Correlation between in vitro fertilization and human sperm density and motility

Group-training of rams at puberty for artificial vagina-mediated semen collection and its influence on semen quality and sexual behavior

There is a paucity of information with respect to group-training for artificial vagina and its influence on semen characteristics and sexual behavior of young untrained rams. A total of 18 healthy Najdi rams (with an initial body weight of 40-45 Kg and 7-8 month-old) were consequently used herein to test the usefulness of group-training for artificial vagina-mediated semen collection during the breeding season. Rams were randomly segregated into three groups (n = 6 rams per protocol), and the whole experiment was lasted for 10 weeks. The 1^st group was subjected to a training protocol where one untrained ram was placed for 20 min with a teaser ewe, while the 2^nd group were subjected to a protocol where one untrained ram was placed for 20 min with one trained ram and a teaser ewe, whereas the 3^rd group were subjected to a protocol where three untrained rams were placed for 20 min with one trained ram and a teaser ewe. The obtained results clearly (P < 0.05) showed that training young rams in group has increased their sperm concentration and sexual stimulation, shortened the period of their training time, and descriptively had a complete training efficiency. The sexual stimulation of young untrained rams was intensified by the competition between rams in the co-presence of a trained ram. Collectively, these data may suggest that group-training of rams at puberty is a better protocol for AV-mediated semen collection compared to individual training. Some shortcomings were noted herein, but research dealing with this subject may very well improve the reproductive performance of young untrained rams.

In vitro and in vivo fertilization potential of cryopreserved spermatozoa from bull epididymides stored for up to 30 hours at ambient temperature (18 °C-20 °C)

The aims of this study were to compare the viability and in vivo and in vitro fertilization potential post-thaw sperm collected at different times postorchiectomy from bull epididymides (EP) at 18 °C to 20 °C, with those of semen collected by electroejaculation (EJ) from the same bulls. Semen samples were collected by EJ from 10 Zebu bulls and cryopreserved. A week later 20 epididymides from these bulls were obtained by orchiectomy and randomly divided into five groups (G) to be maintained at ambient temperature for 6, 12, 18, 24, and 30 hours before sperm recovery by retrograde flow. The sperm were cryopreserved, and post-thaw parameters were determined by both computer-assisted sperm analysis and morphologic analysis. In vitro fertilization of oocytes was performed to assess the cleavage rate, blastocyst rate, total number of cells, and hatching rate of embryos. The G30 sperm samples were also used for fixed time artificial insemination (FTAI) of Zebu heifers (n = 10). The results of post-thaw sperm viability showed that total and progressive motility and plasma membrane integrity were lower in sperm in which cryopreservation was delayed for 30 hours, showing a negative correlation of these parameters with delay before cryopreservation. In all groups, it was possible to obtain viable embryos, and embryos from G6 samples had more cells than the other groups. The greatest embryo production rates were observed in G6, G12 and G18 (27.2 to 32.2%) and it was significantly lower in G24 and G30 samples. For EJ, many individual variations were observed in embryo production potential between bulls. G30 samples, with only 5.2% of post-thaw progressive motility, were able to fertilize and produced a pregnancy. To the authors' knowledge, this is the first time in vitro embryos up to 8 days of development and a pregnancy after FTAI have been produced with sperm from bull epididymides that had been stored at 18 °C to 20 °C for up to 30 hours.

WITHDRAWN: Effects of various glycerol concentrations and thawing temperatures on CASA parameters and acrosomal integrity of frozen-thawed canine spermatozoa

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The impact of epididymal and accessory sex gland function on sperm motility

BACKGROUND

Little is known about the regulation of sperm motility, which is an important predictor of male fertility. However, both testicular and post-testicular factors may be involved, although the impact of the latter has been relatively poorly investigated.

METHODS

In semen samples from 301 young men from the general Swedish population (mean +/- SD age 18.2 +/- 0.4 years), we assessed sperm motility by use of a manual method as well as computer-assisted sperm analysis (CASA) and correlated these values to seminal levels of neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc and fructose.

RESULTS

There were significant positive correlations between seminal levels of NAG, and PSA and CASA percentage motile sperm (r = 0.158, P = 0.009; r = 0.155, P = 0.01 respectively), and significant negative correlations with CASA percentage immotile sperm (r = -0.206, P = 0.001; r = -0.157, P = 0.009 respectively). In a multiple regression analysis it was found that, apart from sperm concentration, the level of PSA was the most significant and independent parameter in predicting percentage motile sperm (beta = 0.220, P = 0.037).

CONCLUSION

Our study demonstrated the regulatory effect of post-testicular glands on the motility of sperm. This is to our knowledge the first study showing a direct correlation between the seminal PSA levels and sperm motility in a group of men representing the general population. In future investigations and searches for specific treatment modalities in male infertility, more attention should be paid to the epididymis and accessory sex gland function.

Computer assisted semen analyzers in andrology research and veterinary practice

The evaluation of sperm cell motility and morphology is an essential parameter in the examination of sperm quality and in the establishment of correlations between sperm quality and fertility. Computer-assisted sperm analysis (CASA) allows an objective assessment of different cell characteristics: motion, velocity, and morphology. The development and problems related to this technology are raised in this review, paying particular attention to the biases and standardization requirements absolutely needed to obtain useful results. Although some interesting results, mainly in humans, have already been obtained, many questions remain, which have to be answered to allow for further development of this technology in veterinary medicine, clinical fertility settings, physiological, and toxicology research activities. The main problem is related to the standardization and optimization of the equipment and procedures. The different CASA instruments have all demonstrated high levels of precision and reliability using different sperm classification methodology. Their availability gives us a great tool to objectively compare sperm motility and morphology and to improve our knowledge and ability to manipulate spermatozoa.

Evaluation of the percentage of sperm motility at 24 h and sperm survival ratio for prediction of in vitro fertilization

The present study was carried out to investigate the predictive value of the percentage of sperm motility after 24-h incubation and sperm survival ratio from semen and inseminated sperm suspension using grading of motility by WHO criteria with respect to the fertilization of oocytes in vitro. A total of 789 oocytes from 85 cases were inseminated and the mean fertilization rate obtained was 72.5%. There was no significant correlation between all of the sperm motility results with fertilization rate in vitro. All sperm motility results were not significantly different between the non-fertilizing group and the fertilizing group and also between the group of fertilization rate < or = 25th percentile (fertilization rate < or = 62.5%) and the group of fertilization rate > 62.5%. However, the initial percentage of rapid progressive sperm motility and progressive motility in semen and inseminated sperm suspension at 24 h gave significant differences between the group of fertilization < or = 50th percentile (fertilization rate < or = 80%) and the group of fertilization rate > 80%. Overall accuracy using these parameters for prediction of fertilization rate > 80% was only about 60%. In conclusion, the percentage of sperm motility at 24 h and sperm survival ratio in both semen and inseminated sperm suspension have no practical value in predicting fertilization rate in vitro. Moreover, detailed motility grading cannot improve the predictivity of these sperm motility parameters.

The routine assessment of sperm motility at room temperature and 37 degrees C

The World Health Organization (WHO) laboratory manual (1992) states that assessment of sperm motility can be performed at either 37 degrees C or room temperature (20-24 degrees C). The motility of spermatozoa in 44 semen samples (22 fresh samples and 22 frozen-thawed samples) was assessed at both of these temperatures and a significant difference in the motility profiles was noted, specifically an increase at 37 degrees C in the percentage (expressed here as median and ranges) of spermatozoa with excellent progressive motility and an overall increase in the percentage with total progressive motility. With fresh samples the excellent progressive motility increased from 41 (19-53) to 54 (30-66) and the overall motility from 58.5 (39-74) to 65.0 (40-79). With the frozen-thawed samples the excellent motility increased from 14 (1-33) to 25 (6-45) and the overall motility from 30.5 (14-51) to 33.0 (16-52). As the WHO laboratory manual was published 'In response to a growing need for the standardisation of procedures for the examination of human spermatozoa' it is proposed that only one temperature for routine analysis should be used, namely 37 degrees C, which may have more physiological relevance and eliminate effects of fluctuations in ambient laboratory temperature.

Predictive power of sperm motion analysis in in vitro fertilization

The correlation between sperm motion characteristics and in vitro fertilization was studied in 160 cycles, divided in two groups: those with male subfertility (N=42) and those with tubal disease (N=118). The group with male subfertility showed inferior performance, as indicated by a lower fertilization rate per oocyte (40% versus 66%) and per pick-up cycle (67% versus 93%). These two groups exhibited no significant difference in the mean sperm velocity, linearity, amplitude of lateral head displacement, and beat cross frequency in the pre swim-up and post swim-up specimens. The two groups differed in pre and post swim-up sperm motility, pre and post swim-up concentration, pre swim-up cumulative velocity at 110 to 140 Amicrom/sec and post swim-up cumulative velocity at 130 microm/sec. Logistic regression analysis was used to determine those variables that would predict fertilization; pre swim-up count and post swim-up motility proved to be the significant determinants. The results indicate that assessment of motion by automated semen analyzers does not supplement conventional semen analysis in the ability to predict fertilization.

Plasminogen activator activity and fertilizing ability of human spermatozoa

Mature spermatozoa contain a number of proteases that are supposed to contribute to their fertilizing ability. The present study was directed at plasminogen activator (PA), a protease that belongs to the group of serine proteases and converts the zymogen plasminogen to the active broad-spectrum protease plasmin. To investigate the possible role of PA in the fertilization process, we have measured sperm-bound PA activity in 63 patients included in an in-vitro fertilization (IVF) programme and assessed their relationship to standard semen parameters and the rate of fertilization. PA activity was correlated significantly with the sperm count, as well as with sperm motility and morphology. Using logistic regression analysis, specific PA (pmol pNA 10(-6) cells min-2) was found to significantly influence the probability of fertilization. Other significantly predictive factors were motility and the percentage of spermatozoa with normal morphology. The sperm concentration (10(6) cells ml-1) did not significantly affect the outcome of IVF. We suggest that sperm-bound PA is involved in the fertilization process and may represent a potential indicator of sperm fertilizing capacity.

Subnormal sperm parameters in conventional semen analysis are associated with discrepancies between fertilization and pregnancy rates in in-vitro fertilization and embryo transfer

Three hundred and twenty-eight consecutive treatment cycles in 168 couples were analysed retrospectively in order to examine the influence of conventional semen analysis results on the outcome of in-vitro fertilization and embryo transfer with respect to the occurrence of both fertilizations and pregnancies. All treatments were performed under maximally standardized and controlled conditions. Each of the three main determinants of the spermiogram, namely the concentration, motility and morphology of sperm in seminal plasma, was of significant importance for fertilization and subsequent pregnancy. Best correlations were achieved by counting the number of progressively (a+b) motile sperm and the number of normally formed sperm in seminal plasma. The pregnancy rate was reduced significantly in cases in which the sperm concentration was < 10 x 10(6) ml-1 (P < 0.01), or in which there was < 40% progressively motile sperm (P < 0.001), or < 30% normally formed sperm (P < 0.001). If more than one parameter in the spermiogram was abnormal, the fertilization rate depended mainly on the most disturbed sperm parameter. The implantation rate as well as the pregnancy rate was reduced significantly in patients with low progressive sperm motility and normal morphology rates. The difference could only be attributed partially to the lower number of embryos replaced. In conclusion, subnormal sperm quality seems to interfere with developmental stages beyond the process of fertilization.

The relationship between sperm ultrastructural features and fertilizing capacity in vitro

OBJECTIVE

To evaluate the relationship between ultramorphological features of the human sperm and its fertilizing capacity in vitro.

DESIGN

The study was performed retrospectively. Ultrastructural features were assessed using scanning and transmission electron microscopes in sperm samples of individuals who underwent an in vitro fertilization (IVF) treatment cycle no more than 6 months before the study.

SETTING

Institutional clinical care.

PATIENTS

Fifty-six infertile couples in whom mechanical infertility was diagnosed in the female partner. Patients were categorized as fertilizing when fertilization of at least 30% of the oocytes occurred (n = 27) and nonfertilizing when none of the oocytes fertilized in at least two consecutive IVF treatment cycles (n = 29).

RESULTS

The two groups differed significantly only in ultramorphological parameters of the sperm head and acrosome (head, F(8,36) = 2.8, P less than 0.02; acrosome, F(4,40) = 2.8, P less than 0.04), and especially in the following malformation patterns: hyperelongated head, acrosome deficiency, and acrosome damage. The suggested score based on these findings was able to predict 90% and 76% of the cases with and without fertilizing potential, respectively.

CONCLUSION

The ultrastructural morphology of the sperm head components is a key parameter for assessing the sperm fertilizing capacity in vitro.

Glass-bead column separation of motile and nonmotile human spermatozoa

Glass-bead columns were tested for their efficiency in concentrating motile human spermatozoa from frozen semen samples. The data show that glass-bead filtration concentrates the motile gametes in each sample and is significantly more efficient than the swim-up method for obtaining populations of motile spermatozoa. The data suggest that this method can be applied clinically to obtain motile spermatozoa from poor-quality semen for use in in vitro fertilization.

Sperm count and motility influence the results of human fertilization in vitro

In order to select sperm characteristics that can predict the outcome of in-vitro fertilization-embryo transfer (IVF-ET), semen samples delivered in conjunction with this treatment were studied carefully. We have analysed these data retrospectively in relation to the outcome of treatment. Ninety-one couples were treated for tubal infertility by IVF-ET. Fifteen women became pregnant. Sperm were isolated from semen using a swim-up technique and in most cases 40-80 x 10(3) (range 20-120 x 10(3)) motile sperm per ovum were used for insemination. The couples were divided into three groups: group A who achieved pregnancies, group B who achieved cleaved ova but no pregnancies, and group C who achieved no ova that were cleaved 48 h after oocyte recovery. Comparisons between these groups showed that some characteristics of the native semen samples and the swim-up preparations were significantly different: the sperm concentration (P = 0.001) and total sperm count (P = 0.003) in the native sample, the number of sperm recovered during 30 min of swim-up (P = 0.001), and the specific progressive motility of sperm in the swim-up preparation, both at the time of insemination and on each day, up to 5 days thereafter (P = 0.002-0.028). No pregnancy was achieved with a sperm concentration below 26 x 10(6) ml-1 in the native sample. Some of the sperm characteristics studied in this paper may be of value in the pretreatment evaluation for IVF treatment.

The relationship between sperm parameters and fertilizing capacity in vitro: a predictive role for swim-up migration

The relationship between sperm parameters and fertilizing capacity in vitro was examined retrospectively, with the aim of finding predictive criteria for successful in vitro fertilization. Three hundred thirty semen samples were used to inseminate 1462 oocytes. Conventional parameters of sperm concentration and percentage motility in the ejaculate as well as swim-up migration were analyzed in relation to fertilization rate. It was shown that the probability of fertilizing human oocytes in vitro decreases significantly when (a) the sperm concentration is below 20 x 10(6) spermatozoa/ml ejaculate (P = 0.006), (b) motility is lower than 80% (P = 0.002), or (c) less than 4 x 10(6) motile spermatozoa/ml are concentrated in the swim-up fraction (P less than 0.0001). It was also demonstrated that nonfertilizing sperm could not be distinguished from fertilizing sperm by the conventional criteria but rather by the average concentration of motile spermatozoa in the swim-up fraction [12.5 +/- 1.5 and 22.3 +/- 2.3 x 10(6)/ml for the 0 and the 100% fertilization groups, respectively (mean +/- SE; P less than 0.01)]. Thus, the swim-up migration technique can serve as a predictive test for the in vitro fertilizing capacity of sperm.

Does computerized image analysis of sperm movement enhance the predictive value of semen analysis for in-vitro fertilization results?

The influence of semen quality on fertilization rates in an in-vitro fertilization (IVF) programme was studied by analysing both conventional semen parameters and computerized movement characteristics. The study was based on 407 inseminated oocytes which were obtained from 50 patients in 113 laparoscopies. Sperm concentration did not correlate strongly with the fertilization rate. Sperm motility and morphology were the most meaningful parameters in predicting fertilization success. A drop in fertilization rate was found when sperm motility or normal morphology were below 40%. Sperm velocity measured in semen was the only sperm movement parameter which correlated with the fertilization rate, albeit weakly. The latter was reduced when average sperm velocity in semen was less than 50 microns/sec. Conventional semen parameters seem to be more predictive of the fertilizing potential of an ejaculate than movement characteristics obtained by computerized image analysis.

Predictive value of sperm morphology and movement characteristics in the outcome of in vitro fertilization of human oocytes

One hundred fourteen semen samples from Chinese males were analyzed for routine semen parameters including the semen volume, sperm count, percentage motility, and percentage normal morphology. Of these 114 samples, 54 also had movement characteristics of seminal and swim-up sperm evaluated by the computer image analyzer system (Cellsoft; Cryo Resources Co., New York). All semen samples were subjected to the swim-up procedure to harvest the motile sperm before inseminations of human oocytes. Fertilization was considered to have occurred when at least one oocyte was observed with two or more pronuclei. Semen samples were classified as infertile (0% fertilization rate; N = 32) or fertile (greater than 0% fertilization rate; N = 82) before statistical analyses. There was a significant difference (P less than 0.005) in percentage normal morphology of seminal sperm between the fertile (mean +/- SE; 67.3 +/- 1.2%) and the infertile (59.3 +/- 2.2%) samples. The percentage normal morphology of seminal sperm correlated (r = 0.3049; P less than 0.002) with the fertilization rate and this parameter was selected by the multivariate stepwise discriminant analysis as the discriminator capable of predicting the fertilization rate with 57.9% accuracy. Statistical analyses of samples where sperm movement was also evaluated demonstrated that there was significant differences (P less than 0.01) between the fertile (N = 38) and the infertile (N = 16) samples in percentage normal morphology of seminal sperm (67.8 +/- 1.8% vs 56.2 +/- 2.6%) and curvilinear velocity of swim-up sperm (89.2 +/- 3.5 vs 68.2 +/- 7.2 microns/sec).(ABSTRACT TRUNCATED AT 250 WORDS)

Improved sperm concentration, motility, and fertilization rates following Ficoll treatment of sperm in a human in vitro fertilization program

Duplicate sperm samples from the spouses of 54 patients admitted to an in vitro fertilization program were prepared by the swim-up and a simplified procedure using Ficoll. Cellsoft (CRYO Resources, New York, NY) sperm curvilinear velocities (microns/sec) and mean amplitude of lateral head displacement values (microns) equivalent to grade 1 and 2 visual sperm motility were significantly higher for Ficoll as compared with swim-up samples (P less than 0.01). Fertilization rates were significantly higher in the Ficoll as compared with the swim-up group for poor semen samples (grade less than 2: 58% versus 24%; P less than 0.01) and normal semen samples (grade greater than or equal to 2: 85% versus 78%; P less than 0.05). Ficoll sperm separation appears to be an excellent method of yielding increased fertilization rates in in vitro fertilization programs.

Relationship between the results of sperm analysis and GIFT

In vitro fertilization (IVF) and GIFT have been proposed as therapeutic approaches in infertile couples where a significant male factor is present. To date, few published data are available relating the success rate of GIFT to the severity of the male factor. In this report the results of the first 172 GIFT cases were analyzed. The overall pregnancy rate was 18.0%. The relationship between the occurrence of pregnancy and sperm count (millions/ml), total sperm count (millions/ejaculate), % motility, motile sperm count (millions/ml) and total motile sperm count (millions/ejaculate) were examined. Significant direct correlations were observed between the clinical pregnancy rate and sperm count, total sperm count, motile sperm count and total motile sperm count. Motile sperm count and total motile sperm count had the best correlations with clinical pregnancy rates, which were over 24.0% in groups with motile sperm counts exceeding 40 X 10(6) cells/ml or total motile sperm counts greater than 100 X 10(6)/ejaculate. The clinical pregnancy rates were 12.5% and 7.7%, respectively, for groups with motile sperm counts under 10 X 10(6)/ml and total motile sperm counts below 25 X 10(6)/ejaculate. No correlation was found between percent motile cells and pregnancy rate. Results of the sperm penetration assay using zona-free hamster eggs were available in a subpopulation of 27 patients. No significant correlation between this sperm penetration assay and pregnancy rate could be demonstrated. The incidence of chemical pregnancy showed a significant negative correlation with the total motile sperm count, indicating a higher incidence of early pregnancy wastage in cases of oligozoospermia.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of sperm motility on human in vitro fertilization

Several sperm motility parameters in semen prepared by the swim-up technique were compared with IVF rates in 84 patients. The patients were either on clomiphene + human menopausal gonadotrophin or follicle stimulating hormone + human menopausal gonadotrophin stimulation regimens. Motility ratings were assessed both manually according to World Health Organization guidelines as well as computer-automated semen analysis (Cellsoft, Cryoresources, USA). Motility ratings of greater than or equal to 2 yielded significantly higher fertilization rates (78-82%) than ratings below 2 (20-23%) (p less than 0.001) for patients on both regimens. Velocity (41, 55, 78 microns/sec) and mean amplitude of lateral head displacement (1.96, 3.29, 4.91 microns) correlated significantly with and between manual ratings of 1, 2, and 3, respectively (r = 0.83; p less than 0.01). No significant differences were observed in linearity and beat/cross frequency between the manual ratings, although beat/cross frequencies tended to reduce linearly with increases in intensity of motility. The velocity of sperm motility has a significant effect on fertilization rates, and cut-off points of greater than or equal to 2 or greater than or equal to 50 microns/sec predict the actual potential and likely success of in vitro fertilization. These criteria on the swim-up semen should be used in the selection of patients admitted to IVF programs, and they justify the necessity of research investigations to improve motility in those patients with sluggish motility.

Accuracy of sperm characteristics in predicting the in vitro fertilizing capacity of semen

Based on the results of in vitro fertilization (IVF) in 56 couples, the power was assessed of traditional sperm characteristics of native semen to discriminate between in vitro fertile and in vitro infertile semen. The number per ejaculate of spermatozoa with regular oval heads was the best discriminant, followed by the concentration of progressively motile spermatozoa. This contrasts with the in vivo fertilizing capacity, which depends mostly on the proportion and concentration of spermatozoa with rapid linear progression. The lower limit of sperm characteristics was assessed as the fifth percentile of in vitro fertile semen and was compared with the lower limit of semen of fertile men and of subfertile men who achieved spontaneous or treatment-related conception in vivo. It appeared that the semen quality needed for in vitro fertilization is inferior to that of fertile men but not remarkably different from that of subfertile men who achieved spontaneous conception during 1-year follow-up after consultation. If conventional methods for semen preparation are used, there seems to be no major advantage in favor of IVF for the treatment of male infertility due to sperm deficiency. An increased success rate may, however, be attained, thanks to improved techniques of semen collection, semen preparation, and oocyte insemination.

Semen characteristics of 49 fertile males

We examined the semen characteristics of 49 men whose partners had conceived within the last 16 weeks. There was considerable variation in the semen results. The % of morphologically ideal forms and the absence of sperm bound antibodies appeared to be the two most important semen characteristics when assessing the fertilising potential of the samples. A large proportion of samples (70%) when compared to the WHO standards of normality, were classed abnormal, however, only 25% of the samples had greater than 2 abnormal characteristics. It is diagnostically more relevant to determine the number of abnormalities within a sample rather than categorising the sample as "normal" or "abnormal".