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In this study the frequency distribution of sperm counts and total sperm counts from more than 4000 allegedly fertile males were compared with those of husbands in 1000 infertile couples. Significant differences were observed only at the lower end of the scale (sperm counts below 10 million/ml and total sperm counts below 25 million/ejaculate). Frequency distributions of sperm counts above 10 million/ml or total sperm counts above 25 million/ejaculate revealed little difference between the fertile and infertile groups. These data suggest that, unless other parameters are found to be abnormal, sperm counts and total sperm counts above 10 million/ml and 25 million/ejaculate, respectively, probably are not major factors in a couple's infertility.
The relationship between the three basic parameters of ejaculated spermatozoa, i.e. concentration, motility and morphology, and the results of intracytoplasmic sperm injection (ICSI) were investigated in 838 microinjection cycles. A further 123 ICSI treatment cycles in which testicular spermatozoa were used for microinjection were also evaluated. The influence of anti-sperm antibodies (ASA) on the outcome of ICSI was investigated by analysing 55 cycles where the proportion of ASA-bound spermatozoa was > or =80%. After microinjection, oocyte intactness, fertilization, embryo cleavage, transfer and pregnancy rates were recorded and compared. The results showed that neither the type nor the extent of sperm impairment had an important influence on the outcome of ICSI when ejaculated spermatozoa were used. Only two very rare conditions had a strongly negative influence on the result of ICSI, i.e. where immotile (presumably dead) spermatozoa or where round-headed spermatozoa were injected into the oocyte. Neither the proportion of ASA-bound spermatozoa, the type of dominantly present ASA, nor the location of ASA on the spermatozoa had an important influence on fertilization, embryo development or pregnancy rates after ICSI. In most of the cycles combined with testicular biopsy (79%), there were enough motile spermatozoa present in the wet preparation for injection of all the oocytes. Injection of motile testicular spermatozoa led to a higher normal fertilization rate than did injection of non-motile spermatozoa (65 versus 21%). It can be concluded that injection of motile (living) spermatozoa into oocytes is the most important factor in determining good results with ICSI and that other sperm parameters do not have a strong influence on the outcome of ICSI.
The sperm count and morphology, and testicular histopathology were studied in mice over a period of 75 days following a single oral administration of 50, 100, and 200 mg/kg N.N'-methylene-bis-acrylamide (MBA). With a 50 and 100 mg/kg dose, the sperm abnormality reached a maximum at 30 days, whereas the sperm count reached a minimum at 35 days. The abnormality and decrease in sperm count were both dose dependent. Following the administration of 200 mg/kg MBA, the appearance of abnormal sperm showed a diphase pattern, i.e., first at 7-15 days without any reduction of the sperm count and second at 30 days after treatment. Testicular histopathological changes showed that resting spermatocytes, succeeding leptotene and zygotene spermatocytes were either absent or reduced 1-3 days after treatment with 200 mg/kg MBA. These early histopathological changes seemed to precede both the increase in abnormal sperm and the decrease in sperm count observed 30-35 days post-treatment, and also suggested that resting spermatocytes were most sensitive to MBA exposure among various spermatogenic cells.
The objective of the studies was to evaluate infertility according to sperm count shifts. The distribution of the sperm count of 1024 Danish men (median 56 million/ml) served as reference. The data were transformed with multiplicative or additive models to create alternative distributions with median sperm count values changed by 25-100%. Sperm-count-specific fecundabilities were provided from a follow-up of first-pregnancy planners in a Danish population. The estimated average fecundability of the 1024 Danish men was 16.9% [95% confidence interval (95% CI) 16.7-17.2], and the proportion of cohabiting men with spouses pregnant within 1 year was 86.0% (95% CI 84.1-87.8). Simulations of alternative sperm count distributions indicated that the relationship between sperm count shift and fertility strongly depends on the median level of the sperm count at onset and the type of shift, a dramatic decline from a high level in a multiplicative model indicating a marginal change and a minor decline from a low level in an additive model representing a strong decrease in fertility. In some cases sperm count, therefore, may be an early warning of changes in fertility.
Sperm concentration and total sperm counts from single semen and samples from each of 4435 patients requesting vasectomy between September 1972 and December 1977 were analyzed for circannual (about 1 year) rhythmicity. Although large temporal variations were found both between years and within years, a trend was noted for higher sperm concentration during the winter than during the summer. When the entire series of data were analyzed by months, a strong circannual pattern was apparent, with the highest sperm counts between February and March and the lowest counts during September. To the authors' knowledge, this is the first report of a circannual rhythm in human sperm concentration and total sperm count. The data must be considered preliminary, but if confirmed by other investigators studying comparable populations, the influence on clinical investigations will be profound.
In some countries, sperm counts in normal human semen seem to have declined over the last 50 years. If this decline is real and due to environmental factors, falls might also be seen in sperm numbers in the semen of farm animals. Sperm counts are available for bull, boar and ram from the early 1930s, obtained using techniques similar to those used for human semen. Data have been obtained from the literature between 1932 and 1995 from 137 studies involving bulls, 76 involving boars and 130 involving rams. All were normal adult animals, from which semen was collected regularly but at a frequency which would not be likely to cause a fall in sperm counts. The references were obtained systematically from Animal Breeding Abstracts, and where possible the original articles were consulted to obtain mean values for each study; where the original reference was not easily obtainable, values were taken from the abstract. The bull data showed no correlation of sperm count with year of publication (r2 = 0.000), for the boars there was a slight but non-significant positive correlation (r2 = 0.041), and for the sheep there was a slight, but significant, rise in sperm counts with time (r2 = 0.124 for sperm counts and 0.126 for total sperm per ejaculate; not all authors gave both values). It would appear that, if the fall in human sperm counts is real, then it must be due to something which is not affecting farm animals.
Two hundred eighty six human semen samples with sperm counts above 200 million/ml, were divided into 3 groups according to semen volume: (1) less than 1 ml (low), (2) 1 ml-5 ml (normal), and (3) greater than or equal to 6 ml (high). Each group was examined for routine andrological parameters. Also examined was a possible correlation between sperm counts, semen volumes, and ages of patients. The quality of motility (percent and grade) and viability of sperm were generally lowest in specimens with a volume below 1 ml and highest in those of normal volume. Proportions of morphological normality exhibited a similar trend, lacking, however, statistical significance. The mean fructose content of low-volume semen was significantly decreased in comparison with those of normal volume. Patients with low-volume semen and sperm counts above 200 million/ml were older than those with similar sperm counts and normal volume. The mean ages of all patients with high sperm counts of semen were higher than of those with lower sperm counts. It was assumed that in contradiction to specimens with high sperm counts and low volume, those whose volumes range from 1 ml-5 ml should be considered normal with respect to motility, viability, and morphological normality.
Methyl parathion (MP; o,o-dimethyl o-4-nitrophenyl phosphorothioate) is an organophosphorous pesticide used world wide to spray agricultural crops. The present study was aimed to investigate the genotoxic and cytotoxic effects on male germ cells and their possible relation with testicular ascorbic acid levels. Adult male Wistar rats (n=5/group) received MP at 0, 0.5, or 1 mg/kg (experiments 1 and 2) for 12 days and 0, 0.75 or 1.5 mg/kg (experiment 3) for 25 days (i.p.) everyday at intervals of 24 h. The epididymal sperm count, sperm abnormalities and testicular ascorbic acid levels (by 2,4-dinitrophenyl hydrazine method) were estimated on days 130, 77 and 17 following the last exposure in experiments 1, 2, and 3, respectively. Virgin untreated female rats were mated with treated males from experiments 2 and 3 for a week effective from day 35 to 41 after the first treatment, and fertility indices were measured after the birth of pups. Sperm count was decreased in experiments 2 and 3 (P<0.01), and in all three experiments, the abnormal sperms increased (P<0.001). Concomitantly, the ascorbic acid levels decreased in the testis (P<0.05-0.001; one-way ANOVA and Bonferroni's post hoc test). The body weights of offspring of treated males did not show significant changes from those of the controls, although there were some decreases observed. MP reduced the lactation index in experiment 2 (P<0.001; Chi-square test). The number of pups/parent along with fertility indices showed some numerical decrease but without any statistical significance. The present findings suggest that MP is a weak genotoxic and cytotoxic agent in the rat exposed to human exposure dose-levels, and that these effects, except the fertility are well correlated with decreased ascorbic acid level in the testis. Furthermore, MP-induced changes in the germ cells do not have any significant effects on F1 generation.
OBJECTIVES: There has been an enormous amount of interest as to whether sperm counts are declining over time. We sought to compare a contemporary group of fertile men to those from the MacLeod study of 1951 to ascertain whether sperm counts in fertile men have changed over time. METHODS: We obtained sperm count data from 374 fertile men who banked sperm in Minnesota prior to vasectomy from 1971 to 1994 and compared them to sperm count distributions from the 1000 fertile men of MacLeod's study. Semen analyses were performed as per World Health Organization guidelines using identical techniques in both the present and MacLeod studies. RESULTS: The contemporary group had a mean sperm count of 102 +/- 81 x 10(6)/mL (median 85 x 10(6)/mL) compared to 107 +/- 74 x 10(6)/mL (median 90 x 10(6)/mL) for MacLeod's data. There are no significant differences in mean or median sperm counts or sperm count distributions between the groups. CONCLUSIONS: We find remarkable similarities in sperm count distributions in cohorts of fertile men from 1951 and 1971 to 1994. Sperm counts in fertile men have not changed appreciably in the 40 years since MacLeod's report.
Several recent reports have suggested that the sperm counts of normal men are declining in most countries. In this study the sperm counts of Finnish men, and their possible changes during the past 28 years, were investigated. The material consisted of semen samples from 238 normal healthy men of unknown fertility and 5481 men from infertile couples. The means (medians) of semen volume, sperm density and total sperm count in normal men were 3.3 (3.0) ml, 133.9 (94.0) x 10(6)/ml and 396.6 (309.0) x 10(6), respectively. These parameters and the relative frequency distribution of the sperm density were similar to those reported elsewhere in the 1940s. Multiple linear regression analysis revealed a significant decrease in semen volume, whereas sperm density and total sperm count of infertile men had not changed significantly during the past 28 years. In addition, no change in sperm counts was associated with the year of men's birth.
A new chamber for sperm count and motility estimation is described. This chamber, which is only 10 micron deep, enables free horizontal movement of spermatozoa in one focal plane and provides conditions for the examination of undiluted samples. Therefore, with the aid of this instrument it is possible to compare sperm motility in various samples from the same person or in different samples at different times. This can be done either by simple estimation or with any other method of motility evaluation chosen by the examiner. The sperm count can be made rapidly and directly from an undiluted, preheated sample by counting spermatozoa in the area of a grid located within the eyepiece; the count is expressed in millions per milliliter. Thirty-seven specimens were analyzed with this chamber. Statistical evaluation of the results revealed high precision, accuracy, and reliability of sperm counts when compared with the hemocytometric method. Better results were obtained when motility estimation was compared with the ordinary slide technique. Easy performance, rapid sperm counts, and improvement of motility estimation make this chamber a useful tool where sperm analysis is carried out.
Semen analysis still remains an important diagnostic procedure in male infertility evaluation. For the purpose of standardization and uniformity in the interpretation of sperm count results, the accuracy of three different counting chambers (improved Neubauer (IMN), Makler, and Horwells) were evaluated. Semen samples produced by 50 men were analyzed with the three different counting chambers using World Health Organization guidelines. The overall precision values of sperm count were: IMN 9.7%, Makler 5.9%, and Horwells 7.1%. The mean sperm counts (+/- SEM) were 78.6 (+/- 10.1), 119.1 (+/- 14.1), and 211.5 (+/- 27.5) million spermatozoa/ml respectively. Statistically significant differences were revealed when the sperm count results obtained with the different counting chambers were compared, i.e., IMN vs Makler (P < 0.05), IMN vs Horwells (P < 0.001), and Makler vs Horwells (P < 0.01). The sperm count results obtained from the 50 samples were classified into four subgroups (A = 1-20, B = 21-50, C = 51-100, and D = > 100 million spermatozoa/ml) using IMN as a reference chamber. Errors reflected as progressively poor SEM of sperm count (A = 1.1, 3.2, 4.1; B = 3.0, 6.1, 12.4; C = 3.4, 17.0, 23.9; and D = 14.1, 21.3, 46.3) were observed for IMN, Makler, and Horwells counting chamber respectively in each group. This study revealed that inherent errors abound when different counting chambers are used for sperm count. While IMN gave the lowest sperm count, Horwells recorded the highest. Makler counting chamber gave midway values and conforms with recommendations in the literature about its accuracy.
PURPOSE: We determined if a statistical relationship exists between changes in sperm counts and birth rates by comparing data from a single geographic location for a 24-year period. MATERIALS AND METHODS: We retrospectively analyzed data from 660 men who banked 1,972 semen samples before vasectomy in Minnesota from 1971 to 1994. Using general linear models, annual variations in sperm count were determined after adjusting for age, duration of abstinence and seasonal (monthly) effects. Adjusted annual mean sperm count was then correlated with regional birth rate data obtained from The National Center for Health Statistics. RESULTS: Multiple regression analysis revealed a significant linear increase in mean annual sperm count at an estimated rate of 1.03 x 10(6) sperm per ml. per year (b = 0.14, t = 5.641, p < 0.0001). There was no effect of age (t = -0.814, p = 0.4156) but there were significant effects of abstinence (b = 0.14, t = 8.808, p < 0.0001) and month of sperm banking (b = 0.025, t = 5.00, p < 0.0001) on sperm counts. Using analysis of covariance there was a significant, nonlinear (year-to-year) fluctuation in mean sperm counts (F = 8.63, p < 0.001). For the study period mean birth rates in Minnesota (live births per 1,000 population) fluctuated yearly from 13.8 in 1973 to 16.7 in 1981. There was a strong correlation between adjusted mean yearly sperm count and annual birth rates (r = 0.63, p = 0.001). CONCLUSIONS: We found a statistically significant correlation between yearly variations in mean sperm counts and birth rates. Our data suggest that variations in male reproductive function may affect population based birth rates and, therefore, may be more important than previously understood.
Epididymal sperm counts, a common measurement in male reproductive toxicity studies, are routinely determined using a hemacytometer. Recently, computer assisted methods for automated sperm counts have been developed. In the present study we evaluated an automated system, the TOX IVOS (Hamilton Thorne Research, Beverly, MA) HTM-IDENT option, that utilizes a DNA-specific stain and fluorescence illumination to identify sperm for enumeration. Cauda and caput epididymal sperm counts were determined in 48 adult male Sprague-Dawley rats, using both the hemacytometer and HTM-IDENT. The mean hemacytometer and HTM-IDENT counts (+/- SD) were 250 +/- 43 and 254 +/- 52 million, respectively, for cauda sperm, and 123 +/- 13 and 127 +/- 18 million, respectively, for caput sperm. The average coefficient of variation using the hemacytometer was 13.8% as compared to 17.3% for the HTM-IDENT. Comparison of the machine count and a visual count from the Display Statics screen of the HTM-IDENT indicated that when two or more sperm heads touched or overlapped, the machine counted them as one. Manual (visual) and machine counts when compared over a range of nine concentrations from 3.7 to 47.8 million/mL differed by 4 to 12% at the lowest to highest concentration. The concentration of epididymal sperm samples used in comparing the two counting methods ranged from 5.8 to 17.7 million/mL. Therefore, the HTM-IDENT undercounting error attributable to sperm heads touching was less than 6%. Overall the data indicate good agreement between the HTM-IDENT and the hemacytometer counts. Furthermore, both counting time and technician fatigue were markedly reduced. Thus the HTM-IDENT option improves the efficiency of epididymal sperm counting without loss of precision.
In women, chronic and intense endurance exercise is frequently associated with menstrual cycle alterations. In men, the effects of similar amounts of exercise are less well-studied. We tested the hypothesis that endurance exercise in men is also associated with alterations in reproductive function. We studied 12 marathon runners and 12 age-matched, lean controls; serum and semen samples were collected every 2 weeks for 12 weeks. Sperm counts, sperm morphologies, and mean levels of testosterone (T), free T, sex hormone binding globulin, cortisol, follicle-stimulating hormone, and biologically active luteinizing hormone (LH) were similar in the two groups. Mean levels of immunologically active LH were somewhat higher in the marathoners. We conclude that this level of strenuous, long-term endurance exercise does not have major adverse effects on reproductive function in men.
Eighty-six couples with long-standing infertility and poor postcoital test, due to oligozoospermia and/or asthenozoospermia (68 cases) or mucus hostility (18 cases), were treated by 411 intrauterine inseminations (IUI) with motile sperm suspensions from the husband's semen. The pregnancy rate per couple in the group with abnormal semen was lower than in the group with mucus hostility (22% versus 38.9%). Influence of seminal and other parameters on outcome of IUI was assessed by discriminant analysis, and a significant correlation with pregnancy rate was found for motile sperm count and sperm morphology. Teratozoospermia (normal morphology less than 50%) affected the outcome of IUI both when associated with moderate oligozoospermia and/or asthenozoospermia (motile sperm count greater than or equal to 5 X 10(6)/mL) (success rate per couple: 11.1%), and, even more, when associated with severe oligozoospermia and/or asthenozoospermia (motile sperm count less than 5 X 10(6)/mL), where no pregnancy was achieved. In the absence of teratozoospermia, the success rate per couple both in severe and in moderate oligozoospermia and/or asthenozoospermia had similar results (33.3% versus 35.7%). In conclusion, the absence of teratozoospermia appears to be an effective criterion for selecting couples with infertility due to oligozoospermia and/or asthenozoospermia who may benefit from IUI.
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