Chromosome analysis of epididymal and testicular sperm in azoospermic patients undergoing ICSI

Reproductive and obstetric outcomes in TESE-ICSI cycles: A comparison between obstructive and non-obstructive azoospermia

PURPOSE

Comparison of intracytoplasmic sperm injection cycles with testicular sperm extraction in obstructive azoospermia and non-obstructive azoospermia are limited, and few studies have addressed obstetric and neonatal outcomes.

DESIGN

This study analyzed couples who underwent testicular sperm extraction-intracytoplasmic sperm injection cycles for obstructive azoospermia and non-obstructive azoospermia to determine whether impaired spermatogenesis in non-obstructive azoospermia patients would lead to worse reproductive outcomes and higher rates of pregnancy complications and fetal anomalies. This study is a retrospective, single-center analysis of all testicular sperm cycles performed between January 1, 2001 and December 31, 2020.

RESULTS

A total of 392 couples were considered in the study, leading to 1066 induction cycles, 620 (58.2%) from patients with obstructive azoospermia and 446 (41.8%) from non-obstructive azoospermia. The cumulative delivery rate did not significantly differ between the two groups (34% vs. 31%; p = 0.326). The miscarriage rate was similar between obstructive azoospermia and non-obstructive azoospermia patients. Fertilization rate instead showed a statistically significant difference (obstructive azoospermia: 66.1 ± 25.7 vs. non-obstructive azoospermia: 56.1 ± 27.0; p < 0.001). The overall maternal complication rate in the non-obstructive azoospermia group was higher (10.7% vs. 18.4%; p = 0.035), but there was no statistical significance for each pathology. There was no statistical difference in gestational age between the two groups for both single and twin pregnancies. Seven cases of congenital defects occurred in the obstructive azoospermia group, while two cases occurred in the non-obstructive azoospermia group.

CONCLUSIONS

Despite impaired spermatogenesis in non-obstructive azoospermia patients, there were no substantial differences in reproductive outcomes compared to patients with obstructive azoospermia, even in terms of obstetric safety and neonatal well-being.

Surgically retrieved spermatozoa for ICSI cycles in non-azoospermic males with high sperm DNA fragmentation in semen

Intracytoplasmic sperm injection (ICSI) using surgically retrieved spermatozoa outside the classic context of azoospermia has been increasingly used to overcome infertility. The primary indications include high levels of sperm DNA damage in ejaculated spermatozoa and severe oligozoospermia or cryptozoospermia, particularly in couples with ICSI failure for no apparent reason. Current evidence suggests that surgically retrieved spermatozoa for ICSI in the above context improves  outcomes, mainly concerning pregnancy and miscarriage rates. The reasons are not fully understood but may be related to the lower levels of DNA damage in spermatozoa retrieved from the testis compared with ejaculated counterparts. These findings are consistent with the notion that excessive sperm DNA damage  can be a limiting factor responsible for the failure to conceive. Using testicular in preference of low-quality ejaculated spermatozoa bypasses post-testicular sperm DNA damage caused primarily by oxidative stress, thus increasing the likelihood of oocyte fertilization by genomically intact spermatozoa. Despite the overall favorable results, data remain limited, and mainly concern males with confirmed sperm DNA damage in the ejaculate. Additionally, information regarding the health of ICSI offspring resulting from the use of surgically retrieved spermatoa of non-azoospermic males is still lacking. Efforts should be made to improve the male partner's reproductive health for safer ICSI utilization. A comprehensive andrological evaluation aiming to identify and treat the underlying male infertility factor contributing to sperm DNA damage is essential for achieving this goal.

The significance of karyotyping and azoospermia factor analysis in patients with nonobstructive azoospermia or oligozoospermia

OBJECTIVE

We present our study about the significance of karyotyping and azoospermia factor(AZF) analysis in patients with azoospermia or oligozoospermia.

MATERIALS AND METHODS

We retrospectively reviewed 141 Taiwanese patients with nonobstructive azoospermia and 45 Taiwanese patients with oligozoospermia at MacKay Memorial Hospital, Taiwan, from 2010 to 2021 to determine the significance of karyotyping and azoospermia factor analysis. The karyotyping was analyzed using the Giemsa banding method. The AZF microdeletions were determined using multiplex polymerase chain reaction using primers specifically flanking the AZF subregions.

RESULTS

We found that 7.80% of patients with nonobstructive azoospermia had AZF microdeletions and 19.86% of patients with nonobstructive azoospermia had chromosomal anomalies or polymorphic variations. Furthermore, 4.44% of patients with oligozoospermia had AZF microdeletions, and 4.44% of patients with oligozoospermia had chromosomal anomalies or polymorphic variations.

CONCLUSION

In this study, 25.53% of patients with nonobstructive azoospermia and 8.88% of patients with oligozoospermia had abnormal findings. The significance of karyotyping and azoospermia factor analysis is more critical in patients with nonobstructive azoospermia than patients with oligozoospermia. Both karyotyping and AZF analysis could prevent delayed treatment for male infertility through accurate diagnosis and appropriate treatment. The number of our patients with AZFc microdeletion was also higher than that of patients with AZFa or AZFb. The spermatogenic potential may gradually decline in patients with AZFc microdeletion. The earlier is the diagnosis, the earlier will be the retrieval of testicular spermatozoa.

Genetics of Male Infertility - Present and Future: A Narrative Review

Infertility affects 8%–12% of couples worldwide with a male factor contributing to nearly 50% of couples either as a primary or contributing cause. Several genetic factors that include single-gene and multiple-gene defects associated with male infertility were reported in the past two decades. However, the etiology remains ambiguous in a majority of infertile men (~40%). The objective of this narrative review is to provide an update on the genetic factors associated with idiopathic male infertility and male reproductive system abnormalities identified in the last two decades. We performed a thorough literature search in online databases from January 2000 to July 2021. We observed a total of 13 genes associated with nonobstructive azoospermia due to maturation/meiotic arrest. Several studies that reported novel genes associated with multiple morphological abnormalities of the sperm flagella are also discussed in this review. ADGRG2, PANK2, SCNN1B, and CA12 genes are observed in non-CFTR-related vas aplasia. The genomic analysis should be quickly implemented in clinical practice as the detection of gene abnormalities in different male infertility phenotypes will facilitate genetic counseling.

Advances in sperm analysis: techniques, discoveries and applications

Infertility affects one in six couples worldwide, and fertility continues to deteriorate globally, partly owing to a decline in semen quality. Sperm analysis has a central role in diagnosing and treating male factor infertility. Many emerging techniques, such as digital holography, super-resolution microscopy and next-generation sequencing, have been developed that enable improved analysis of sperm motility, morphology and genetics to help overcome limitations in accuracy and consistency, and improve sperm selection for infertility treatment. These techniques have also improved our understanding of fundamental sperm physiology by enabling discoveries in sperm behaviour and molecular structures. Further progress in sperm analysis and integrating these techniques into laboratories and clinics requires multidisciplinary collaboration, which will increase discovery and improve clinical outcomes.

Sperm DNA Fragmentation: A New Guideline for Clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Germ cell loss in Klinefelter syndrome: When and why?

Klinefelter syndrome (KS) is a quite common disorder with an incidence of 1-2 in 1,000 new-born males. Most patients are diagnosed in the light of a clinical checkup when consulting a fertility clinic with an unfulfilled child wish. Infertility in KS patients is caused by a massive germ cell loss, leading to azoospermia in more than 90% of the adult patients. Most seminiferous tubules in the adult KS testis are degenerated or hyalinized and testicular fibrosis can be observed, starting from puberty. However, focal spermatogenesis can be found in the testis of some patients. This offers the opportunity to extract spermatozoa from the testis by testicular sperm extraction (TESE). Nevertheless, TESE is only successful in about half of the KS adults seeking to father children. The reason for the germ cell loss remains unclear. To date, it is still debated whether the testicular tissue changes and the germ cell loss seen in KS is directly caused by an altered X-linked gene expression, the altered somatic environment, or a deficiency in the germ cells. In this review, we provide an overview of the current knowledge about the germ cell loss in KS patients.

Genetic Landscape of Nonobstructive Azoospermia and New Perspectives for the Clinic

Nonobstructive azoospermia (NOA) represents the most severe expression of male infertility, involving around 1% of the male population and 10% of infertile men. This condition is characterised by the inability of the testis to produce sperm cells, and it is considered to have an important genetic component. During the last two decades, different genetic anomalies, including microdeletions of the Y chromosome, karyotype defects, and missense mutations in genes involved in the reproductive function, have been described as the primary cause of NOA in many infertile men. However, these alterations only explain around 25% of azoospermic cases, with the remaining patients showing an idiopathic origin. Recent studies clearly suggest that the so-called idiopathic NOA has a complex aetiology with a polygenic inheritance, which may alter the spermatogenic process. Although we are far from a complete understanding of the molecular mechanisms underlying NOA, the use of the new technologies for genetic analysis has enabled a considerable increase in knowledge during the last years. In this review, we will provide a comprehensive and updated overview of the genetic basis of NOA, with a special focus on the possible application of the recent insights in clinical practice.

Extended indications for sperm retrieval: summary of current literature

Sperm retrieval combined with intracytoplasmic sperm injection (ICSI) is the treatment of choice for couples with untreatable azoospermia-related infertility. However, an increasing body of evidence has been mounting, suggesting that ICSI with testicular sperm instead of ejaculated sperm (when both are available) increases pregnancy outcomes in some specific scenarios. This has led to the exploration of extended indications for sperm retrieval. This review summarizes the current literature concerning sperm retrieval and ICSI for non-azoospermic men with elevated sperm DNA fragmentation, oligozoospermia, and cryptozoospermia.

Use of testicular sperm for intracytoplasmic sperm injection in men with high sperm DNA fragmentation: a SWOT analysis

Spermatozoa retrieved from the testis of men with high levels of sperm DNA fragmentation (SDF) in the neat semen tend to have better DNA quality. Given the negative impact of SDF on the outcomes of Assisted Reproductive Technology (ART), an increased interest has emerged about the use of testicular sperm for intracytoplasmic sperm injection (Testi-ICSI). In this article, we used a SWOT (strengths, weaknesses, opportunities, and threats) analysis to summarize the advantages and drawbacks of this intervention. The rationale of Testi-ICSI is bypass posttesticular DNA fragmentation caused by oxidative stress during sperm transit through the epididymis. Hence, oocyte fertilization by genomically intact testicular spermatozoa may be optimized, thus increasing the chances of creating a normal embryonic genome and the likelihood of achieving a live birth, as recently demonstrated in men with high SDF. However, there is still limited evidence as regards the clinical efficacy of Testi-ICSI, thus creating opportunities for further confirmatory clinical research as well as investigation of Testi-ICSI in clinical scenarios other than high SDF. Furthermore, Testi-ICSI can be compared to other laboratory preparation methods for deselecting sperm with damaged DNA. At present, the available literature supports the use of testicular sperm when performing ICSI in infertile couples whose male partners have posttesticular SDF. Due to inherent risks of sperm retrieval, Testi-ICSI should be offered when less invasive treatments for alleviating DNA damage have failed. A call for continuous monitoring is nonetheless required concerning the health of generated offspring and the potential complications of sperm retrieval.

Revisiting aneuploidy profile of surgically retrieved spermatozoa by whole exome sequencing molecular karyotype

Previous studies, including our own, have reported that spermatozoa isolated from the testis have remarkably higher occurrence of aneuploidy once isolated from azoospermic men. This notion, however, did not translate into a lower pregnancy rate nor a greater proportion of miscarriages. Indeed, ICSI offspring generated from surgically retrieved gametes did not suffer from increased karyotypic aneuploidy than children generated from ejaculated specimens. In recent years, aneuploidy assessments on a larger number of cells and utilizing more chromosome probes have reported a progressive decrease in chromosomal aberrations in spermatozoa directly retrieved from the seminiferous tubules. In light of the availability of more accurate molecular genetic techniques, we have decided to challenge the notion that sampling epididymal and testicular tissues yields spermatozoa with higher incidence of aneuploidy than those retrieved in the ejaculate. In a retrospective manner, we have carried out an analysis by FISH with 9 chromosome probes on at least 1000 cells from the ejaculates of 87 consenting men and the specimens of 6 azoospermic men, while spermatozoa of fertile donors were used as control. Aneuploidy by FISH yielded 0.9% for the donor control but rose in the study group to 3.6% in the ejaculated, 1.2% for the epididymal, and 1.1% for testicular spermatozoa. There were no differences in autosomal or gonosomal disomies, nor nullisomies. In this group, once the specimens of these men were used for ICSI, ejaculated spermatozoa yielded a 22% clinical pregnancy rate that resulted in 62.5% pregnancy loss. The surgically retrieved specimens yielded a 50% clinical pregnancy rate that progressed to term. To confirm our findings, in a prospective analysis, DNA sequencing was carried out on the ejaculates and surgical samples of 22 men with various spermatogenic characteristics. In this comparison, the findings were similar with actually a higher incidence of aneuploidy in the ejaculated spermatozoa (n = 16) compared to those surgically retrieved (n = 6) (P<0.0001). For this group, the clinical pregnancy rate for the ejaculated specimens was 47.2% with 29.4% pregnancy loss, while the surgically retrieved yielded a 50% clinical pregnancy rate, all progressing to term. A subsequent prospective combined assessment on ejaculated and surgically retrieved spermatozoa by FISH and NGS was performed on non-azoospermic men with high DNA fragmentation in their ejaculate. The assessment by FISH evidenced 2.8% chromosomal defects in the ejaculated and 1.2% in testicular biopsies while by NGS became 8.4% and 1.3% (P = 0.02), respectively. Interestingly, we evidenced a pregnancy rate of 0% with ejaculated while 100% with the testicular spermatozoa in this latter group. This indicates that improved techniques for assessing sperm aneuploidy on a wider number of cells disproves earlier reports and corroborates the safe utilization of testicular spermatozoa with a positive impact on chances of pregnancy.

Long-term clinical outcomes of testicular sperm extraction and intracytoplasmic sperm injection for infertile men

Purpose

To find the best methods to achieve the highest pregnancy and birth rates for couples needing testicular sperm extraction (TESE)‐intracytoplasmic sperm injection (ICSI).

Methods

Retrospectively studied were 801 patients with male factor infertility who had undergone TESE‐ICSI between April, 1996 and July, 2016 and who had been categorized into four groups: obstructive azoospermia (OA); non‐obstructive azoospermia (NOA); Klinefelter syndrome (KS); and cryptozoospermia (Crypt). The sperm retrieval rate, hormone levels, fertilization rate (FR), pregnancy rate (PR), and birth rate (BR) after ICSI among three groups were compared: fresh testicular sperm (FS)‐fresh oocytes (FO) (Group I); frozen‐thawed testicular sperm‐FO (Group II); and FS‐vitrified‐warmed oocytes (Group III).

Results

The testicular sperm recovery rate was 57.8% (463/801): 89.6% in the Crypt, 97.1% in the OA, 28.9% in the NOA, and 42.2% in the KS groups. The follicle‐stimulating hormone levels were significantly higher in the NOA and KS groups and the testosterone levels were significantly lower in the KS group. The FR, PR, and BR were: 65.2%, 43.2%, and 28.5% in group I; 59.2%, 33.4%, and 18.7% in group II; and 56.4%, 33.8%, and 22.1% in group III.

Conclusion

Intracytoplasmic sperm injection with FS‐FO achieved the best PR and BR. It should be considered what to do in cases with no testicular sperm by TESE. The authors hope that ICSI with donor sperm will be allowed in Japan in the near future.

Comparison of intracytoplasmic sperm injection with testicular spermatozoa success in infertile men with obstructive and non-obstructive azoospermia; a retrospective analysis

The aim of this study was to compare the outcome of intracytoplasmic sperm injection (ICSI) and embryo transfer between couples with infertility due to male non-obstructive azoospermia (NOA) and obstructive azoospermia (OA). A retrospective analysis of 234 couples with azoospermia who were treated by ICSI and embryo transfer between January 2007 and October 2010 was performed. There were 61 couples in NOA group and 173 couples in OA group. Fertilization rates, pregnancy and clinical pregnancy rates were the main outcome measures. The number of retrieved mature oocytes, injected oocytes, metaphase II (MII) oocytes, two distinct pronuclei oocytes, cleavage embryos and embryos transferred was not significantly different between the groups. The fertilization rate was significantly lower in NOA group when compared to OA group (56.2 vs. 66.7%, respectively; p = 0.013) and the pregnancy rate was significantly lower in NOA group than OA group (36.1 vs. 50.9%, respectively; p = 0.046). The clinical pregnancy rates were not statistically different between the patients with NOA and OA azoospermia groups (24.6 vs. 36.4%, respectively; p = 0.09). This study suggests that ICSI and embryo transfer together with testicular sperm extraction results in statistically significant lower fertilization and pregnancy rates in men with NOA when compared to men with OA.

Cohort study of perinatal outcomes of children born following surgical sperm recovery

There is a relative paucity of data on perinatal outcomes following Intracytoplasmic Sperm Injection using surgically retrieved sperm. In this retrospective cohort study, data were collected on couples who conceived following Intracytoplasmic Sperm Injection using surgically retrieved sperm from 1996 to 2014. Outcome measures included live birth, miscarriage, congenital abnormality, birthweight, gestation at delivery, stillbirth and neonatal death. Outcome measures were compared according to male diagnosis and sperm source. Live birth rates were similar between groups (obstructive azoospermia 90%, non-obstructive azoospermia 83%, p = 0.55). There was a trend towards higher miscarriage rates in the non-obstructive azoospermia group (17% versus 9%, p = 0.45). Other perinatal outcomes were similar between groups. In those with obstructive azoospermia, live birth rates were similar regardless of source of sperm (epididymal 89%, testicular 91%, p = 0.79). Median gestation at delivery was earlier in the epididymal sperm group (39 weeks versus 40 weeks, p = 0.02). Other perinatal outcomes were unaffected by sperm source. Overall these results are reassuring, suggesting high live birth rates regardless of diagnosis or sperm source, although there may be higher miscarriage rates in cases of non-obstructive azoospermia. Other perinatal outcomes were not affected by diagnosis or sperm source.

ICSI outcomes in men undergoing TESE for azoospermia and impact of maternal age

This retrospective study compared clinical outcomes in men with obstructive and nonobstructive azoospermia after ICSI following testicular sperm extraction and the influence of maternal age. Fertilisation rates, embryo quality, pregnancy rates, miscarriage rates and live birth rates were evaluated. Men with obstructive azoospermia (OA) had significantly higher rates of diploid fertilisation and clinical pregnancy than men with nonobstructive azoospermia (NOA), but miscarriage rates and live birth rates were not significantly different. The higher rates of fertilisation, embryo quality and clinical pregnancy in men with OA were statistically significant when their female partners were <35 years but results were similar in both groups when female partners ≥35 years. Although the OA group had better overall quality embryos than the NOA group when maternal age was <35 years, embryologists can select the morphologically better embryos for transfer, eliminating the effect of embryo quality differences present in these two groups. Understanding more about factors that affect TESE/ICSI outcomes will not only help us predict patients' outcomes but it can help us educate and better counsel our patients.

Shedding Light on the Nature of Seminal Round Cells

INTRODUCTION

In this investigation we assess the incidence of round cells (RCs) in semen samples in our infertile patient population and their significance on intracytoplasmic sperm injection (ICSI) cycle outcomes. We also evaluate the usefulness of RCs as indicators of bacterial infection and highlight the origin of this cell-type, as well as its role in the human ejaculate.

PATIENTS AND METHODS

In a prospective fashion, a total of 4,810 ejaculated samples were included in the study during a period of 24 months. RCs were characterized for white blood cell (WBC) components versus exfoliated germ cells by testing for multiple markers of ploidy as well as protamine assays. Cases displaying ≥ 2 x 106/ml RCs were screened for bacteria. Raw specimens containing RC were processed by peroxidase and other leukocyte assays, specific stains for protamines were used to identify spermiogenic stage, aneuploidy (FISH) assessment was carried out, and the presence of various Sertoli-cell cytoplasmic remnants was analyzed to identify and characterize immature germ cells. The effect of RC on clinical outcome was assessed in specimens used for ICSI.

RESULTS

The average age of the men involved was 39.2 ± 7 years. Semen samples had a mean concentration of 40.7 ± 31 x 106/ml, motility of 42.6 ± 35%, and morphology of 2.3 ± 2%. RCs were identified in 261 specimens, representing a proportion of 5.4%. Men with RCs had comparable age but lower sperm concentration and morphology than the control group (P<0.001). The aneuploidy rate of 4.3% in RCs group was remarkably higher than the control group (2.3%; P<0.001). Sperm aneuploidy rate positively correlated with the number of RCs (P<0.001). Of 44 men, 17 of them in 18 cycles had up to 1.9 x 106/ml RCs without affecting fertilization and clinical pregnancy rates when compared to controls (n = 365 cycles). In 27 men undergoing 33 ICSI cycles with ≥ 2 x 106/ml RCs, the fertilization rate trended lower and the miscarriage rate was significantly increased (P = 0.05). There was lack of correlation between RC and bacteriological growth. Specific markers indicated that seminal RCs are mostly immature germ cells encased in the remnants of Sertoli cell cytoplasm. Moreover, their modest protamine content and their haploid status confirm that they are post-meiotic. Sequential observation in the same man showed that RC episodes were followed by an amelioration of semen parameters, and interestingly, the episodic occurrence of RCs often coincides with flu season peaks.

CONCLUSIONS

Seminal RCs are not a marker of infectiousness but rather a transient indicator of spermatogenic insult that possibly occurs in most men following a mild and transient ailment such as the flu.

Increased chromosome 16 disomy rates in human spermatozoa and recurrent spontaneous abortions

OBJECTIVE

To investigate if unexplained recurrent spontaneous abortions (RSA) are associated with increased rates of aneuploidy in spermatozoa of RSA partners ("RSA-men").

DESIGN

Case-control study.

SETTING

Academic research center.

PATIENT(S)

Patients enrolled at the Hormone and Fertility Center and controls at the Department of Urology (LMU-Munich).

INTERVENTION(S)

Sperm samples of 11 partners of unexplained RSA cases evaluated for elevated diploidy and disomy levels of chromosomes 1-22, X, and Y by multicolor sperm fluorescence in situ hybridization (FISH).

MAIN OUTCOME MEASURE(S)

Aneuploidy rates obtained in RSA-men compared with controls from the literature and internally; an increase of the aneuploidy rate was considered statistically significant, when it differed ≥ 2 standard deviations from the mean baseline level in controls.

RESULT(S)

Our sperm FISH data on RSA men showed increased disomy rates for at least three chromosomes in more than 60% of patients but no statistically significant increase of the overall mean sperm disomy or diploidy rate. In particular, meiotic errors involving chromosome 16 contributed to increased sperm disomy in more than 60% of our patients.

CONCLUSION(S)

These data suggest that among paternal meiotic errors nondisjunction of chromosome 16 might have similar relative influence on fetal aneuploidy compared with maternal chromosome 16 disomy.

Implication of sperm chromosomal abnormalities in recurrent abortion and multiple implantation failure

Currently, some infertility treatment centres provide sperm karyotype analysis, although the impact of sperm chromosomal abnormalities on fertility is not yet fully understood. Several studies using fluorescence in-situ hybridization (FISH) to analyse sperm chromosomal constitution discovered that the incidence of aneuploidy is increased in individuals with a history of repeated abortion or implantation failure and is even higher in cases of oligoasthenoteratozoospermia (OAT), abnormal somatic karyotype or in spermatozoa retrieved directly from the testis or epididymis, showing that the application of FISH in these cases may be of some benefit for improving the reproductive outcome. This article presents the results of clinical trials of FISH analysis on spermatozoa, the medical indications for performing this examination, its results in infertile patients and the advantages when performing genetic counselling prior to treatment. Also discussed is the possibility of applying the latest techniques of genetic analysis in these cases and the potential benefits for improving the prognosis of male infertility.

Surgical management of nonobstructive azoospermia

Nonobstructive azoospermia (NOA) is characterized by the complete absence of sperm in the ejaculate due to testicular failure. The evaluation and management of patients with NOA offer a challenge to the reproductive urologist. In the era of in vitro fertilization with intracytoplasmic sperm injection, surgical sperm extraction techniques can afford men with NOA biologic paternity. To provide a comprehensive review of surgical sperm retrieval approaches in the patient with NOA emphasizing complications, success rates and outcome optimization, a Medline search was conducted querying surgical approaches used to manage NOA. Four sperm extraction techniques are described including: testicular sperm aspiration, testicular sperm extraction, fine needle aspiration mapping and microdissection testicular sperm extraction. In addition, the roles for pre-extraction varicocelectomy and sperm cryopreservation are discussed. The management of NOA continues to evolve as newer tools become available. Several modalities of sperm acquisition exist. An understanding of their complications and success rates is fundamental to the treatment of NOA.

Genetics and male infertility

The goal of this review is to explain the requirement for understanding the genetic structure of infertility arising from male factor and to discuss the essentials of these genetic elements (2). The majority of the population is affected by this disorder caused by male factor infertility (1); but the etiologies are still unknown. After the primary genetic structure in infertile phenotypes is searched, an evaluation can be made. Thus the reasons causing infertility can be discovered and patients can benefit from effective therapies (1). Publications about male infertility within the recent 10 years in the Pubmed database were discussed (1). There are some approachments for describing the function of specific genes, but no adequate study is present to be useful for diagnosing and treating male infertility (1). Male fertility and fertility in offspring of males are considerably affected by the exact transition of epigenetic information (1). When the genetic factors playing a role in male infertility were analysed, significant steps will be taken for treating patients and determining the reasons of idiopathic infertility (1). Developments in technology associated with the impact of genetics may enable to specify the etiology of male infertility by determining specific infertile phenotype marks (1).

Safety of intracytoplasmic sperm injection

Early follow-up studies of IVF children showed that the frequency of birth anomalies resembled those arising with natural conception. More detailed analyses confirmed these findings, reinforcing the concept of the preimplantation period as teratologically "safe." The use of intracytoplasmic sperm injection (ICSI) to achieve fertilization introduced another variable.ICSI's safety has often been criticized because the fertilizing spermatozoon neither binds to the zona pellucida nor fuses with oolemma. Bypassing these physiologic steps together with the arbitrary selection of the spermatozoon has been reason for concern. Thus far, ICSI offspring undergoing adolescence and beyond has provided sufficient information to reassure these qualms. In fact, the health of the offspring generated through ICSI, once taken into consideration the gestational order, the age and the genetic makeup of the couples are generally reassuring.

Treatment of male infertility

Major difficulties exist in the accurate and meaningful diagnosis of male reproductive dysfunction, and our understanding of the epidemiology and etiology of male infertility has proven quite complex.The numerous spermatozoa produced in mammals and other species provides some degree of protection against adverse environmental conditions represented by physical and chemical factors that can reduce reproductive function and increase gonadal damage even resulting in testicular cancer or congenital malformations. The wide fluctuations of sperm production in men, both geographical and temporal, may reflect disparate environmental exposures, occurring on differing genetic backgrounds, in varying psychosocial conditions, and leading to the diversified observed outcomes.Sperm analysis is still the cornerstone in diagnosis of male factor infertility, indeed, individually compromised semen paramaters while adequately address therapeutic practices is progressively flanked by additional tests. Administration of drugs, IUI, correction of varicocele, and, to a certain extent, IVF although they may not be capable of restoring fertility itself often result in childbearing.

Azoospermia due to spermatogenic failure

This article summarizes the current literature regarding azoospermia caused by spermatogenic failure. The causes and genetic contributions to spermatogenic failure are reviewed. Medical therapies including use of hormonal manipulation, whether guided by a specific abnormality or empiric, to induce spermatogenesis are discussed. The role of surgical therapy, including a discussion of varicocelectomy in men with spermatogenic failure, as well as an in-depth review of surgical sperm retrieval with testicular sperm extraction and microdissection testicular sperm extraction, is provided. Finally, future directions of treatment for men with spermatogenic failure are discussed, namely, stem cell and gene therapy.

Cryopreservation of testicular and epididymal sperm: techniques and clinical outcomes of assisted conception

The introduction of the technique of intracytoplasmic sperm injection to achieve fertilization, especially using surgically retrieved testicular or epididymal sperm from men with obstructive or non-obstructive azoospermia, has revolutionized the field of assisted reproduction. The techniques for the retrieval of spermatozoa vary from relatively simple percutaneous sperm aspiration to open excision (testicular biopsy) and the more invasive Micro-TESE. The probability of retrieving spermatozoa can be as high as 100% in men with obstructive azoospermia (congenital bilateral absence of the vas deferens, status post-vasectomy). However, in nonobstructive azoospermia, successful sperm retrieval has been reported in 10-100% of cases by various investigators. The surgical retrieval and cryopreservation of sperm, especially in men with non-obstructive azoospermia, to some extent ensures the availability of sperm at the time of intracytoplasmic sperm injection. In addition, this strategy can avoid unnecessary ovarian stimulation in those patients intending to undergo in vitro fertilization-intracytoplasmic sperm injection with freshly retrieved testicular sperm when an absolute absence of sperm in the testis is identified. Several different methods for the cryopreservation of testicular and epididymal sperm are available. The choice of the container or carrier may be an important consideration and should take into account the number or concentration of the sperm in the final preparation. When the number of sperm in a testicular biopsy sample is extremely low (e.g., 1-20 total sperm available), the use of an evacuated zona pellucida to store the cryopreserved sperm has been shown to be an effective approach.

Genetic evaluation of the azoospermic or severely oligozoospermic male

PURPOSE OF REVIEW

The purpose of this review is to provide a contemporary overview of the genetic evaluation of azoospermic or severely oligozoospermic men.

RECENT FINDINGS

Genetic tests should be selected based upon the initial clinical evaluation. Patients with vasal agenesis or unexplained obstructive azoospermia and low semen volume should be tested for abnormalities of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Cytogenetic testing (karyotype) and Y chromosome microdeletion (YCMD) screening are indicated in all cases when severely impaired sperm production due to testicular failure is suspected. Mutational screening of commonly implicated genes should be considered when congenital hypogonadotropic hypogonadism is clinically apparent.

SUMMARY

A clinically directed genetic evaluation is indicated in all azoospermic and severely oligozoospermic men. Such genetic testing is informative about the cause of infertility, the prognosis for biological paternity using assisted reproduction, and the risks of genetic abnormalities and disease in offspring. Future genetic testing may reveal a predisposition for medical conditions beyond infertility that warrant clinical management.

Testicular sperm aneuploidy in non-obstructive azoospermic patients

BACKGROUND

Non-obstructive azoospermic (NOA) men can father children after testicular sperm extraction (TESE). Previous studies suggest that they may be at risk of producing chromosomally abnormal spermatozoa, but the number of sperm analysed per patient was usually very low.

METHODS

Multicolour fluorescence in situ hybridization was used for detection of chromosome 13, 15, 16, 18, 21, 22, X and Y disomy and diploidy in sperm obtained from NOA men (n = 17) and control donors (n = 10). At least 500 testicular sperm were scored in each patient to increase the precision of our study.

RESULTS

The mean frequency of overall disomy (2.32%) and diploidy (0.80%) found in 13 689 testicular spermatozoa of NOA patients was significantly higher than in the ejaculated sperm of normospermic control donors, disomy (0.62%) and diploidy (0.29%). A highly significant increase in frequencies of chromosome 15, Y and overall disomy (P < 0.001), and a significant increase in disomy of chromosome 13 (P = 0.002), 16 (P = 0.031) and 21 (P = 0.018), overall diploidy (P = 0.031) and diploidy caused by errors in meiosis I (P = 0.011) were observed in the NOA group.

CONCLUSIONS

Testicular sperm samples of NOA patients show a higher incidence of numerical chromosomal abnormalities compared with ejaculated sperm of control donors. Appropriate genetic counselling is necessary in NOA men undergoing TESE.

A comparison of ejaculated and testicular spermatozoa aneuploidy rates in patients with high sperm DNA damage

Testicular spermatozoa are utilized to achieve pregnancy in couples with severe male factor infertility. Several studies suggest that aneuploidy rates in spermatozoa are elevated at the testicular level in infertile patients compared to ejaculates of normal controls. However, essential data regarding aneuploidy rates between ejaculated and testicular spermatozoa in the same individuals is lacking. The purpose of our study was to compare aneuploidy rates at the testicular and post-testicular level from the same patients with persistently high sperm DNA damage. Ejaculates and testicular biopsies were obtained from eight patients with persistently high DNA damage (>30%). Both ejaculated and testicular samples were analyzed for sperm DNA damage and sperm aneuploidy for chromosomes 13, 18, 21, X, and Y. In addition, semen samples from ten normozoospermic men presenting for fertility evaluation served as a control group. A strong correlation between the alteration of spermatogenesis and chromatin deterioration was observed in our study. In the same individuals, testicular samples showed a significantly lower DNA damage compared to ejaculated spermatozoa (14.9% ± 5.0 vs. 40.6% ± 14.8, P<0.05), but significantly higher aneuploidy rates for the five analyzed chromosomes (12.41% ± 3.7 vs. 5.77% ± 1.2, P<0.05). While testicular spermatozoa appear favourable for ICSI in terms of lower DNA damage, this potential advantage could be offset by the higher aneuploidy rates in testicular spermatozoa.

Development and current applications of assisted fertilization

Since the very early establishment of in vitro insemination, it became clear that one of the limiting steps is the achievement of fertilization. Among the different assisted fertilization methods, intracytoplasmic sperm injection emerged as the ultimate technique to allow fertilization with ejaculated, epididymal, and testicular spermatozoa. This work describes the early steps that brought forth the development of intracytoplasmic sperm injection and its role in assisted reproductive techniques. The current methods to select the preferential male gamete will be elucidated and the concerns related to the offspring of severe male factor couples will be discussed.

Chromosomal defects in infertile men with poor semen quality

PURPOSE

To assess the incidence and the type of chromosomal aberrations in males with infertility we reviewed cytogenetic results in 76 Tunisian infertile men (54 nonobstructive azoospermia and 22 oligo-asthenospermia).

METHODS

Karyotyping was performed on peripheral blood lymphocytes according to the standard methods. Molecular diagnosis of classical and partial Y-chromosomal microdeletions was performed by amplifying Y-specific STSs markers.

RESULTS

Various numerical and structural chromosome abnormalities were identified in 15 patients (19.48%). The occurrence of chromosomal abnormality in the azoospermics and severe oligo-asthnospermic was 21.7% and 13.5%, respectively. The most common was Klinefelter syndrome, accounting for 10 of the 15 cytogenetic defects. The total frequency of Y chromosomal microdeletions was 17.1%, with respective frequencies in azoospermic and severe oligospermic groups, 11.1% and 31.8%. The most frequent of Y chromosomal deletions were the partial ones (11.1% in azoospermic and 27.2% in oligospermic).

CONCLUSION

The occurrence of chromosomal abnormalities among infertile males strongly suggests the need for routine genetic testing and counseling prior to the employment of assisted reproduction techniques.

The use of fluorescent in situ hybridization in male infertility

Male factors are implicated in up to 50% of couples being evaluated and treated for infertility with advanced assisted reproductive technologies. Genetic abnormalities, including sperm chromosome aneuploidy as well as structural aberrations, are one of the major causes of infertility. The use of chromosome-specific DNA probes labeled with fluorochromes, particularly the combination with multiple probes, has been used to indirectly study the sperm chromosome by fluorescent in situ hybridization (FISH). Clinically, this technique is also used to assess the sperm of men recovering from gonadotoxic treatment. Recent advances in this technology facilitate the evaluation of sperm aneuploidy. Sperm FISH is a widely used screening tool to aid in counseling couples with severe male factor infertility, especially in cases of prior repeated in vitro fertilization/intracytoplasmic sperm injection failure or recurrent pregnancy loss. Automation of FISH imaging and analysis, as well as the development of emerging techniques such as comparative genomic hybridization, will all contribute to the promise of future diagnostic approaches aimed at improving the quality, ease, and efficiency of aneuploidy analysis.

Assessment of sperm chromatin condensation and ploidy status using flow cytometry correlates to fertilization, embryo quality and pregnancy following in vitro fertilization

PURPOSE

Sperm flow cytometry (SFC) was used to evaluate the association of sperm chromatin condensation and ploidy with fertilization, embryo development, pregnancy and abortion rates following IVF.

METHODS

Conventional semen analysis was performed in one hundred fifty men, as well as SFC analysis, after acridine orange and propidium iodide staining, for the evaluation of sperm maturity and ploidy respectively. Conventional IVF was performed in all couples.

RESULTS

Couples with low percentages of mature spermatozoa presented with lower fertilization rates (p < 0.005), lower rates of grade A embryos (p < 0.003) and lower pregnancy rates (p < 0.006), compared to couples with high percentages of mature spermatozoa. Couples with low total aneuploidy rates presented with higher fertilization rates (p < 0.007), higher rates of grade A embryos (p < 0.004) and higher pregnancy rates (p < 0.003), compared to couples with high total aneuploidy rates.

CONCLUSIONS

Sperm chromatin condensation and ploidy constitute critical parameters for the evaluation of semen samples before IVF and for the identification of cases in need of ICSI application.

Meiotic recombination and male infertility: from basic science to clinical reality?

Infertility is a common problem that affects approximately 15% of the population. Although many advances have been made in the treatment of infertility, the molecular and genetic causes of male infertility remain largely elusive. This review will present a summary of our current knowledge on the genetic origin of male infertility and the key events of male meiosis. It focuses on chromosome synapsis and meiotic recombination and the problems that arise when errors in these processes occur, specifically meiotic arrest and chromosome aneuploidy, the leading cause of pregnancy loss in humans. In addition, meiosis-specific candidate genes will be discussed, including a discussion on why we have been largely unsuccessful at identifying disease-causing mutations in infertile men. Finally clinical applications of sperm aneuploidy screening will be touched upon along with future prospective clinical tests to better characterize male infertility in a move towards personalized medicine.

What to do when ICSI fails

The refinement of gamete micromanipulation techniques has made conception possible for couples with male factor infertility who otherwise would remain childless. Moreover, intracytoplasmic sperm injection (ICSI) has ensured that such refractory cases can now generate offspring as successfully as in couples that merely require in vitro insemination. However, despite the now sterling record of ICSI it does not assure a successful outcome for every patient. This can be due, for instance, to the inability of the spermatozoon to activate the oocyte, and applies obviously in cases where spermatozoa are absent from the ejaculate or testicular biopsy. In the present paper we describe in detail the reasons for such failure and review the options that may help overcome it. In particular, we outline the treatment protocol for the situation in which spermatozoa are unable to induce oocyte activation. Further, we report on the clinical outcome achieved with spermatozoa retrieved from the testis, and in cases of extreme oligozoospermia we also explore the option of replicating a single spermatozoon while gaining information on its genomic content. For the most extreme situation in which men have no identifiable germ cells, we will discuss the current status of efforts to accomplish neo-gametogenesis through embryonic stem cell differentiation.

Meiotic recombination errors, the origin of sperm aneuploidy and clinical recommendations

Since the early 1990s male infertility has successfully been treated by intracytoplasmic sperm injection (ICSI), nevertheless concerns have been raised regarding the genetic risk of ICSI. Chromosome aneuploidy (the presence of extra or missing chromosomes) is the leading cause of pregnancy loss and mental retardation in humans. While the majority of chromosome aneuploidies are maternal in origin, the paternal contribution to aneuploidy is clinically relevant particularly for the sex chromosomes. Given that it is difficult to study female gametes investigations are predominantly conducted in male meiotic recombination and sperm aneuploidy. Research suggests that infertile men have increased levels of sperm aneuploidy and that this is likely due to increased errors in meiotic recombination and chromosome synapsis within these individuals. It is perhaps counterintuitive but there appears to be no selection against chromosomally aneuploid sperm at fertilization. In fact the frequency of aneuploidy in sperm appears to be mirrored in conceptions. Given this information this review will cover our current understanding of errors in meiotic recombination and chromosome synapsis and how these may contribute to increased sperm aneuploidy. Frequencies of sperm aneuploidy in infertile men and individuals with constitutional karyotypic abnormalities are reviewed, and based on these findings, indications for clinical testing of sperm aneuploidy are discussed. In addition, the application of single nucleotide arrays for the analysis of meiotic recombination and identification of parental origin of aneuploidy are considered.

[Non-obstructive azoospermia: option of the testicular sperm extraction performed on the day of oocyte retrieval]

OBJECTIVE

Analyzing the results and validating the procedure of testicular sperm extraction (TESE) performed on the day of oocyte retrieval in non obstructive azoospermia (NOA) patients.

PATIENTS AND METHODS

Sixty TESE were performed on the day of oocyte retrieval (dOR), in 52 NOA men. Patients were sorted into three groups according to the results of the surgical procedure: 1: sperm recovery with possible sperm freezing (n=20); 2: sperm recovery without freezing (n=27); 3: "negative" biopsy (n=13). ICSI outcomes in the two groups with sperm recovery were compared to those of ICSI performed with frozen-thawed sperm obtained from TESE performed (n=13).

RESULTS

The rate of positive sperm retrieval was 78%. While the overall clinical pregnancy rate was 50%, no difference in the fertilization, implantation and clinical pregnancy rates was found in the two groups with positive sperm retrieval as compared to frozen-thawed sperm group. Twelve pregnancies were obtained in patients without further sperm cryopreservation.

CONCLUSION

After TESE in NOA men, cryopreserved sperm produced comparable results with freshly obtained sperm. However, TESE performed on dOR can offer the opportunity, in patients with rare sperm that might not survive freeze-thaw, to have a possible fresh embryo transfer. Couples should be counselled regarding the possibility of oocyte retrieval without sperm for ICSI.

Quality assessment of induced spermatogenesis in hypogonadotrophic hypogonadic men treated with gonadotrophins

Hypogonadotrophic hypogonadism (HH) is characterized by deficient gonadotrophin secretion, resulting from pituitary or hypothalamic defects. In order to induce spermatogenesis, HH patients are treated with commercially available gonadotrophins. As far as is known, quality and genetic integrity of induced sperm cells have never been investigated, although they represent an important issue, since the ultimate goal of this treatment is to have competent spermatozoa in order to achieve paternity. In order to evaluate the nuclear integrity of induced sperm cells, sperm samples from treated HH patients were compared with sperm samples from normospermic control donors. Sperm cells were analysed by fluorescence in-situ hybridization, using probes specific for chromosomes 13, 21, 18, X and Y, and by TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling assay. Results showed that the rate of aneuploid and diploid sperm cells in patients was not statistically different from controls and that the rate of sperm cells with fragmented DNA was within the normal values. Spermatozoa obtained by gonadotrophin treatment in HH patients are likely to have a balanced chromosomal content and a normal DNA integrity but this conclusion needs to be confirmed by further studies dealing with a greater number of patients.

Testicular sperm from patients with obstructive and nonobstructive azoospermia: aneuploidy risk and reproductive prognosis using testicular sperm from fertile donors as control samples

OBJECTIVE

To establish a baseline incidence of chromosomal abnormalities in testicular sperm of fertile men and to determine the best control sample for comparisons with azoospermic males to estimate their reproductive prognosis.

DESIGN

Prospective study.

SETTING

Infertility clinic.

PATIENT(S)

Sixteen obstructive azoospermic (OA) and 19 nonobstructive azoospermic patients (NOA). Control samples were ejaculated sperm from ten fertile donors and testicular sperm from ten other fertile donors.

INTERVENTION(S)

Fluorescence in situ hybridization (FISH) in sperm.

MAIN OUTCOME MEASURE(S)

Sperm numerical abnormalities for chromosomes 13, 18, 21, X, and Y; ongoing implantation and pregnancy rates in intracytoplasmic sperm injection (ICSI) cycles.

RESULT(S)

In control samples, testicular sperm showed higher incidences of diploidy (0.27% vs. 0.10%) and disomy for chromosomes 13 (0.16% vs. 0.07%), 21 (0.25% vs. 0.12%), and sex chromosomes (0.34% vs. 0.21%) than ejaculated sperm. Comparisons with ejaculated control samples showed 12.5% OA and 68.4% NOA patients having significantly higher incidence of sperm chromosomal abnormalities. Compared with testicular control subjects, fewer OA (6.3%) and NOA (42.1%) patients had chromosomally abnormal sperm. NOA patients had lower ongoing implantation and pregnancy rates than OA patients, particularly those with abnormal FISH compared with testicular control samples.

CONCLUSION(S)

Sperm FISH analysis using testicular sperm control samples better identifies NOA patients with a lower likelihood of reproductive success.

Spermatogenesis affects the outcome of ICSI for azoospermic patients rather than sperm retrieval method

The study investigated the clinical outcome of intracytoplasmic sperm injection (ICSI) with epididymal and testicular sperm of azoospermic patients exhibiting various disturbances in spermatogenesis, in order to understand the possible factors that might affect ICSI outcome. Of the 134 patients, 92 were diagnosed as being obstructive azoospermic (OA group) with normal spermatogenesis and the remaining 42 patients were diagnosed as being non-obstructive azoospermic (NOA group) with hypospermatogenesis. The 92 OA patients underwent 112 ICSI cycles, which were divided into two subgroups according to their sperm retrieval methods: 1) OA-PESA group (n=51) with sperm obtained by percutaneous sperm aspiration (PESA) cycles and 2) OA-TEFNA group (n=61) with sperm obtained by testicular fine needle sperm aspiration (TEFNA) cycles. The NOA patients diagnosed with hypospermatogenesis according to histopathological analysis and hormone analysis, underwent 42 ICSI cycles with TEFNA. The results showed that the fertilization, cleavage, and clinical pregnancy rates portrayed a significant difference (44.9% vs. 64.1%, P<0.001, 79.8% vs. 89.0%, P<0.001, and 21.4% vs. 40.2%, P=0.047, respectively) between NOA and OA groups. Moreover, the miscarriage rate in the NOA group was visibly higher even though it did not reach a statistical difference (33.3% vs. 15.6%, P=0.433) compared with the miscarriage rate of the OA group. The same statistical differences were observed between the subgroup OA-TEFNA and the NOA group. No statistical difference was observed between OA-PESA and OA-TEFNA groups for the fertilization, cleavage, clinical pregnancy, and miscarriage rates. This study indicates that defective spermatogenesis affects the ICSI clinical outcome of azoospermic patients rather than the sperm retrieval methods.

Cytogenetic abnormalities detected in patients with non-obstructive azoospermia and severe oligozoospermia

PURPOSE

To find the frequency and types of major chromosomal abnormalities with nonobstructive azoospermia and severe oligozoospermia to give appropriate genetic counseling before assisted reproduction techniques in Isparta (South of Turkey), and to investigate the general characteristics in this infertile male population.

METHODS AND PATIENTS

A total of 115 infertile males (92 were azoospermic, 23 severe oligospermic) were studied for the cytogenetic evaluation prior to use of assisted reproduction techniques. Also, 60 fertile males as a control group were studied. Karyotyping was performed on peripheral blood lymphocytes according to the standard methods. Levels of luteinising hormone, follicle-stimulating hormone (FSH), testosterone and prolactin were obtained and a testicular sonography examination was conducted.

RESULTS

The total prevalence of chromosomal abnormalities was found to be 4.3% (5/115), including 4 patients with Klinefelter's Syndrome and 1 patient with gonadal dysgenesis (46XX). All of them were azoospermic males, corresponding to a frequency of 5.4% (5/92 patients). Oligozoospermic males and control males had no chromosomal abnormalities. There was a significant difference in serum FSH, LH, mean testicular volume and smoking when comparing patients (both azoospermic and oligozoospermic) and control groups (p<0.05). Also, there was a significant difference in serum FSH, LH and mean testicular volume when compared with azoospermic and oligozoospermic patients (p<0.05).

CONCLUSIONS

The occurrence of chromosomal abnormalities among infertile males strongly suggests the need for routine genetic testing and counseling prior to the employment of assisted reproduction techniques.

Clinical Review#: State of the art for genetic testing of infertile men

Intracytoplasmic sperm injection (ICSI) now provides fertility in many cases of severe idiopathic spermatogenic failure and obstructive azoospermia. Genetic causes must be sought by systematic evaluation of infertile men and affected couples informed about the implications of such diagnoses for assisted reproductive technology outcome and their potential offspring. This review discusses established and emerging genetic disorders related to fertility practice. Chromosomal anomalies are found in about 7% men with idiopathic spermatogenic failure, predominantly numerical/structural in azoospermic men and translocations/inversions in oligospermic men. Routine karyotyping of men with sperm densities less than 10 million/ml, even in the absence of other clinical presentations, is recommended because infertility is associated with higher rates of aneuploidy in ejaculated or testicular sperm and increased chromosomal defects in ICSI offspring. The long arm of the Y chromosome microdeletions are the most common recognized genetic cause of infertility and are found in about 4% men with sperm densities less than 5 million/ml. Routine testing using strict quality assurance procedures is recommended. Azoospermia factor (AZF)-c deletions, the most common form of the long arm of the Y chromosome microdeletions, are usually associated with low levels of sperm in the ejaculate or in testis biopsies, whereas men with AZFa or AZFb+c deletions usually produce no testicular sperm. When AZF-deleted sperm are available and used for ICSI, fertility defects in male offspring seem inevitable. Bilateral congenital absence of the vas is associated with heterozygosity for cystic fibrosis transmembrane receptor mutations making routine gene screening and genetic counseling of the couple essential. Testing for less common genetic associations/defects linked with different reproductive dysfunction may be applicable to specific patients but have not entered routine practice.

The genetic causes of male factor infertility: a review

OBJECTIVE

To illustrate the necessity for an enhanced understanding of the genetic basis of male factor infertility, to present a comprehensive synopsis of these genetic elements, and to review techniques being utilized to produce new insights in fertility research.

BACKGROUND

Male factor infertility is a complex disorder that affects a large sector of the population; however, many of its etiologies are unknown. By elucidating the underlying genetic basis of infertile phenotypes, it may be possible to discover the causes of infertility and determine effective treatments for patients.

METHOD(S)

The PubMed database was consulted for the most relevant papers published in the last 3 years pertaining to male factor infertility using the keywords "genetics" and "male infertility."

RESULT(S)

Advances have been made in the characterization of the roles of specific genes, but further research is necessary before these results can be used as guidelines for diagnosing and treating male factor infertility. The accurate transmission of epigenetic information also has considerable influence on fertility in males and on the fertility of their offspring.

CONCLUSION(S)

Analysis of the genetic factors that impact male factor infertility will provide valuable insights into the creation of targeted treatments for patients and the determination of the causes of idiopathic infertility. Novel technologies that analyze the influence of genetics from a global perspective may lead to further developments in the understanding of the etiology of male factor infertility through the identification of specific infertile phenotype signatures.

Should non-mosaic Klinefelter syndrome men be labelled as infertile in 2009?

BACKGROUND

Klinefelter syndrome is a common genetic condition. Affected non-mosaic men are azoospermic and have been labelled as infertile. Despite reports that these men can have children using assisted reproduction techniques, it is not common practice in the UK to offer sperm retrieval to these men.

METHODS

Medline and EMBASE (1980-2009) were searched independently by two authors and all studies involving surgical sperm retrieval in non-mosaic Klinefelter syndrome were included. The primary outcome was success of surgical sperm retrieval and the secondary outcome was live birth rate.

RESULTS

The overall success rate for sperm retrieval was 44%, with a higher rate of success using micro-dissection testicular sperm aspiration (micro-TESE) (55%). This, along with ICSI, has led to the birth of 101 children. However, there are no known predictors for successful sperm retrieval. Although there are concerns about genetic risk to the offspring of non-mosaic Klinefelter patients, this risk has not been found to be greater than that of patients with non-obstructive azoospermia with normal karyotype.

CONCLUSIONS

It is possible for a man with non-mosaic Klinefelter to father a child. However, before these techniques are offered, some ethical issues need to be explored.