental composition between the two groups. This study suggests that the spermatozoa of fertile and subfertile men are similar in subcellular elemental composition and in the maintenance of an ionic gradient. This test is therefore not a useful predictor of sperm function.

Detection of monocyte chemotactic and activating factor (MCAF) and interleukin (IL)-6 in human seminal plasma and effect of leukospermia on these cytokine levels.

To demonstrate whether monocyte chemotactic and activating factor (MCAF) and interleukin-6 (IL-6) are present in the seminal plasma, and whether these presence is modulated by leukospermia. Semen samples from 53 men were obtained by masturbation and examined for the presence of MCAF and IL-6 by enzyme immunoassay (EIA). Semen samples were obtained from 28 infertile men without leukospermia, 16 infertile men with leukospermia, and nine proven-fertile men. The correlation between the amount of MCAF in the seminal plasma with some spermiogram parameters and other cytokines such as IL-6 and IL-8 was statistically evaluated. Immunoreactive MCAF was detected in the seminal plasmas of all 53 subjects. The MCAF titer in the seminal plasma of patients with leukospermia (11.19 +/- 2.75 micrograms/l) was significantly higher than that in the seminal plasma of the patients without leukospermia (3.24 +/- 0.53 micrograms/l) and the fertile men (2.78 +/- 0.35 micrograms/l) (P < 0.001). The IL-6 titer in the seminal plasma of the patients with leukospermia (21.05 +/- 4.49 ng/l) was also significantly higher than that in the seminal plasma of the patients without leukospermia (8.77 +/- 1.92 ng/l) and the fertile men (6.94 +/- 1.27 ng/l) (P < 0.01). There was a high degree of correlation among the levels of MCAF, IL-6 and IL-8 in the seminal plasma. These findings demonstrated the presence of MCAF and IL-6 in the seminal plasma, and that the levels of these cytokines were elevated in the seminal plasma of the infertile patients with leukospermia.

SERUM ESTRADIOL LEVELS IN NORMAL MEN AND MEN WITH IDIOPATHIC INFERTILITY

Serum estradiol levels were measured in 360 men attending an infertility clinic and 68 proven fertile men to determine whether estradiol measurements are clinically useful. The normal range of estradiol levels found in fertile men was 10-82 pg/ml. Serum concentrations of estradiol in azoospermic or oligozoospermic patients were significantly lower than those in normozoospermic men (p < 0.021). Serum concentrations of testosterone were also significantly decreased in infertile patients (p < 0.025). This decrease in serum estradiol may be partly due to reduced testosterone levels in these men because estradiol is mainly formed by peripheral aromatization of testosterone in fatty and muscle tissues. However, the exact mechanism for the decrease in the serum estradiol levels remains undetermined. It is concluded that serum estradiol levels are significantly low in the men with various testicular disorders.

Sperm-zona pellucida binding of human sperm is correlated with the immunocytochemical presence of proacrosin and acrosin in the sperm heads but not with the proteolytic activity of acrosin

To determine whether the sperm-zona pellucida (ZP) binding is related to the presence of immunoreactivity for proacrosin and acrosin and/or to the proteolytic activity of acrosin. The Andrology Clinic, University of L'Aquila, Italy. Thirty-five infertile couples and 15 men of proven fertility. Salt-stored unfertilized oocytes after IVF were inseminated with a mixture of equal numbers of test and fertile donor sperm after swim-up selection, respectively labeled with fluorescein or rhodamine. Total acrosin activity, the percent of sperm immunostained for proacrosin and acrosin, and the percent of sperm with oval heads were evaluated in fresh semen and after swim-up selection. Three zonae were used for each patient and sperm-ZP binding ratio (ZP ratio) was calculated as the total number of test sperm bound to ZP divided by the total number of control sperm bound to ZP. The ZP ratio was compared with the percent of live sperm immunostained for proacrosin and acrosin, with total acrosin activity and with the percent of sperm with oval heads after swim-up selection. The sperm-ZP binding ratio was correlated positively with the percent of sperm immunostained for proacrosin and acrosin and with the percent of sperm with oval heads, but not with acrosin activity. Ejaculates with immunostaining for proacrosin and acrosin > or = 55% of sperm (the mean value of infertile couples) and acrosin activity < 24 muIU/10(6) sperm (the mean value of infertile couples) (n = 8) had a ZP ratio > or = 0.5, whereas ejaculates with low immunostaining for proacrosin and low acrosin activity (n = 12) had a ZP ratio < 0.5. The difference between the ZP ratio of the two groups was highly significant. The ZP binding is related to the immunocytochemical presence of proacrosin and acrosin but not to the proteolytic activity of acrosin in human sperm, suggesting that egg recognition and proteolytic activity are independent functions of proacrosin and acrosin.

A quantitative study of sperm head ultrastructure in subfertile males with excess sperm precursors

To make an objective comparison between sperm head ultrastructure in fertile subjects and a subfertile cohort with an excess of immature germinal elements in the ejaculate. A quantitative analysis of ultrastructural features of the sperm head using transmission electron microscopy in the defined groups. Ten men of proven fertility as controls and 10 subfertile subjects with a persistent excess of sperm precursors in the ejaculate were investigated. The Infertility Clinic at Queen Charlotte's and Chelsea Hospital, London. Each individual in the study achieved a score for a range of previously defined features of sperm head ultrastructure. These scores provided the basis for comparison between fertile and subfertile subjects. Subfertile individuals were found to have motile sperm with significantly more hypoplastic, detached, and abnormally shaped acrosomes than fertile controls. Sperm nuclei in these subjects also contained significantly more intranuclear vacuoles and immature chromatin and were associated more commonly with cytoplasmic droplets than fertile controls. Men with an excess of sperm precursors in the ejaculate have motile sperm with a range of abnormalities involving the nucleus and acrosome to account for reduced functional competence.

Ultrastructural changes in the efferent duct and epididymis of men with obstructive infertility

Ultrastructural changes in the efferent duct and in different regions of the epididymis in men with obstructive azoospermia were compared with corresponding tissues collected from men of proven fertility who underwent castration due to malignancy of the prostate. Major degenerative changes were seen in the efferent duct and the caput epididymidis of men with obstruction at the caput epididymidis which may have been induced by fluid pressure due to defective absorption of testicular fluid in the caput epididymidis. These degenerative changes included decrease in tubular and lumen diameter of the caput and the cauda epididymides, decrease in height of the stereocilia, reduction in rough endoplasmic reticulum and Golgi material, and presence of lipofuscin and osmiophilic dense bodies. The degenerative changes were less when the site of obstruction was in the cauda epididymidis since fluid reabsorption would continue to take place normally in the caput epididymidis. In men who had undergone vasoepididymostomy (VEA), the ejaculated spermatozoa showed a high percentage of morphological abnormalities which may have occurred due to adverse effects of long-term obstruction on spermatogenesis.

Detection of interleukin-8 (IL-8) in seminal plasma and elevated IL-8 in seminal plasma of infertile patients with leukospermia

To determine if interleukin-8 (IL-8) is a normal constituent of seminal plasma and if leukospermia is a factor determining its elevation. Seminal plasma from 58 men obtained by masturbation was examined for the presence of IL-8 using an IL-8 specific sandwich ELISA. Semen samples were obtained from 34 infertile men without leukospermia, 10 infertile men with leukospermia, and 14 proven fertile men. The correlation of amount of IL-8 in seminal plasma with some spermiogram parameters and the amount of polymorphonuclear (PMN) elastase was statistically evaluated. Immunoreactive IL-8 was observed in the seminal plasma of all 58 subjects. The IL-8 titer in seminal plasma of patients with leukospermia (6.16 +/- 0.82 micrograms/L) was significantly higher than that in seminal plasma of patients without leukospermia (2.35 +/- 0.34 micrograms/L) and fertile men (1.64 +/- 0.29 micrograms/L). There was a high degree of correlation between PMN elastase and IL-8 levels in seminal plasma. These findings demonstrate IL-8 to be in seminal plasma and elevated IL-8 levels in infertile patients with leukospermia.

Superovulation fails to increase human blastocyst yield after uterine lavage

Uterine lavage affords the potential for non-invasive human blastocyst recovery, with obvious potential for preimplantation genetic diagnosis. In an effort to duplicate in women the multiple blastocyst recovery per cycle that can be achieved in several other species, we initiated a programme in which fertile women underwent superovulation, followed by lavage and embryo collection. We superovulated 15 fertile women, aged 21-40, in 29 cycles using one of four regimens. Insemination was by either intercourse or artificial intracervical donor insemination with cryopreserved sperm from men of proven fertility. In 28 of 29 cycles, the uterus was lavaged daily for 1, 2, or 3 days between 5 and 10 days after human chorionic gonadotropin (hCG) administration or luteinizing hormone (LH) surge. Almost total fluid volume was recovered in every lavage. There were no retained pregnancies and no complications. Surprisingly, only two morulae, one blastocyst, and four unfertilized ova were recovered. Thus, alterations in ovulation induction, insemination timing, or lavage techniques must be contemplated in order to increase the blastocyst yield and thus fulfil the potential of uterine lavage for preimplantation diagnosis.

Sperm Motility, Velocity and Migration

Four different methods for evaluating sperm motility were analysed for experimental error: subjective assessment of a wet film preparation, sperm velocity measured by time-lapse photography, sperm velocity measured by computer analysis and sperm migration across a nucleopore membrane. Subjective assessment of motility was found to be inaccurate, within single observer and between 2 observers. Both methods of measuring mean sperm velocity were accurate, particularly that using the computer analysis system; a high technical failure rate was found using time-lapse photography. Sperm migration across a nucleopore membrane was found to be highly inaccurate. Two groups were then analysed for the predictive value of these tests (excluding sperm migration): 104 proven fertile men and 53 infertile men. Although subjective motility was able to predict from which group the sample came at optimum cut-off with 78% accuracy, computer analysed sperm velocity could predict with overall 91% accuracy at optimum cut-off. Computer analysis of sperm velocity offers a rapid, objective and predictive assessment of sperm function.

Sperm Density Measurement: Should this be Abandoned?

Sperm density measurement by means of the Makler chamber was performed on a single semen specimen from 2 groups: 104 proven fertile men and 53 infertile men; 11.5% of the fertile population had a sperm density less than 20 million/ml (median 84, mean 91.3, SD 60.5) and 33% of the infertile population had a sperm density greater than 20 million/ml (median 10, mean 26.9, SD 34.8). There was a statistically significant difference in median between the 2 groups, but when a discriminant analysis was applied, sperm density could predict fertile status with only 68% accuracy at optimum cut-off. Sperm density is valueless in distinguishing fertile from infertile men and is neither useful in diagnosis nor in monitoring the progress of treatment for male infertility. It should be abandoned as a quotable measurement of male fertility.