Sperm morphology assessment: diagnostic potential and comparative analysis of strict or WHO criteria in a fertile and a subfertile population

Predictive Value of Teratospermia During Initial Sperm Analysis on the Success of Intrauterine Insemination Cycles

OBJECTIVE

To evaluate the predictive value of sperm morphology, specifically teratospermia, seen during initial semen analysis on the success of intrauterine insemination (IUI) cycles and pregnancy outcomes.

METHODS

A retrospective cohort analysis on patients undergoing IUI at a large US fertility network. Baseline demographic characteristics, primary infertility diagnoses, and pregnancy outcomes were recorded. A total of 27,925 IUI cycles in 16,169 unique patients were analyzed. IUI cycles were grouped by a sperm morphology of 1% (n = 3799), 2% (n = 5506), 3% (n = 4857), or 4% or greater (n = 13,763). The outcome measures were pregnancy rate (positive pregnancy test), clinical pregnancy rate (CPR) (ultrasound confirmation of a gestational sac with a yolk sac around 5-6 weeks), live birth rate, and miscarriage rate.

RESULTS

Sperm morphology is a significant predictor of pregnancy rate (P = <.001), CPR (P =.011), and live birth rate (P = .026) following IUI. In each of these outcome measures, patients with 1% normal forms had the lowest percentage of success, and patients with 4% or greater normal forms had the most success. Relative outcome percentages, however, were similar in each group. Live birth rates in the 1%, 2%, 3%, and >4% group were 12.3%, 13.1%, 12.7%, and 13.9%, respectively. Sperm morphology is not a significant predictor of miscarriage rate per clinical pregnancy post-IUI (P = .054).

CONCLUSION

Sperm morphology was a statistically significant predictor of pregnancy, clinical pregnancy, and live birth but not miscarriage rate after an IUI cycle. Higher morphology percentages were associated with increasingly favorable outcomes. However, the small observed differences did not demonstrate clinical significance.

Spatiotemporal trends in human semen quality

Over the past four decades, studies of various designs have reported spatial and temporal trends in human semen quality. Several standardized-methodology studies in homogeneous populations that compare specific cities within a country or a continent provide clear evidence of geographical differences in sperm production, even over short distances within the same country. Human sperm production is widely believed to be declining over time, but evidence from the scientific literature is less clear. Studies based on repeated cross-sectional data from a single centre have shown mixed results. Among the numerous retrospective studies conducted in a single centre, only some included homogeneous groups of men and appropriate methods, and most of them suggest a temporal decrease in human sperm production in the geographical areas considered. Conclusions reporting temporal trends in sperm production that came from existing retrospective multicentre studies based on individual semen data and those using means, medians or estimates of sperm production are questionable, owing to intrinsic limitations in the studies performed. Regardless of study design, studies on the percentage of motile or morphologically normal spermatozoa are still limited by the inherent variability in assessment. Overall, available data do not enable us to conclude that human semen quality is deteriorating worldwide or in the Western world, but that a trend is observed in some specific areas. To understand these trends and contrasts in sperm and semen quality, prospective studies should be encouraged and combined with assessment of the male exposome.

Several studies over the past few decades have suggested that sperm quality varies by geographical region and might be subject to a temporal decline worldwide. However, the data supporting these conclusions have come from studies of various methodologies and heterogeneous populations, making them unreliable. In this in-depth Review, Chevrier and colleagues discuss the data surrounding discussion of spatiotemporal trends in semen parameters and consider how these trends and the factors promoting them interact.

The vast literature on human semen quality trends is extremely heterogeneous in terms of the populations studied and study designs, and so these studies have been unable to draw firm conclusions.

Understanding the data around spatiotemporal semen trends requires a focus on the methodological choices and application of criteria to filter findings from the studies with optimal design.

Numerous appropriately designed studies suggest unambiguous geographical contrasts in human sperm production; however, evidence of a decline in sperm production is reliable only in specific populations and cities in which studies with a complete set of quality criteria have been conducted.

By contrast, suggestions of a worldwide drop in human semen quality on the basis of retrospective multicentre studies cannot be substantiated, owing to intrinsic limitations in the studies performed.

Many and varied factors of variation, in particular the diverse modalities of assessment, do not enable us to conclude that clear temporal trends of sperm motility and normal morphology are present.

Progress in our understanding of the highlighted trends and their causal factors requires prospective studies that minimize all known biases combined with the assessment of men’s exposome.

Association between a marker of sperm DNA damage and sperm indices in infertile males in Benin City, Nigeria: A cross-sectional study

Background

Studies have shown oxidative DNA damage is associated with male infertility.

Objective

This study determines the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and some markers of oxidative stress in seminal fluid of males investigated for infertility and men of proven fertility in Benin City, Nigeria.

Materials and Methods

Semen samples produced by self or assisted masturbation were analyzed by microscopic technique according to the World Health Organization guidelines. Thereafter, samples were centrifuged and seminal fluid plasma separated and stored at -20°C prior to assay for 8-OHdG and oxidative stress biomarkers. Based on the sperm concentration/count, the overall samples were grouped into the following categories: normospermia (n = 20), oligozoospermia (n = 30), and azoospermia (n = 20). The control group comprised of 30 age-matched males of proven fertility. The seminal fluid 8-OHdG, total antioxidant status, superoxide dismutase and malondialdehyde (MDA) were assayed through ELISA and spectrophotometric methods, respectively.

Results

Seminal plasma level of 8-OHdG and MDA were significantly higher (p = 0.01) in infertile subjects than controls. The mean levels of 8-OHdG and MDA in infertile subjects were higher in azoospermia than oligospermia than normospermia and so, was least in the normospermia. Conversely, the mean levels of total antioxidant status and superoxide dismutase were significantly lower (p = 0.01) in infertile than fertile the control male subjects with levels higher in normospermia than oligospermia and least in azoospermia. Moreover, the seminal 8-OHdG correlated negatively with sperm count (r = -0.359, p = 0.01), percent motility (r = -0.388, p = 0.04), and percent morphology (r = -0.327, p = 0.02).

Conclusion

The assessment of sperm DNA damage in addition to routine seminal fluid analysis may play an important role in specific diagnosis and management of male infertility.

Proteomic Analysis Reveals that Topoisomerase 2A is Associated with Defective Sperm Head Morphology

Male infertility is widespread and estimated to affect 1 in 20 men. Although in some cases the etiology of the condition is well understood, for at least 50% of men, the underlying cause is yet to be classified. Male infertility, or subfertility, is often diagnosed by looking at total sperm produced, motility of the cells and overall morphology. Although counting spermatozoa and their associated motility is routine, morphology assessment is highly subjective, mainly because of the procedure being based on microscopic examination. A failure to diagnose male-infertility or sub-fertility has led to a situation where assisted conception is often used unnecessarily. As such, biomarkers of male infertility are needed to help establish a more consistent diagnosis. In the present study, we compared nuclear extracts from both high- and low-quality spermatozoa by LC-MS/MS based proteomic analysis. Our data shows that nuclear retention of specific proteins is a common facet among low-quality sperm cells. We demonstrate that the presence of Topoisomerase 2A in the sperm head is highly correlated to poor head morphology. Topoisomerase 2A is therefore a potential new biomarker for confirming male infertility in clinical practice.

Do pregnancy rates differ with intra-uterine insemination when different combinations of semen analysis parameters are abnormal?

OBJECTIVE

To evaluate the relationship of one or a combination of semen analysis parameter results on insemination outcomes.

MATERIAL AND METHODS

A retrospective analysis was performed to evaluate the effect on pregnancy rates in relation to one or more abnormal semen analysis parameters based on the 2010 World Health Organization semen analysis guidelines.

RESULTS

Nine hundred eighty-one couples underwent 2231 intrauterine insemination cycles at the Stanford Fertility and Reproductive Medicine Center. In our study, the pregnancy rates ranged from 11-25% when an individual or combined semen analysis parameters were analyzed. Similar pregnancy rates were found when one, two, and in most cases three parameters were abnormal. When a single parameter was abnormal among volume, concentration, and motility, pregnancy rates were mainly unaffected. There was the exception of total sperm count where pregnancy rates were diminished when counts were below 39 million (p=0.04).

CONCLUSIONS

Clearly, total sperm in the specimen and not the concentration of sperm per milliliter was the critical factor for predicting pregnancy. Therefore, a reorganization of semen analysis reports should be done emphasizing the total amount of sperm present and de-emphasizing concentration of sperm.

Deficiency in Outer Dense Fiber 1 Is a Marker and Potential Driver of Idiopathic Male Infertility

Globally, ∼1 in 15 men of reproductive age are infertile, yet the precise mechanisms underlying their gamete failure are unknown. Although a semen analysis is performed to determine fertilizing potential, the diagnostic suitability of this analysis has been questioned in several reports, as many men, classified as infertile according to their semen analysis, subsequently turn out to be fertile. Herein, we have used a quantitative (phospho)-proteomic analysis, using enrichment on titanium dioxide followed by ion-trap mass spectrometry (LC-MS/MS), to compare the semen of infertile versus fertile males. One protein, namely outer dense fiber 1 (ODF1), was dramatically reduced in infertile males. Using specific antibodies, we then screened the gametes of a cohort of suspected infertile men and demonstrated a reduction in the amount of ODF1 compared with fertile controls. Stress treatment of sperm deficient in ODF1 caused the head to decapitate, suggesting why these gametes fail to initiate fertilization. Interestingly, electron micrographs of ODF1-deficient spermatozoa revealed an abnormal connecting piece, indicating several developmental defects with both the implantation plate and the thin laminated fibers. In some cases, the implantation plate appeared to be reduced in size or was overburdened by granular material near the connecting piece. Hence, a strong reduction ODF1 is a marker of idiopathic male infertility and a potential driver of this condition.

Analysis of the correlation between sperm DNA integrity and conventional semen parameters in infertile men

OBJECTIVE

A male factor is responsible in approximately 30-40% of couples receiving infertility treatment. Routinely, such couples undergo semen analysis including parameters such as sperm count, motility and morphology. Generally, the analysis of sperm DNA damage, shown to have a significant clinical importance by many studies, is recognized as an advanced test that is not included in routine infertility tests. Intracytoplasmic sperm injection method, commonly employed in the current infertility treatment protocols, lowers the fertilization rate, however, fertilization can occur even with a damaged DNA which is known to pose a risk in the subsequent pregnancy period. The relation between sperm morphology and the degree of sperm DNA damage has not yet been understood clearly. In this study, we aimed to investigate the association between routine semen analysis and sperm DNA integrity assay, another advanced but costly method.

MATERIAL AND METHODS

The degree of DNA damage was compared with the results of semen analysis, based on the WHO criteria, in 399 male patients who received comet assay for sperm DNA integrity. The statistical correlation analyses were performed with Windows SPPS statistical package program.

RESULTS

Accordingly, the sperm DNA damage was found to be correlated with all 3 parameters (sperm count, forward motility, and morphology) examined by the semen analysis (p<0.001). Total sperm DNA Damage Count was 226, 216, and 210 arbitrary units in patients with a sperm count <15 mil/mL, forward moving motility <32%, and normal morphology <4%, respectively. The difference with the normal individuals was statistically significant (p<0.001).

CONCLUSION

In light of the comet assay results, higher degree of sperm DNA damage is associated with significant impairment of all seminal parameters.

Can intra cytoplasmatic morphologically selected sperm injection (IMSI) technique improve outcome in patients with repeated IVF-ICSI failure? a comparative study

OBJECTIVE

Spermatozoal morphology was reported to effect fertilization, embryo quality and pregnancy results in spontaneous conception and ART. Intracytoplasmic morphologically selected sperm injection (IMSI) is an innovative, not invasive technique, which examines the sperm with no harm at a magnification of 6000 × in order to obtain optimal sperm to perform IVF-ICSI. We evaluated the efficiency of IMSI technique in patients with repeated IVF-ICSI failure of at least three cycles with no viable pregnancy and/or very poor sperm quality.

STUDY DESIGN AND METHODS

All couples who performed IMSI between the years 2009 to 2012 were enrolled retrospectively to the study. Couples with male infertility who were treated with IMSI were included in the study. All their treatments were evaluated and divided into two subgroups: conventional IVF-ICSI treatment and their subsequent IMSI treatment. Demographic data, clinical parameters and outcome were recorded. The IMSI treatments were compared to previous non-IMSI treatments in terms of fertilization rates, cleavage rates, number of embryos and their quality, number of embryos transferred and pregnancy outcome.

MAIN RESULTS

Forty-two couples were reviewed. Basic characteristics of the groups were comparable. Fertilization and cleavage rates of the two groups were comparable. The embryos quality demonstrated a trend toward superior quality (grade 1-2) embryos in the IMSI versus ICSI (60% versus 47%; p = 0.07 and 53% versus 40%; p = 0.07), respectively. Implantation and clinical pregnancy rates were significantly superior in IMSI group (19.2% versus 7.8%; p = 0.042 and 41.3% versus 10.5%; p = 0.02, respectively). Miscarriage rate was significantly higher in conventional IVF-ICSI group (100% versus 15.8%; p = 0.04), and live birth rate was significantly higher in IMSI group (0 in conventional IVF-ICSI and 34.7% per transfer in IMSI group; p = 0.003).

CONCLUSION

IVF outcome of IMSI resulted in a higher implantation rate, pregnancy rate and most importantly delivery rate compare to non IMSI treated cycles.

Influence of temperature and sperm preparation on the quality of spermatozoa

This study investigated the effects of long-term (24h) in-vitro sperm incubation at room temperature (RT; 23°C) versus testis temperature (35°C) on various sperm-quality parameters. Semen samples (n=41) were prepared both by density-gradient centrifugation (DGC) and the swim-up technique in order to compare the influence of sperm preparation on sperm quality after incubation. Progressive motility and morphology were significantly higher after incubation at RT compared with 35°C (P<0.001 and P<0.01, respectively). The proportions of acrosome-reacted, apoptotic and dead spermatozoa were significantly lower in samples incubated for 24h at RT compared with 35°C (P<0.001, P=0.01 and P<0.001, respectively). The number of motile, morphologically normal, non-acrosome-reacted and nonapoptotic spermatozoa recovered after sperm preparation was significantly higher in DGC compared with swim-up samples (P<0.001). However, spermatozoa prepared by swim-up showed better survival after incubation compared with DGC-prepared spermatozoa, especially when incubated at 35°C. In conclusion, this study indicates a significantly better and longer preservation of sperm quality when incubation is performed at RT. These findings may convince laboratories to change the routinely used sperm storage conditions in order to maximize the quality of the prepared sperm sample.

Semen quality and prediction of IUI success in male subfertility: a systematic review

Many variables may influence success rates after intrauterine insemination (IUI), including sperm quality in the native and washed semen sample. A literature search was performed to investigate the threshold levels of sperm parameters above which IUI pregnancy outcome is significantly improved and/or the cut-off values reaching substantial discriminative performance in an IUI programme. A search of MEDLINE, EMBASE and Cochrane Library revealed a total of 983 papers. Only 55 studies (5.6%) fulfilled the inclusion criteria and these papers were analysed. Sperm parameters most frequently examined were: (i) inseminating motile count after washing: cut-off value between 0.8 and 5 million; (ii) sperm morphology using strict criteria: cut-off value ⩾5% normal morphology; (iii) total motile sperm count in the native sperm sample: cut-off value of 5-10 million; and (iv) total motility in the native sperm sample: threshold value of 30%. The results indicate a lack of prospective studies, a lack of standardization in semen testing methodology and a huge heterogeneity of patient groups and IUI treatment strategies. More prospective cohort trials and prospective randomized trials investigating the predictive value of semen parameters on IUI outcome are urgently needed. It is generally believed that intrauterine insemination (IUI) with homologous semen should be a first-choice treatment to more invasive and expensive techniques of assisted reproduction in cases of cervical, unexplained and moderate male factor subfertility. The rationale for the use of artificial insemination is to increase gamete density at the site of fertilization. Scientific validation of this strategy is difficult because literature is rather confusing and inconclusive. Many variables may influence success rates after IUI treatment procedures. It seems logical that sperm quality has to be one of the main determinants to predict IUI success. Clinical practice would benefit from the establishment of threshold levels for sperm parameters above which IUI pregnancy outcome is significantly improved and below which a successful outcome is unlikely. We performed a literature search to investigate if such threshold levels are known. Most striking were the lack of standardization in semen-testing methodology and the huge heterogeneity of patient groups and IUI treatment strategies. The four sperm parameters most frequently examined were: (i) inseminating motile count after washing: cut-off value between 0.8 and 5 million; (ii) sperm morphology using strict criteria: cut-off value >4% normal morphology; (iii) total motile sperm count in native sperm sample: cut-off value of 5-10 million; and (iv) total motility in native sperm sample: threshold value of 30%. This review identified an urgent need for more and better prospective cohort trials investigating the predictive value of semen parameters on IUI pregnancy rate.

Clinical management of male infertility in assisted reproduction: ICSI and beyond

The advent of in vitro fertilization and its augmentation with intracytoplasmic sperm injection (ICSI) has allowed a large number of couples suffering from moderate to severe male infertility, and also presenting with female pathologies, to achieve their reproductive dreams. Notwithstanding the existence of fundamental questions about the pathophysiological mechanisms leading to sperm dysfunction, and still unanswered concerns about health risks following ICSI, it appears that overall ICSI is safe and here to stay. Although on one hand ICSI possibly hampered advances of the knowledge in some areas of gamete biology and interaction, on the other it definitely gave impulse to studies designed to unveil the sperm contributions during and beyond fertilization, including the normalcy of the DNA/chromatin as well as molecular mechanisms of genetic/epigenetic control and nuclear organization status. In all, almost entering the fourth decade of assisted reproductive technologies, we should continue monitoring the safety of the technique and long-term development of offspring, whereas at the same time prioritizing areas of research addressing these fundamental questions.

Sperm chromatin integrity in young men with no experiences of infertility and men from idiopathic infertility couples

Damage to the genetic component of spermatozoa seems to play the main role in a majority of cases where current approaches fail to reveal the specific cause of male infertility. In this study, we compared semen quality in men assigned to two defined groups: men from couples with unexplained infertility - idiopathic infertility (A) and young men with no experiences of infertility (B). All samples were examined by standard ejaculate analysis and sperm chromatin structure assay (SCSA). Sperm chromatin damage was significantly higher in men from group A than in those from group B. Similar results were obtained by comparison of men from group A (all men were normozoospermic) with normozoospermic men from group B. According to these results, we can suppose that chromatin disorders may be the causal factor of subfertility or infertility in some of these men. No evidence for a strong association between chromatin disorders and standard parameters of ejaculates was found. We failed to confirm a relationship between smoking and sperm quality in men from any of the investigated groups. SCSA is a method that facilitates the identification of infertile men who otherwise show normal semen variables.

Standardization and quality control for the determination of alpha-glucosidase in seminal plasma

We attempted to provide an instruction for the standardization of alpha-glucosidase level determination and quality controls within the same laboratory and among different laboratories. Each of 51 semen samples was divided into two aliquots, centrifuging at 1000 g for 10 min or 3000 g for 15 min. The alpha-glucosidase level and sperm concentration of each sample were assayed. The alpha-glucosidase level in seminal plasma obtained at 3000 g for 15 min centrifugation was significantly lower than that at 1000 g for 10 min (p = 0.001). An additional 6 samples of seminal plasma with or without phenylmethylsulfonyl fluoride (PMSF), obtained at 3000 g for 15 min centrifugation, were frozen for 20 days, and each of 6 samples was determined for their alpha-glucosidase levels after thawing every other day. There was no significant difference between alpha-glucosidase levels in seminal plasma regardless of the presence of PMSF. The alpha-glucosidase level increased with the length of abstinence period. In conclusion, centrifugal velocity and abstinence time should be standardized in the alpha-glucosidase determination. Frozen seminal plasma may serve as the sample for quality control among clinical laboratories.

Rational diagnosis and treatment in infertility

Subfertility is a statistical concept. When a pregnancy has not been achieved within a year of unprotected intercourse, the odds are that an underlying pathological mechanism is at play. Advanced female age, longer duration and primary infertility, are important prognostic factors, suggestive of low fecundity and indicating a need for further diagnosis and treatment. Many diagnostic tests only have screening value and the only gold standards are hysteroscopy and laparoscopy. Severely impaired semen quality should lead to andrological work-up. Postcoital test and endometrial biopsy are obsolete. Treatment should preferably be aetiological, such as in anovulation, and sometimes also in endometriosis and tubal infertility. Primary treatment of male infertility is not proven to be advantageous. Conception-enhancing techniques such as intrauterine insemination (IUI), in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI), have shown to be effective. As a rule, and where possible, IUI is preferred and only if four to six cycles have failed should IVF be offered.

The Use of Semen Parameters to Identify the Subfertile Male in the General Population

AIMS

To present a structured review of the literature published on semen parameters and in vivo fertility potential and to establish fertility/subfertility thresholds for sperm morphology using Tygerberg strict criteria, sperm concentration, and sperm motility.

METHOD

The published literature comparing fertile and subfertile populations between 1983 and 2002 was reviewed.

RESULTS

A total of 265 articles were identified by the sourcing methodology, but only four articles provided data that could be tabulated and analyzed. Using receiver-operating characteristics curves, morphology proved to be the best predictor of subfertility in 2 of the 4 articles, with concentration and motility also showing good predictive power. The thresholds calculated ranged between 4 and 10% for morphology, between 13.5 x 10(6)/ml and 34 x 10(6)/ml for concentration, and between 32 and 52% for motility. A second set of much lower thresholds was calculated in three of the articles using either a 15 or 50% prevalence of subfertility in the population or the tenth percentile of the fertile population. The adjusted thresholds were between 3 and 5% for morphology, between 9 x 10(6)/ml and 20 x 10(6)/ml for concentration, and between 20 and 30% for motility.

CONCLUSIONS

Because these lower thresholds have a much higher positive predictive value, we suggest that thresholds of <5% normal sperm morphology, a concentration <15 x 10(6)/ml, and a motility <30% should be used to identify the subfertile male. The lower threshold for morphology also fits in vitro fertilization and intrauterine insemination data calculated previously. Using the parameters in combination increases the clinical value of semen analysis.

Isolated teratozoospermia and intrauterine insemination

OBJECTIVE

This study tests the hypothesis that IUI treatment in cases with isolated teratozoospermia (<10% normal forms using strict criteria, normal motility and normal count), results in a lower cumulative live birth rate compared to cases with normozoospermia.

DESIGN

A retrospective cohort study.

SETTING

An academic fertility center.

PATIENT(S)

Eight hundred seventy-two IUI cycles in 440 couples were analyzed.

INTERVENTION(S)

Couples (n = 440) were classified in three groups: normozoospermia (n = 213), isolated teratozoospermia (n = 104), and male factor infertility (n = 123).

MAIN OUTCOME MEASURE(S)

Live birth rate per cycle and cumulative live birth rate (CLBR).

RESULT(S)

The three groups were similar with regard to female age, female infertility factors, and ovarian response after hormonal stimulation. The overall CLBR after four cycles was 41.5%, and was significantly increased in the normozoospermic group (52.8%) when compared to the isolated teratozoospermia group (33.4%) and the male factor infertility group (31.4%).

CONCLUSION(S)

This study documents for the first time that the CLBR after four IUI cycles is significantly and similarly reduced in couples with isolated teratozoospermia as in couples with other sperm defects, when compared to couples with normozoospermia. As with couples with male factor infertility, couples with isolated teratozoospermia should be counseled about other treatment options such as IVF, as the CLBR after three IVF cycles is 70%-80% in our program.

Morphology of spermatozoa used in IVF and ICSI from oligozoospermic men

The purpose of this study was to determine morphology in human spermatozoa from men with oligozoospermia and correlate with the fertilization rate, embryo score and pregnancy rate after IVF and intracytoplasmic sperm injection (ICSI) respectively. The study group consisted of 125 couples where the male partner suffered from oligozoospermia. Fifty of these had IVF (group A). Seventy-five couples in whom ICSI had been performed made up group B. Sperm samples were assessed according to the WHO manual. For each male, morphology of spermatozoa was judged according to Krüger's strict criteria, WHO criteria and the teratozoospermia index (TZI). Oocyte monitoring was carried out according to a long down-regulation protocol using gonadotrophin-releasing hormone, recombinant FSH and human chorionic gonadotrophin. Embryos were transferred on day 2 after fertilization, with a maximum of three embryos. This study demonstrated no correlation between any of the morphological assessments of spermatozoa and the fertilization rate, embryo score and pregnancy rate, either after IVF or ICSI. Morphology in human spermatozoa according to Krüger's strict criteria, WHO criteria and the TZI had no predictive value for the outcome after either IVF or ICSI.

Semen quality and intrauterine insemination

There is good evidence in literature that intrauterine insemination (IUI) is the best first line treatment and most cost-effective procedure for moderate male factor subfertility. It seems very difficult to identify individual semen parameters predicting the likelihood of pregnancy after IUI. This can be explained by a lack of standardization of semen analysis, but many other methodological variables may also influence IUI success rates such as the patient selection, type of ovarian stimulation and number of inseminations per cycle. A review of the literature confirmed that sperm morphology using strict criteria and the inseminating motile sperm count (IMC) after sperm preparation are the two most important sperm parameters to assess the real impact of semen quality on IUI outcome. A universal threshold level above which IUI can be performed with acceptable pregnancy rates has not been determined yet, although IUI success seems to be impaired with <5% normal spermatozoa and an IMC of <1 x 10(6). Until now, no method of sperm preparation has been shown to be superior with regard to pregnancy rate after IUI. Whether supplementation of culture media with substances such as antioxidants and platelet activating factor may improve the results remains the subject of further research.

Assessment of human sperm morphology by strict criteria: comparison of wet preparation versus stained with the modified Diff-Quik method

Routine semen examination remains an important tool for the diagnosis and treatment in human subfertility. Of all semen parameters, sperm morphology seems to be one of the most powerful indicators of a man's fertilizing potential in vitro and in vivo. Lack of standardization of sperm morphology assessments remains the main reason for the usefulness of this parameter. The aim of this study was to analyze the agreement between the wet-stained preparations versus those stained with modified Diff-Quik for sperm morphology. A total of 100 unselected semen samples from infertile couples were analyzed. Sperm morphology was evaluated with unstained specimens and following modified Diff-Quik staining according to the strict (Kruger classification) criteria by two different examiners (intralaboratory blind assessment). Mean percentages of morphologically normal spermatozoa were identical on wet and stained preparation slides (4.79 vs. 4.61, p >.05). Wide divergence of results was found with respect to the percentage of sperm with head and midpiece defects with the two different preparations (p >.001). The percentage of sperm tail defects was similar in both methods (p >.05). Simple linear regression analysis between the two methods revealed very good correlation for the morphologically normal spermatozoa (r =.83), but poor correlation for the sperm head, midpiece, and tail defects (r =.25,.25, and.28, respectively). Wet preparation is suitable only for the morphologically normal spermatozoa, but to determine the percentage of the defective spermatozoa, staining the smear is recommended.

[Predictive value of non-automated spermatic parameters and automated kinetic parameters on cleavage rate in fertilization in vitro]

The aim of this work was to determine retrospectively in 114 couples the predictive value of semen analysis for the in vitro fertilization (IVF) outcome when sperm evaluation before IVF was assessed by either conventional parameters or a Hamilton-Thorne automated motility analyser. A backward logistic regression analysis was used to study the relative contribution of each conventional or computerized parameter. Computerized sperm values were the worst index for predicting oocyte fertilization. However a tight relationship between morphology and cleavage ratio was observed. Using ROC analysis, under a 18% threshold, cleavage failure was noted in 71% of couples undergoing an IVF program. This study indicates that morphology is the best parameter for predicting cleavage failure.

Intra- and inter-laboratory variability in the assessment of sperm morphology by strict criteria: impact of semen preparation, staining techniques and manual versus computerized analysis

We designed prospective studies to compare manual and computerized analysis of sperm morphology by strict criteria using different semen processing and staining techniques. A total of 54 semen samples were studied; slides were prepared from each subject from liquefied semen and after washing, and stained with Diff-Quik or Papanicolaou. An intra-laboratory, blind assessment was performed manually (two observers) and using a computerized analyser (two readings). This demonstrated a very good correlation between manual analysis of liquefied and washed samples with both staining techniques [intraclass coefficient (ICC) = 0.93 and 0.83]. Greater agreement was observed between computerized readings (washed samples) of Diff-Quik (ICC = 0.93) than of Papanicolaou-stained slides (ICC = 0.66). An excellent intra-laboratory correlation was observed for within-computer readings (ICC = 0.93). There was moderate agreement between inter-laboratory computer readings (two centres, ICC = 0.72). Although there was lower inter-laboratory agreement for manual and manual versus computer readings, overall results of all manual and computer analyses showed good agreement (ICC = 0.73). Diff-Quik staining is reliable for both manual (liquefied) and computer (washed) analysis of strict sperm morphology. Intra- and inter-computer analyses using this method reached satisfactory levels of agreement. There is still high inter-laboratory variability for the manual method.