Follicle-stimulating hormone as a predictor for sperm retrieval rate in patients with nonobstructive azoospermia: a systematic review and meta-analysis

Overview of infertility

Having a child is an innate trait in animals, including humans, and is required for the continued existence of all animal species. Therefore, for most women, the inability to conceive or to do so in a timely fashion - termed infertility - to enable the continuation of the family line can be emotionally distressing. The definition of infertility is controversial because of its separation into primary and secondary. This is further complicated by the loosely used term subfertility, which relates to couples who have reduced ability because they take longer than the natural time to conceive, as opposed to those who are infertile and are entirely unable to conceive after 6 to 12 months, depending on age. Infertility evaluation requires a thorough male and female history, physical examination of both partners, and targeted investigation to determine the cause of infertility in a particular couple. Various treatments apply to infertile couples depending on the age of the female partner, the results of investigations, the reason for infertility, the presence of inheritance of abnormal genes, the pregnancy rates the couple is happy with, the resources available, how desperate the couple is to achieve a live birth, and how much they want to commit to treatment. Infertility treatment could include counseling and expectant management only, intrauterine insemination in a natural or stimulated cycle, and IVF and or ICSI. Men with azoospermia will need surgical options to retrieve sperm for IVF/ ICSI, but rarely for IUI. This review overviews infertility's etiology, diagnosis, investigations, and treatment.

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2025 Update on Male Infertility

BACKGROUND AND OBJECTIVE

To present a summary of the updated 2025 European Association of Urology (EAU) Guidelines on Sexual and Reproductive Health (SRH) on male infertility, providing practical recommendations on the clinical work-up with a focus on diagnosis, treatment and follow-up.

METHODS

For the 2025 SRH guidelines, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of a thorough urological assessment of all men seeking medical help for fertility problems to ensure appropriate treatment. The guidelines also stress the clinical relevance of a parallel investigation of the female partner during the diagnostic and management work-up of the infertile couple, to promote shared-decision making in terms of timing and therapeutic strategies. Furthermore, the guidelines recommend to counsel all infertile men and men with abnormal semen parameters on the associated health risks. Key changes in the male infertility guidelines for 2025 include: the addition of two new sections addressing exome sequencing and probiotic treatment; and significant update of the evidence base and recommendations for the diagnostic work-up of male infertility.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2025 SHR guidelines offers valuable insights into the diagnosis, classification, treatment and follow-up of male factor infertility and are designed for effective integration into clinical practice.

A Nomogram Predicting Testicular Sperm Extraction Success in Men With Non-obstructive Azoospermia: A Multi-center Study

OBJECTIVE

To develop an efficient and easy-to-use nomogram that can predict testicular sperm extraction (TESE) success in men with non-obstructive azoospermia (NOA) by using pre-operative parameters.

MATERIALS AND METHODS

Data of 3093 men who underwent TESE for NOA were included in this study. Demographic data, testis volumes, presence of varicocele, length of infertility, history of previous surgeries, history of genitourinary infections, smoking status, chromosome abnormalities, presence of Y-chromosome microdeletion, family history of infertility, testis biopsy, surgical data, sperm retrieval rate, final pathology obtained at TESE, follicle-stimulating hormone, luteinizing hormone, and testosterone levels were recorded. The primary outcome was to develop an efficient nomogram that can predict the TESE success in men with NOA. The secondary outcomes were identifying the significant pre-operative parameters that are associated with success in TESE.

RESULTS

Sperm retrieval rate was 50.2%(1553/3093). Testis volume, history of varicocelectomy, chromosome abnormalities, and presence of Y-chromosome microdeletion were shown to affect sperm retrieval rate significantly (P <.05). Sperm retrieval success was higher in men with older age, higher testis volume (>10 mL), lower follicle-stimulating hormone level (≤12.92 mIU/mL), lower luteinizing hormone level, and higher testosterone level (P <.05). Only testis volume and patient's age were associated with successful sperm retrieval in multivariate logistic regression analysis.

CONCLUSION

In men with NOA, high testis volume, old age, low follicle-stimulating hormone level, low luteinizing hormone level, and high testosterone level are advantageous for successful sperm retrieval in TESE. Herein, we present a nomogram that can predict the outcome of TESE in men with NOA with adequate success.

Testicular histopathology and follicular stimulating hormone to predict fertility in nonobstructive azoospermia

PURPOSE

To examine the ability of testicular histopathology in Non-obstructive azoospermia (NOA) in predicting sperm retrieval rate (SR), sperm quality and assisted reproductive technology success.

METHODS

A retrospective study recruited clinically diagnosed NOA patients between 2007 and 2015. Testicular biopsy and conventional sperm extraction (TESE) were done concomitantly. Correlation between pathological categories, SR rate, sperm quality and success of intracytoplasmic sperm injection (ICSI) was studied. FSH was measured as a predictor of fertility.

RESULTS

One hundred eighteen patients were recruited. Histopathological classification was hypospermatogenesis (HS) 45 (38%), maturation arrest (MA) 22(19%), Sertoli cell only syndrome (SCOS) 34 (29%) and normal spermatogenesis (NS) 17 (14%). FSH value was above normal level in 34 (76%) of HS, 19 (86%) of MA, 32 (94%) of SCOS and 5 (29%) of NS. Positive SR was obtained in 108 (92%) patients. The highest SR rate was seen in NS group 100% and the lowest was in SCOS 26 (77%). The worst sperm quality was found in SCOS as type C represents 46%, followed by MA 40% and HS 24%. Patients had ICSI following TESE had variable success rate as success of ICSI was seen (9/15) for HS, (0/7) for MA, (5/15) for SCOS and (8/9) for NS. FSH is strongly correlated to SR, quality of sperm and success of ICSI as positive SR in normal FSH patients was obtained in 28 (100%) of normal FSH, 70 (97%) of high FSH and 10 (56%) of double high FSH (p value < 001). The success of ICSI significantly correlates with FSH value as normal FSH has 77% success ICSI rate, high FSH (52%) and double high FSH (0%) (p value < 0.001).

CONCLUSIONS

Testicular biopsy and histopathology findings in NOA are strongly correlated SR rate, quality of sperms, and success of ICSI. FSH is a strong noninvasive predictor of fertility in NOA patients.

Clinical factors impacting microdissection testicular sperm extraction success in hypogonadal men with nonobstructive azoospermia

OBJECTIVE

To explore factors influencing microdissection testicular sperm extraction (micro-TESE) success in hypogonadal men with nonobstructive azoospermia (NOA).

DESIGN

A cohort study.

SETTING

University-affiliated male reproductive health center.

PATIENT(S)

A total of 616 consecutive patients with NOA and hypogonadism (total testosterone [T] levels <350 ng/dL) underwent micro-TESE between 2014 and 2021. All patients had no prior sperm retrieval (SR) history.

INTERVENTION(S)

Patients aged 23-55 years underwent comprehensive clinical, laboratory, and histopathological diagnostic evaluation for NOA and were further categorized into two cohorts on the basis of pre-SR hormonal stimulation.

MAIN OUTCOME MEASURE(S)

A multivariable logistic regression analysis explored the associations between patient variables and micro-TESE success, defined as the presence of viable spermatozoa in extracted specimens. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were computed to assess the relationship between SR success and relevant predictors. Sperm retrieval rates were compared between patients receiving or not hormonal stimulation, and logistic regression analysis evaluated the effect of baseline follicle-stimulating hormone levels (i.e., normogonadotropic vs. hypergonadotropic classes) on SR success.

RESULT(S)

The overall micro-TESE success rate was 56.6%. Baseline follicle-stimulating hormone levels (aOR, 0.97; 95% CI, 0.94-0.99), pre-SR hormonal stimulation (aOR, 2.54; 95% CI, 1.64-3.93), presence of clinical varicocele (aOR, 0.05; 95% CI, 0.01-0.51), history of previous varicocelectomy (aOR, 2.55; 95% CI, 1.26-5.16), and testicular histopathology were independent predictors of SR success. Among hormone-pretreated patients, pre-micro-TESE T levels and delta T (an absolute increase in T levels from baseline) were associated with SR success. A pre-micro-TESE T level of 418.5 ng/dL (area under the curve value: 0.78) and a delta T of 258 ng/dL (area under the value: 0.76) distinguished patients with positive and negative SR outcomes. Subgroup analysis showed that pre-SR hormonal stimulation yielded a greater benefit for normogonadotropic patients than for those who were hypergonadotropic.

CONCLUSION(S)

This study underscores the association between clinical factors and micro-TESE success in hypogonadal men with NOA. Although causality is not established, our findings suggest that these patients may benefit from pre-SR interventions, particularly hormonal stimulation and varicocele repair.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05110391.

Clinical management of nonobstructive azoospermia: An update

Approximately 1% of the general male population has azoospermia, and nonobstructive azoospermia accounts for the majority of cases. The causes vary widely, including chromosomal and genetic abnormalities, varicocele, drug-induced causes, and gonadotropin deficiency; however, the cause is often unknown. In azoospermia caused by hypogonadotropic hypogonadism, gonadotropin replacement therapy can be expected to produce sperm in the ejaculate. In some cases, upfront varicocelectomy for nonobstructive azoospermia with varicocele may result in the appearance of ejaculated spermatozoa; however, the appropriate indication should be selected. Each guideline recommends microdissection testicular sperm extraction for nonobstructive azoospermia in terms of successful sperm retrieval and avoidance of complications. Sperm retrieval rates generally ranged from 20% to 70% but vary depending on the causative disease. Various attempts have been made to predict sperm retrieval and improve sperm retrieval rates; however, the evidence is insufficient. Further evidence accumulation is needed for salvage treatment in cases of failed sperm retrieval. In Japan, there is inadequate provision on the right to know the origin of children born from artificial insemination of donated sperm and the rights of sperm donors, as well as information on unrelated family members, and the development of these systems is challenging. In the future, it is hoped that the pathogenesis of nonobstructive azoospermia with an unknown cause will be elucidated and that technology for omics technologies, human spermatogenesis using pluripotent cells, and organ culture methods will be developed.

Clinical parameters as predictors for sperm retrieval success in azoospermia: experience from Indonesia

Background

Azoospermia is the most severe type of male infertility. This study aimed to identify useful clinical parameters to predict sperm retrieval success. This could assist clinicians in accurately diagnosing and treating patients based on the individual clinical parameters of patients.

Methods

A retrospective cohort study was performed involving 517 patients with azoospermia who underwent sperm retrieval in Jakarta, Indonesia, between January 2010 and April 2023. Clinical evaluation and scrotal ultrasound, serum follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels were evaluated before surgery. Multivariate analyses were conducted to determine clinical parameters that could predict overall sperm retrieval success. Further subgroup analysis was performed to determine the factors that the diagnosis of non-obstructive azoospermia (NOA) diagnosis and sperm retrieval success among patients with NOA.

Results

A total of 2,987 infertile men attended our clinic. Men with azoospermia (n=517) who met the inclusion criteria and did not fulfil any exclusion criteria were included in the study. The overall sperm retrieval success was 47.58%. Logistic regression revealed that FSH 7.76 mIU/mL (sensitivity: 60.1%, specificity: 63.3%, p<0.001); longest testicular axis length 3.89 cm (sensitivity: 33.6%, specificity: 41.6%); and varicocele (p<0.001) were independent factors for overall sperm retrieval. The FSH cutoff of 7.45 mIU/mL (sensitivity: 31.3%, specificity: 37.7%, p<0,001); longest testicular axis length 3.85 cm (sensitivity: 76.7%, specificity: 65.4%, p<0.001); and varicocele (p<0.001) were independent factors for NOA diagnosis. Varicocele was the only clinical parameter that significantly predicted the success of sperm retrieval in patients with NOA.

Conclusions

FSH, LH, longest testicular axis, and varicocele are among the clinical parameters that are useful for predicting overall sperm retrieval success and NOA diagnosis. However, varicocele is the only clinical parameter that significantly predicts sperm retrieval success in patients with NOA. High-quality studies are required to assess the other predictors of sperm retrieval success.

Enzymatic tissue processing after testicular biopsy in non-obstructive azoospermia enhances sperm retrieval

STUDY QUESTION

What is the added value of enzymatic processing of testicular biopsies on testicular sperm retrieval (SR) rates for patients with non-obstructive azoospermia (NOA)?

SUMMARY ANSWER

In addition to mechanical mincing, enzymatic digestion increased SR rates in testicular biopsies of NOA patients.

WHAT IS KNOWN ALREADY

Many studies focus on the surgical approach to optimize recovery of testicular sperm in NOA, and in spite of that, controversy still exists about whether the type of surgery makes any difference as long as multiple biopsies are taken. Few studies, however, focus on the role of the IVF laboratory and the benefit of additional lab procedures, e.g. enzymatic digestion, in order to optimize SR rates.

STUDY DESIGN SIZE DURATION

This retrospective single-center cohort study included all patients who underwent their first testicular sperm extraction (TESE) by open multiple-biopsy method between January 2004 and July 2022. Only patients with a normal karyotype, absence of Y-q deletions and a diagnosis of NOA based on histology were included. The primary outcome was SR rate after mincing and/or enzymes. The secondary outcome was cumulative live birth (CLB) after ICSI with fresh TESE and subsequent ICSI cycles with frozen TESE.

PARTICIPANTS/MATERIALS SETTING METHODS

Multiple biopsies were obtained from the testis, unilaterally or bilaterally, on the day of oocyte retrieval. Upon mechanical mincing, biopsies were investigated for 30 min; when no or insufficient numbers of spermatozoa were observed, enzymatic treatment was performed using Collagenase type IV. Multivariable regression analysis was performed to predict CLB per TESE by adjusting for the following confounding factors: male FSH level, female age, and requirement of enzymatic digestion to find sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 118 patients, of whom 72 (61.0%) had successful SR eventually. Spermatozoa were retrieved after mechanical mincing for 28 patients (23.7%; 28/118) or after additional enzymatic digestion for another 44 patients (37.2%; 44/118). Thus, of the 90 patients requiring enzymatic digestion, sperm were retrieved for 44 (48.9%). Male characteristics were not different between patients with SR after mincing or enzymatic digestion, in regard to mean age (34.5 vs 34.5 years), testis volume (10.2 vs 10.6 ml), FSH (17.8 vs 16.9 IU/l), cryptorchidism (21.4 vs 34.1%), varicocele (3.6 vs 4.6%), or histological diagnosis (Sertoli-cell only 53.6 vs 47.7%, maturation arrest 21.4 vs 38.6%, sclerosis/atrophy 25.0 vs 13.6%).Of the 72 patients with sperm available for ICSI, 23/72 (31.9%) achieved a live birth (LB) after the injection with fresh testicular sperm (and fresh or frozen embryo transfers). Of the remaining 49 patients without LB, 34 (69.4%) had supernumerary testicular sperm frozen. Of these 34 patients, 19 (55.9%) continued ICSI with frozen testicular sperm, and 9/19 (47.4%) had achieved an LB after ICSI with frozen testicular sperm. Thus, the total CLB was 32/118 (27.1%) per TESE or 32/72 (44.4%) per TESE with sperm retrieved.Of the female characteristics (couples with sperm available), only female age (30.3 vs 32.7 years; P = 0.042) was significantly lower in the group with a LB, compared to those without.The CLB with testicular sperm obtained after enzymatic digestion was 31.8% (14/44), while the CLB with sperm obtained after mincing alone was 64.3% (18/28). Multivariable logistic regression analysis showed that when enzymatic digestion was required, it was associated with a significant decrease in CLB per TESE (OR: 0.23 (0.08-0.7); P = 0.01).

LIMITATIONS REASONS FOR CAUTION

Limitations of the study are related to the retrospective design. However, the selection of only patients with NOA, and specific characteristics (normal karyotype and absence Y-q deletion) and having their first TESE, strengthens our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Enzymatic processing increases the SR rate from testicular biopsies of NOA patients compared to mechanical mincing only, demonstrating the importance of an appropriate laboratory protocol. However, NOA patients should be counseled that when sperm have been found after enzymatic digestion, their chances to father a genetically own child may be lower compared to those not requiring enzymatic digestion.

STUDY FUNDING/COMPETING INTERESTS

None reported.

TRIAL REGISTRATION NUMBER

N/A.

Varicocele: An Endocrinological Perspective

Varicocele affects 15% of male population but it is more frequently identified in patients searching medical care for infertility. The impact of varicocele on semen production and fertility is known, but the relationship between clinical varicocele and impaired hormonal production is not clear. In published literature there are some studies regarding hormonal alterations in patients with varicocele but no review in which all the hormonal findings are explained. The aim of this review is to evaluate, by most common search engine, what is known about hormonal alterations in varicocele-bearing patients, to verify if a cause-effect relationship is documented and to give a useful contribution to in clinical management of this kind of patients. We found contradictory results about hormonal status from literature. Some studies confirmed a decrease of testosterone levels and higher FSH and LH levels that normalize after varicocelectomy, others found lower than normal levels of dihydrotestosterone due to decreased activity of epididymal 5-α-reductase. Lower circulating Anti-Müllerian Hormone levels, accompanied by a decreased Inhibin-B level, were reported as indicators of the decreased Sertoli cells function in varicocele-bearing adult patients. The finding of higher basal 17-OH-progesterone concentrations in patients with varicocele was explained by some authors with a testicular C-17,20-lyase deficiency. There is no doubt that varicocele could led to hormonal alterations. This review proposes that the impaired free sexual steroid levels are the result of a slight, deep-rooted defect in the testes of a certain amount of men with varicocele but further multicentre, randomized controlled studies remain mandatory to better clarify the hormonal features of patients with varicocele and to assess the utility of hormonal evaluation for establishing the duration of varicocele and for better identifying patients who need surgical correction.

Systemic immune-inflammation index, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio are predictors of sperm presence in microdissection testicular sperm extraction

The aim of this study is to evaluate the value of the haematologic inflammatory parameters in predicting sperm retrieval rates during microdissection testicular sperm extraction (micro-TESE).159 patients diagnosed with non-obstructive azoospermia were included in the study. After excluding the patients that do not fit the inclusion criteria, age, smoking status, body-mass index, serum luteinizing hormone, follicle-stimulating hormone, total testosterone levels and neutrophil, lymphocyte and platelet counts were recorded. Neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and systemic immune-inflammation index were calculated. The primary outcome was defined as the presence of spermatozoa during the procedure and the association between the candidate predictors and primary endpoint were evaluated by logistic regression analysis. Then, a baseline model from age, smoking, body-mass index and hormonal levels was built. Ratios and indexes were included, respectively, and were compared by multivariate analyses. Each of all three parameters was an independent predictor of obtaining spermatozoa during micro-TESE procedure (all p < 0.001). Even though all three parameters were significant, neutrophil-lymphocyte ratio and systemic immune-inflammation index stood out as more powerful than platelet-lymphocyte ratio (p < 0.08, p < 0.08 respectively). Additionally, adding these parameters individually to the baseline model significantly empowered the predictive value (all p < 0.001). Using haematologic inflammatory parameters in the prediction of sperm presence during microdissection testicular sperm extraction may be helpful when consulting the patient with having a better foresight of the procedural outcomes.

Assessment of hormonal status in male infertility. An update

BACKGROUND AND AIMS

The prevalence and incidence of infertility are increasing worldwide; they are associated with a significant economic and social impact. Infertility is defined as the inability to achieve pregnancy after 12 months or more of regular unprotected sex. In recent times, the male factor has gained importance and currently it contributes to approximately 50% of infertility cases. Multiple etiologies are stated, such as metabolic, anatomical, genetic or even idiopathic causes; however, the main cause is semen abnormalities. The aim of this manuscript is to provide a complete review of hormonal assessment of male infertility, as well as to review the physiology and pathophysiology related to the male gonadal axis.

METHODS

This study is a narrative abstract carried out on basis of systematic bibliographic review, using articles indexed in PubMed/Medline, Scopus, Embase and Scielo, which were published during the last 20 years.

RESULTS

The cornerstone of the evaluation of the hormonal status is semen analysis. Clinicians must rule out hypogonadism in those patients who present oligospermia and azoospermia, by determining levels of testosterone and gonadotropins, which provide the functionality status of the hypothalamic-pituitary-testicular axis. Evaluation of the adrenal, thyroid, and lactotroph axis are indicated in those patients with central hypogonadism.

CONCLUSIONS

Despite advances in the diagnosis of male infertility, some causes are not fully understood, therefore, it is crucial to perform a timely hormonal evaluation of the male factor in infertile couples, in order to provide adequate treatment and improve fertility rates.

Azoospermic men with isolated elevation of follicle-stimulating hormone represent a specific subpopulation of patients with poor reproductive outcomes

Objective

This study aimed to describe a distinct subpopulation of azoospermic patients with isolated elevation of follicle-stimulating hormone (iFSH) and poor outcomes of microdissection testicular sperm extraction (microTESE).

Methods

A retrospective analysis of microTESE outcomes was conducted among 565 patients with non-obstructive azoospermia (NOA). Testicular pathology was assessed by the dominant histological pattern and Bergmann-Kliesch score (BKS). Descriptive statistics were presented for the iFSH subgroup. Inhibin B levels, the sperm retrieval rate (SRR), and BKS were compared in iFSH patients and other NOA patients.

Results

The overall SRR was 33.3% per microTESE attempt. The median BKS was 0.6 (interquartile range, 0–2). Of all NOA patients, 132 had iFSH, and microTESE was successful only in 11 of those cases, with an SRR of 8.3%, while the total SRR in other NOA patients was 38.1% (p<0.001). iFSH had a sensitivity of 32.1% (95% confidence interval [CI], 27.4%–36.8%) and specificity of 94.1% (95% CI, 90.8–97.5%) as a predictor of negative microTESE outcomes.

Conclusion

Patients with iFSH may harbor a distinct testicular phenotype with total loss of the germ cell population and poor outcomes of surgical sperm retrieval.

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2021 Update on Male Infertility

CONTEXT

The European Association of Urology (EAU) has updated its guidelines on sexual and reproductive health for 2021.

OBJECTIVE

To present a summary of the 2021 version of the EAU guidelines on sexual and reproductive health, including advances and areas of controversy in male infertility.

EVIDENCE ACQUISITION

The panel performed a comprehensive literature review of novel data up to January 2021. The guidelines were updated and a strength rating for each recommendation was included that was based either on a systematic review of the literature or consensus opinion from the expert panel, where applicable.

EVIDENCE SYNTHESIS

The male partner in infertile couples should undergo a comprehensive urological assessment to identify and treat any modifiable risk factors causing fertility impairment. Infertile men are at a higher risk of harbouring and developing other diseases including malignancy and cardiovascular disease and should be screened for potential modifiable risk factors, such as hypogonadism. Sperm DNA fragmentation testing has emerged as a novel biomarker that can identify infertile men and provide information on the outcomes from assisted reproductive techniques. The role of hormone stimulation therapy in hypergonadotropic hypogonadal or eugonadal patients is controversial and is not recommended outside of clinical trials. Furthermore, there is insufficient evidence to support the widespread use of other empirical treatments and surgical interventions in clinical practice (such as antioxidants and surgical sperm retrieval in men without azoospermia). There is low-quality evidence to support the routine use of testicular fine-needle mapping as an alternative diagnostic and predictive tool before testicular sperm extraction (TESE) in men with nonobstructive azoospermia (NOA), and either conventional or microdissection TESE remains the surgical modality of choice for men with NOA.

CONCLUSIONS

All infertile men should undergo a comprehensive urological assessment to identify and treat any modifiable risk factors. Increasing data indicate that infertile men are at higher risk of cardiovascular mortality and of developing cancers and should be screened and counselled accordingly. There is low-quality evidence supporting the use of empirical treatments and interventions currently used in clinical practice; the efficacy of these therapies needs to be validated in large-scale randomised controlled trials.

PATIENT SUMMARY

Approximately 50% of infertility will be due to problems with the male partner. Therefore, all infertile men should be assessed by a specialist with the expertise to not only help optimise their fertility but also because they are at higher risk of developing cardiovascular disease and cancer long term and therefore require appropriate counselling and management. There are many treatments and interventions for male infertility that have not been validated in high-quality studies and caution should be applied to their use in routine clinical practice.

Immunohistochemical examination of androgen receptor and estrogen receptor alpha expressions in obstructive and non-obstructive azoospermia

In this study, the expression of the androgen receptor (AR) and estrogen receptor alpha (ERα) in testicular tissue of male patients with obstructive azoospermia (OA) and non-obstructive azoospermia (NOA) were evaluated by immunohistochemistry. NOA (n = 23) and OA (n = 21) groups were created according to clinical and laboratory archival records. Testicular sperm extraction tissue sections were evaluated according to Johnsen's tubular biopsy scoring (JTBS) method. ERα and AR immunostaining results were evaluated semiquantitatively. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and estradiol were analyzed. Serum FSH and LH concentrations were greater, and testosterone concentrations were lower than the normal values in the NOA group, whereas the OA group revealed normal hormonal values. Serum estradiol concentrations in groups were in the normal range. JTBSs were significantly lower in the NOA group. Decreased AR expression and increased ERα expression were observed in the NOA group compared to the OA group. This suggests that ERα and AR are expressed in Sertoli cells, Leydig cells, and myoid cells and are required for normal testicular function. Decreased expression of the AR and increased expression of ERα in the testis may negatively affect spermatogenesis.Abbreviations: AR: androgen receptor; ER: estrogen receptor; ERα: estrogen receptor alpha; FSH: follicle-stimulating hormone; JTBS: Johnsen's tubular biopsy scoring; LH: luteinizing hormone; NOA: non-obstructive azoospermia; OA: obstructive azoospermia; TESE: testicular sperm extraction.

A panel of extracellular vesicle long noncoding RNAs in seminal plasma for predicting testicular spermatozoa in nonobstructive azoospermia patients

STUDY QUESTION

Whether the testis-specific extracellular vesicle (EV) long noncoding RNAs (lncRNAs) in seminal plasma could be utilized to predict the presence of testicular spermatozoa in nonobstructive azoospermia (NOA) patients?

SUMMARY ANSWER

Our findings indicate that the panel based on seminal plasma EV lncRNAs was a sensitive and specific method in predicting the presence of testicular spermatozoa and may improve clinical decision-making of NOA.

WHAT IS KNOWN ALREADY

The adoption of sperm retrieval techniques, especially microdissection testicular sperm extraction (mTESE), in combination with ICSI has revolutionized treatment for NOA. However, there are no precise and noninvasive methods for predicting whether there are testicular spermatozoa in NOA patients before mTESE.

STUDY DESIGN, SIZE, DURATION

RNA sequencing was performed on seminal plasma EVs from 6 normozoospermic men who underwent IVF due to female factor and 5 idiopathic NOA patients who failed to obtain testicular spermatozoa by mTESE and were diagnosed as having Sertoli cell-only syndrome by postoperative pathology. A biomarker panel of lncRNAs was constructed and verified in 96 NOA patients who underwent mTESE. Decision-making process was established based on the panel in seminal plasma EVs from 45 normozoospermia samples, 43 oligozoospermia samples, 62 cryptozoospermia samples, 96 NOA samples.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RNA sequencing was done to examine altered profiles of EV lncRNAs in seminal plasma. Furthermore, a panel consisting of EV lncRNAs was established and evaluated in training set and validation sets.

MAIN RESULTS AND THE ROLE OF CHANCE

A panel consisting of nine differentially expressed testis-specific lncRNAs, including LOC100505685, SPATA42, CCDC37-DT, GABRG3-AS1, LOC440934, LOC101929088 (XR_927561.2), LOC101929088 (XR_001745218.1), LINC00343 and LINC00301, was established in the training set and the AUC was 0.986. Furthermore, the AUC in the validation set was 0.960. Importantly, the panel had a unique advantage when compared with models based on serum hormones from the same group of NOA cases (AUC, 0.970 vs 0.723; 0.959 vs 0.687, respectively). According to the panel of lncRNAs, a decision-making process was established, that is when the score of an NOA case exceeds 0.532, sperm retrieval surgery may be recommended.

LIMITATIONS, REASONS FOR CAUTION

In the future, the sample size needs to be further expanded. Meanwhile, the regulatory functions and mechanism of lncRNAs in spermatogenesis also need to be elucidated.

WIDER IMPLICATIONS OF THE FINDINGS

When the score of our panel is below 0.532, subjecting the NOA patients to ineffective surgical interventions may not be recommended due to poor sperm retrieval rate.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China (81871110, 81971314 and 81971759); the Guangdong Special Support Plan-Science and Technology Innovation Youth Top Talents Project (2016TQ03R444); the Science and Technology Planning Project of Guangdong Province (2016B030230001 and 201707010394); the Key Scientific and Technological Program of Guangzhou City (201604020189); the Pearl River S&T Nova Program of Guangzhou (201806010089); the Transformation of Scientific and Technological Achievements Project of Sun Yat-sen University (80000-18843235) and the Youth Teacher Training Project of Sun Yat-sen University (17ykpy68 and 18ykpy09). There are no competing interests related to this study.

TRIAL REGISTRATION NUMBER

N/A.

Two Decades from the Introduction of Microdissection Testicular Sperm Extraction: How This Surgical Technique Has Improved the Management of NOA

The treatment of men with non-obstructive azoospermia (NOA) has improved greatly over the past two decades. This is in part due to the discovery of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), but also significantly due to improvements in surgical sperm retrieval methods, namely the development of microdissection testicular sperm extraction (mTESE). This procedure has revolutionized the field by allowing for identification of favorable seminiferous tubules while simultaneously limiting the amount of testicular tissue removed. Improving sperm retrieval rates is imperative in this cohort of infertile men as there are a limited number of factors that are predictive of successful sperm retrieval. Currently, sperm retrieval in NOA men remains dependent on surgeon experience, preoperative patient optimization and teamwork with laboratory personnel. In this review, we discuss the evolution of surgical sperm retrieval methods, review predictors of sperm retrieval success, compare and contrast the data of conventional versus mTESE, share tips for optimizing sperm retrieval outcomes, and discuss the future of sperm retrieval in men with NOA.

Outcome prediction of microdissection testicular sperm extraction based on extracellular vesicles piRNAs

PURPOSE

Microdissection testicular sperm extraction (micro-TESE) could retrieve sperm from the testicles to help the non-obstructive azoospermia (NOA) patients to get their biological children, but also would cause damage to the testicles. Therefore, it is necessary to preoperatively predict the micro-TESE outcome in NOA patients. For this purpose, we aim to develop a model based on extracellular vesicles' (EVs) piRNAs (EV-piRNAs) in seminal plasma.

METHODS

To identify EV-piRNAs that were associated with spermatogenic ability, small RNA-seq was performed between the NOA group (n = 8) and normal group (n = 8). Validation of EV-piRNA expression in seminal plasma EVs and testicles tissues was used to select EV-piRNAs for the model. Candidate EV-piRNAs were further selected by LASSO regression analysis. Binary logistic regression analysis was used for the models' calculation formula. ROC analysis and Hosmer-Lemeshow test was used to assess the models' performance in the training (n = 20) and validation (n = 25) cohorts.

RESULTS

We identified 8 EV-piRNAs which were associated with spermatogenic ability. Two EV-piRNAs (pir-60351 and pir-61927) were selected by LASSO regression analysis. Finally, we developed a favorable model based on the expression of pir-61927 with good discrimination wherein the AUC was 0.82 (95% CI: 0.63~1.00, p = 0.016) in the training cohort and 0.83 (95% CI: 0.66~1.00, p = 0.005) in the validation cohort, as well as good calibration.

CONCLUSIONS

A favorable model based on the expression of pir-61927 in seminal plasma EVs was established to predict the micro-TESE outcome in NOA patients.

Non-obstructive azoospermia: current and future perspectives

Infertility affects 1 in 6 couples, and male factor infertility has been implicated as a cause in 50% of cases. Azoospermia is defined as the absence of spermatozoa in the ejaculate and is considered the most extreme form of male factor infertility. Historically, these men were considered sterile but, with the advent of testicular sperm extraction and assisted reproductive technologies, men with azoospermia are able to biologically father their own children. Non-obstructive azoospermia (NOA) occurs when there is an impairment to spermatogenesis. This review describes the contemporary management of NOA and discusses the role of hormone stimulation therapy, surgical and embryological factors, and novel technologies such as proteomics, genomics, and artificial intelligence systems in the diagnosis and treatment of men with NOA. Moreover, we highlight that men with NOA represent a vulnerable population with an increased risk of developing cancer and cardiovascular comorbodities.

Can preoperative parameters predict successful sperm retrieval and live birth in couples undergoing testicular sperm extraction and intracytoplasmic sperm injection for azoospermia?

Background

We aimed to determine if the success of TESE and live-birth following TESE-ICSI can be predicted from readily available preoperative parameters for couples with azoospermia. Our methodology was as follows, this was a cohort study of couples who attended the fertility service (from 2009-2019) at an NHS hospital in whom the male partner was diagnosed with azoospermia and required conventional TESE with multiple biopsies to obtain sperm. Of 414 men included, 223 had successful TESE and of those 178 have used sperm in ICSI cycle(s). Predictive models were developed using logistic regression. We assessed model performance by internally validated concordance statistics and calibration plots. Successful sperm retrieval was defined as the presence of motile sperm which survived the freeze-thaw process and live-birth defined as delivery after 34 weeks of gestation.

Results

Successful TESE was associated with higher male age and lower FSH. The TESE model discriminated well with a c statistic of 0.81 (0.77-0.85). Live-birth was associated with lower maternal age, earlier ICSI cycle, and lower testicular volume. The live-birth model also discriminated well with a c statistic of 0.70 (0.64-0.76).

Conclusions

These results support the pragmatic counselling of couples diagnosed with azoospermia about the chances of success of the TESE procedure and of biological parenthood prior to surgical intervention. The models help to discriminate between men who have a high or low chance of successful TESE and couples who have a higher chance of achieving a live-birth after successful TESE. This will allow couples to make a better assessment of the balance of risk versus benefit prior to commitment to surgical interventions.

Prediction of the extent of germ cell loss utilising a noninvasive spectroscopy method in rat testicular damage model

The aim of this study is to investigate the efficiency of elastic light single-scattering spectroscopy system, a noninvasive method, to acquire spectra during testicular biopsy from normal and damaged seminiferous tubules with various degrees of germ cell loss. Adult control rats and doxorubicin-injected rats to achieve seminiferous germ cell loss (for 10 days [10D], 20 days [D20], 30 days [D30], 40 days [D40], and 50 days [D50]) were used. Spectroscopic measurements were acquired utilising a single-fibre optical probe, and histopathology of the biopsied testicular tissue samples were compared. Time-dependent testicular damage comprising various degrees of seminiferous tubule degeneration after doxorubicin-administration was observed. In D30, D40 and D50 groups, where significant germ cell loss was identified, elastic light single-scattering spectroscopy system signals were well correlated with disturbed spermatogenesis where significant differences in spectral signals were obtained. Our findings indicate that the elastic light single-scattering spectroscopy system has the potential to enable instant imaging of spermatogenesis in rats and could also be useful in humans for clinical applications, such as to increase sperm recovery success during micro-TESE for men with nonobstructive azoospermia.

Follicle-stimulating hormone may predict sperm retrieval rate and guide surgical approach in patients with non-obstructive azoospermia

Testicular sperm aspiration- (TESA) or micro-dissection testicular sperm extraction- (MD-TESE) combined intracytoplasmic sperm injection (ICSI) was the only option for non-obstructive azoospermia (NOA) patients to have a biological offspring and they had different success rates in sperm retrieval. Our study aimed to find predictor(s) for predicting the sperm retrieval rate (SRR) in NOAs and guide clinicians in choosing different surgical approaches, TESA or MD-TESE for NOAs. 294 NOAs who had undergone TESA or MD-TESE were divided into TESA group and MD-TESE group. Depending on sperm retrieval, each group was divided into two subgroups: successful subgroups and failure subgroups. They respectively were 24 cases and 131 cases, 53 cases and 86 cases. Clinical data, including body mass index (BMI), testicular volume, and serum hormone levels, were analyzed in a retrospective manner. The results showed that follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels and SRR were lower in TESA group as compared to these in MD-TESE group, while testicular volume was higher (P < 0.05). The surgical approach of sperm retrieval significantly affected the SRR (P < 0.05). In TESA subgroups, testicular volume, FSH and LH differed significantly (P < 0.05). In MD-TESE subgroups, the level of FSH and LH differed significantly between both groups (P < 0.05). Using logistics regression, we found a negative correlation (β=-0.083) between FSH and the SRR in TESA group but a positive correlation (β = 0.064) in MD-TESE group (P < 0.05). In conclusion, serum FSH level can predict the SRR of NOAs and guide the clinicians while selecting the suitable surgery approach for NOAs.

Over-expression of hsa_circ_0000116 in patients with non-obstructive azoospermia and its predictive value in testicular sperm retrieval

BACKGROUND

Non-obstructive azoospermia (NOA), identified in approximately 10% of infertile males, is a multifactorial disease whose molecular mechanisms remain unknown.

OBJECTIVES

The aim of this study was to identify the role of hsa_circ_0000116 in NOA and illustrate its predictive value in testicular sperm retrieval.

MATERIALS AND METHODS

The study included 78 individuals, 58 with NOA and 20 with obstructive azoospermia (OA). Serum hormones including testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and estradiol II (E2) were measured. Testicular histopathology was analyzed by at least two pathologists. The expression of hsa_circ_0000116 in testicular tissue samples was detected using real-time PCR, and the circRNA-miRNA-mRNA networks were predicted using bioinformatics analysis.

RESULTS

Our study illustrated that the expression of hsa_circ_0000116 was significantly higher in testicular tissue samples of NOA patients than in that of OA patients. Moreover, hsa_circ_0000116 was aberrantly expressed in three different pathological types of NOA: It was significantly up-regulated in patients with Sertoli cell-only syndrome (SCOS) when compared to patients with hypospermatogenesis (HS). In addition, the expression of hsa_circ_0000116 was negatively correlated with Johnsen score, while it was positively correlated with serum FSH level. A multivariate logistic regression model demonstrated that a high level of hsa_circ_0000116 was associated with a low rate of successful testicular sperm retrieval. Bioinformatics analysis and verification experiments showed that one of the most probable potential target miRNA for hsa_circ_0000116 was hsa-miR-449a. Further analysis indicated that hsa_circ_0000116 may be affecting the fertility function through a hsa_circ_0000116-miR-449-autophagy-related competing endogenous RNA (ceRNA) network.

DISCUSSION AND CONCLUSION

We report for the first time that hsa_circ_0000116 may play pivotal roles in regulating spermatogenesis and may also be a potential biomarker for the diagnosis and treatment of NOA, while acting as a predictive tool for the rate of successful testicular sperm retrieval in NOA patients.

A risk prediction model of sperm retrieval failure with fine needle aspiration in males with non-obstructive azoospermia

STUDY QUESTION

Can we predict the risk of sperm retrieval failure among men with non-obstructive azoospermia (NOA) before they undergo fine needle aspiration (FNA)?

SUMMARY ANSWER

Our model, which includes FSH level, age and testicular volume as variables, can predict the risk of sperm retrieval failure with FNA.

WHAT IS KNOWN ALREADY

Combined with ICSI, testicular sperm aspiration (TESA) can enable patients with NOA to have their own genetic offspring. Nearly all reproductive medicine centres in China have applied FNA, but approximately half of patients with NOA experience testicular sperm retrieval failure. Nevertheless, the models developed to predict the likelihood of obtaining spermatozoa with testicular sperm extraction (TESE) cannot accurately predict sperm retrieval, and few of these models have been sufficiently validated.

STUDY DESIGN, SIZE, DURATION

This study involved three cohorts including 597 men with NOA. From 1 January 2015 to 31 July 2017, a retrospective cohort of 317 males with NOA who underwent FNA procedures at a university affiliated hospital were included to build a risk prediction model of sperm retrieval failure with FNA. Then, from 25 October 2017 to 31 March 2018, two prospective cohorts of 61 and 219 males with NOA from the same hospital and one other reproductive specialist hospital respectively, were recruited to validate the risk prediction model.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) obtained with FNA. A binary multivariable logistic model was built to predict the risk of sperm retrieval failure after TESA using the dataset from the retrospective cohort. A cut-off value for risk was calculated with receiver operating characteristic (ROC) curve analysis. Two validation sets from the prospective cohort were used to validate the risk prediction model by measures including prediction accuracy and the true positive rate.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 327 (54.8%) males with NOA experienced sperm retrieval failure with FNA. FSH level, age and testicular volume were included in the prediction model for sperm retrieval failure risk. The model had an AUC of 82.3% (95% CI: 77.6–87.1%) and a cut-off value of 64.61% with a sensitivity of 0.677 and specificity of 0.863 for predicted risk. The predictive accuracies were 85.25 and 83.56% in the external validation sets from two centres. Specifically, 85.71 and 85.15% of NOA patients from two centres that experienced sperm retrieval failure were correctly identified using our model.

LIMITATIONS, REASONS FOR CAUTION

A small proportion of males with NOA in whom sperm were successfully retrieved with FNA were misclassified; therefore, TESA techniques with higher sperm retrieval rates may be attempted in patients with high predicted risks of sperm retrieval failure rather than terminating the efforts to produce a genetic offspring. In addition, the ability to achieve a live birth using sperm retrieved with FNA was not tested in this study.

WIDER IMPLICATIONS OF THE FINDINGS

We would recommend the use of micro-TESE for men with NOA and a high predicted risk of FNA failure.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partly supported by National Key R&D Program of China (No. 2017YFC0907305), the National Natural Science Foundation of China (No.81803332), Sichuan Science & Technology Program (No. 2018SZ0144, 2016SZ0066, 2018SZ0284 and 2018FZ0043), Chengdu Science & Technology Bureau (No. 2018-YF05-01265-SN), Postdoctoral Research foundation of Sichuan University (No. 2018SCU12012) and West China Second University Hospital of Sichuan University (No. kx027). There are no competing interests related to this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Prediction of sperm extraction in non-obstructive azoospermia patients: a machine-learning perspective

STUDY QUESTION

Can a machine-learning-based model trained in clinical and biological variables support the prediction of the presence or absence of sperm in testicular biopsy in non-obstructive azoospermia (NOA) patients?

SUMMARY ANSWER

Our machine-learning model was able to accurately predict (AUC of 0.8) the presence or absence of spermatozoa in patients with NOA.

WHAT IS KNOWN ALREADY

Patients with NOA can conceive with their own biological gametes using ICSI in combination with successful testicular sperm extraction (TESE). Testicular sperm retrieval is successful in up to 50% of men with NOA. However, to the best of our knowledge, there is no existing model that can accurately predict the success of sperm retrieval in TESE. Moreover, machine-learning has never been used for this purpose.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of 119 patients who underwent TESE in a single IVF unit between 1995 and 2017 was conducted. All patients with NOA who underwent TESE during their fertility treatments were included. The development of gradient-boosted trees (GBTs) aimed to predict the presence or absence of spermatozoa in patients with NOA. The accuracy of these GBTs was then compared to a similar multivariate logistic regression model (MvLRM).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We employed univariate and multivariate binary logistic regression models to predict the probability of successful TESE using a dataset from a retrospective cohort. In addition, we examined various ensemble machine-learning models (GBT and random forest) and evaluated their predictive performance using the leave-one-out cross-validation procedure. A cutoff value for successful/unsuccessful TESE was calculated with receiver operating characteristic (ROC) curve analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

ROC analysis resulted in an AUC of 0.807 ± 0.032 (95% CI 0.743–0.871) for the proposed GBTs and 0.75 ± 0.052 (95% CI 0.65–0.85) for the MvLRM for the prediction of presence or absence of spermatozoa in patients with NOA. The GBT approach and the MvLRM yielded a sensitivity of 91% vs. 97%, respectively, but the GBT approach has a specificity of 51% compared with 25% for the MvLRM. A total of 78 (65.3%) men with NOA experienced successful TESE. FSH, LH, testosterone, semen volume, age, BMI, ethnicity and testicular size on clinical evaluation were included in these models.

LIMITATIONS, REASONS FOR CAUTION

This study is a retrospective cohort study, with all the associated inherent biases of such studies. This model was used only for TESE, since micro-TESE is not performed at our center.

WIDER IMPLICATIONS OF THE FINDINGS

Machine-learning models may lay the foundation for a decision support system for clinicians together with their NOA patients concerning TESE. The findings of this study should be confirmed with further larger and prospective studies.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Division of Obstetrics and Gynecology, Soroka University Medical Center, there are no potential conflicts of interest for all authors.

Predictors of surgical sperm retrieval in non-obstructive azoospermia: summary of current literature

Intracytoplasmic sperm injection (ICSI), combined with surgical sperm retrieval (SR) techniques, is the sole option for patients with non-obstructive azoospermia to achieve fertility; however, with suboptimal results. Given the variability in clinical presentation, the potential role of factors that can predict the likelihood of successful testicular SR needs to be clarified. This article summarizes the current evidence concerning the variables predicting SR success in non-obstructive azoospermic patients with spermatogenic failure. For this, we used 60 articles, including 46 original papers and six meta-analyses. Clinical and laboratory factors, as well as adjuvant therapies and surgical retrieval methods, were the factors most commonly investigated. We found that Klinefelter syndrome, Y chromosome microdeletions in regions AZFa/b, and Sertoli cell-only histopathology were associated with reduced SR success. By contrast, testis volume > 12.5 ml, history of cryptorchidism, use of micro-TESE as the sperm retrieval method, and adjuvant therapy were associated with improved SR success. None of the predictors, alone or combined, provide definitive information about the chances of harvesting sperm in men with non-obstructive azoospermia, except for Y chromosome microdeletions in regions AZFa/b. In the latter, SR success is virtually nil. We conclude that SR outcomes in men with non-obstructive azoospermia are difficult to predict based on the existing variables. Although several predictors can be used for patient counseling, their clinical value is limited to either ensure SR success or discourage reproductive urologists from recommending SR to men with non-obstructive azoospermia seeking fertility. A notable exception includes the deletions involving the regions AZFa and/or AZFb of the Y chromosome; the affected patients should be counseled against undergoing SR.

Sperm recovery and ICSI outcomes in men with non-obstructive azoospermia: a systematic review and meta-analysis

BACKGROUND

Factor affecting sperm retrieval rate (SRR) or pregnancy rates (PR) after testicular sperm extraction (TESE) in patients with non-obstructive azoospermia (NOA) have not been systematically evaluated. In addition, although micro-TESE (mTESE) has been advocated as the gold standard for sperm retrieval in men with NOA, its superiority over conventional TESE (cTESE) remains conflicting.

OBJECTIVE AND RATIONALE

The objective was to perform a meta-analysis of the currently available studies comparing the techniques of sperm retrieval and to identify clinical and biochemical factors predicting SRR in men with NOA. In addition, PRs and live birth rates (LBRs), as derived from subjects with NOA post-ICSI, were also analysed as secondary outcomes.

SEARCH METHODS

An extensive Medline, Embase and Cochrane search was performed. All trials reporting SRR derived from cTESE or mTESE in patients with NOA and their specific determinants were included. Data derived from genetic causes of NOA or testicular sperm aspiration were excluded.

OUTCOMES

Out of 1236 studies, 117 studies met the inclusion criteria for this study, enrolling 21 404 patients with a mean age (± SD) of 35.0 ± 2.7 years. cTESE and mTESE were used in 56 and 43 studies, respectively. In addition, 10 studies used a mixed approach and 8 studies compared cTESE with mTESE approach. Overall, a SRR per TESE procedure of 47[45;49]% (mean percentage [95% CI]) was found. No differences were observed when mTESE was compared to cTESE (46[43;49]% for cTESE versus 46[42;49]% for mTESE). Meta-regression analysis demonstrated that SRR per cycle was independent of age and hormonal parameters at enrolment. However, the SRR increased as a function of testis volume. In particular, by applying ROC curve analysis, a mean testis volume higher than 12.5 ml predicted SRR >60% with an accuracy of 86.2% ± 0.01. In addition, SRR decreased as a function of the number of Klinefelter's syndrome cases included (S = -0.02[-0.04;-0.01]; P < 0.01. I = 0.12[-0.05;0.29]; P = 0.16). Information on fertility outcomes after ICSI was available in 42 studies. Overall, a total of 1096 biochemical pregnancies were reported (cumulative PR = 29[25;32]% per ICSI cycle). A similar rate was observed when LBR was analysed (569 live births with a cumulative LBR = 24[20;28]% per ICSI cycle). No influence of male and female age, mean testis volume or hormonal parameters on both PR and LBR per ICSI cycle was observed. Finally, a higher PR per ICSI cycle was observed when the use of fresh sperm was compared to cryopreserved sperm (PR = 35[30;40]%, versus 20[13;29]% respectively): however, this result was not confirmed when cumulative LBR per ICSI cycle was analysed (LBR = 30[20;41]% for fresh versus 20[12;31]% for cryopreserved sperm).

WIDER IMPLICATIONS

This analysis shows that cTESE/mTESE in subjects with NOA results in SRRs of up to 50%, with no differences when cTESE was compared to mTESE. Retrieved sperms resulted in a LBR of up to 28% ICSI cycle. Although no difference between techniques was found, to conclusively clarify if one technique is superior to the other, there is a need for a sufficiently powered and well-designed randomized controlled trial to compare mTESE to cTESE in men with NOA.

Determining an optimal cut-off value for follicle-stimulating hormone to predict microsurgical testicular sperm extraction outcome in patients with non-obstructive azoospermia

Objective To determine the optimal cut-off value for follicle stimulating hormone (FSH) to predict the outcome of microsurgical testicular sperm extraction (micro-TESE) in patients with nonobstructive azoospermia (NOA). Subjects and methods We included a total number of 180 patients with NOA. The serum level of FSH was determined and all the subjects underwent micro-TESE. We determined the optimal cut-off value for FSH and assessed whether the test could be effectively used as a successful predictor of sperm retrieval by calculating the Receiver Operating Characteristic (ROC) area under the curve. Results Overall we included a total number of 171 patients with mean age of 34.3 ± 8.6 years. The micro-TESE was considered to be successful in 79 (43.8%) while it failed in 92 (56.2%) patients. We found that the mean level of serum FSH was significantly higher in group those with failed micro-TEST compared to successful group (p < 0.001). The cut-off value for FSH was calculated to be 14.6 mIU/mL to predictive the outcome of micro-TESE with a sensitivity of 83.5% [73.5%-90.9%] and a specificity of 80.3% [69.5%-88.5%]. At this value, the other parameters were calculated to be PPV, 81.5%; NPV, 82.4; LR+, 4.23; and LR-, 0.21. Conclusions The results of the current study indicate that FSH plasma levels above 14.6 mIU/mL can be considered to be the failure predictor of the micro-TESE in NOA patients.

Prediction model for testis histology in men with non-obstructive azoospermia: evidence for a limited predictive role of serum follicle-stimulating hormone

PURPOSE

The present prediction model was intended to verify whether serum FSH level could be predictive of testis histology in patients with non-obstructive azoospermia (NOA).

METHODS

We evaluated two datasets of patients with NOA: the first (San Paolo dataset) comprising 558 patients, 18-63 years old, the second (Procrea dataset) composed by 143 patients, 26-62 years old; bot datasets were combined to obtain a validation set. Multinomial logistic regression was first run with serum FSH and testis volume as independent predictors of testis histology, then, the correctly classified histological subcategories were set as outcome variables of a prediction model in both development and validation sets.

RESULTS

Multinomial logistic regression showed that FSH was a significant predictor of testis histology in 58% of cases, although it was unable to correctly classify cases with focal SCO or maturation arrest (MA). A prediction model was then run with hypospermatogenesis (HYPO) and Sertoli-only syndrome (SCO) as outcome variables of a binary logistic regression. FSH significantly predicted both HYPO and SCO, with a sensitivity of 40.9 and 80.7 and a specificity of 84.3 and 46.8 respectively. The model showed a fair discriminative ability (ROC AUC 0.705 and 0.709 respectively) and was adequately calibrated.

CONCLUSIONS

Supported by a robust statistical analysis, we conclude that serum FSH level cannot be considered a prognostic marker of spermatogenic dysfunction in patients with NOA.

Risk factors affecting post-pubertal high serum follicle-stimulating hormone in patients with hypospadias

Purpose

The factors affecting spermatogenesis in adulthood in patients with hypospadias (HS) are not clearly understood. In the present study, risk factors affecting post-pubertal high serum follicle-stimulating hormone (FSH) were evaluated in patients with HS.

Materials and methods

Among those with a history of HS surgery, patients in whom endocrinological evaluation regarding pituitary–gonadal axis was performed at 15 years of age or older between March 2004 and April 2018 were enrolled in the present study. High serum FSH was defined as greater than 10 mIU/ml. The severity of HS was divided into mild and severe. Factors affecting the post-pubertal high serum FSH were estimated.

Results

Seventy-nine patients were included in the present study. The severity of HS was mild in 35 and severe in 44. History of undescended testis (UDT) was confirmed in 12. High serum FSH was detected in nine. On logistic regression model analysis, a history of UDT was the only significant factor for high serum FSH. The incidence of high serum FSH in patients with UDT was significantly higher than that in those without UDT (58.3% vs 7.5%, p < 0.01). When stratified by severity of HS and the presence of UDT, high serum FSH was detected in 70% in patients with severe HS and UDT, whereas less than 10% in other groups.

Conclusions

A history of UDT was a significant factor for post-pubertal high serum FSH in patients with HS. Accordingly, the presence of UDT may be a marker for impaired spermatogenesis in patients with HS, especially in severe cases.

Analysis of factors affecting repeat microdissection testicular sperm extraction outcomes in infertile men

OBJECTIVE

There is no clear consensus on which patients and how many of microscopic testicular sperm extraction (mTESE) procedures will be successful. In this study, we aimed to evaluate the sperm retrieval rates and factors affecting these rates in men who underwent repeat mTESEs.

MATERIAL AND METHODS

A total of 346 patients who underwent mTESE for sperm retrieval were included in the study. Patients were divided into groups according to the number of mTESE operations. Patients' karyotype, follicle-stimulating hormone (FSH) and testosterone levels, varicocele presence, and testis volumes were recorded from patient files. The sperm retrieval rates were compared between groups, and predicting factors for successful sperm retrieval were evaluated.

RESULTS

Microscopic TESE was applied for the first time in 244 patients, 1-2 times in 73 patients, and 3-4 times in 29 patients. There was a significant difference between groups in preoperative FSH values and postoperative testicular histopathology (p=0.004 and p<0.001). The sperm retrieval rate in the group of patients who had not undergone previous TESE was higher than the group of patients that had undergone TESE for 1-2 times and 3-4 times (p=0.028). In addition, testicular volume, histology, karyotype, and Y-chromosome microdeletion were predicting factors for successful sperm retrieval (p=0.011, p=0.039, p=0.002, and p<0.001, respectively).

CONCLUSION

Our results confirm the necessity for repeat mTESE operations to be performed by experienced surgeons in reference centers to optimize the chance of reduced sperm retrieval rates with recurrent biopsies.

Predictive significance of serum inhibin B on testicular haploid gamete retrieval outcomes in nonobstructive azoospermic men

The purpose of this study was to determine the diagnostic accuracy of serum inhibin B (INHB) as a predictor of the retrieval outcome of testicular haploid gametes (spermatids and testicular spermatozoa) in nonobstructive azoospermic men. Serum hormone levels, testicular volume, and histological evaluation were performed in 403 Chinese nonobstructive azoospermic men. Testicular haploid gamete was successfully retrieved in 213 of 403 patients (52.85%). The haploid gamete group always had higher INHB levels than the non-haploid gamete group. According to the receiver operating characteristic (ROC) curve analysis, INHB was a good predictor of testicular haploid gamete retrieval outcome in all patients (sensitivity: 77.93% and specificity: 91.58%) and patients with normal follicle-stimulating hormone (FSH; sensitivity: 88.52% and specificity: 70.83%). The area under the ROC curve (AUC) of INHB was similar to that of FSH in all patients or patients with normal FSH. In patients with elevated FSH, INHB was superior to FSH in predicting the presence of haploid gamete (AUC: 0.73 vs 0.55, P < 0.05), with a sensitivity of 60.00% and a specificity of 80.28%. It concluded that serum INHB as an effective marker for spermatogenesis was a significant predictor of testicular haploid gamete retrieval outcomes in nonobstructive azoospermic men. Especially, INHB is superior to FSH in predicting the presence of haploid gamete in the patients with elevated FSH.

Preclinical evaluation of a TEX101 protein ELISA test for the differential diagnosis of male infertility

BACKGROUND

TEX101 is a cell membrane protein exclusively expressed by testicular germ cells and shed into seminal plasma. We previously verified human TEX101 as a biomarker for the differential diagnosis of azoospermia, and developed a first-of-its-kind TEX101 ELISA. To demonstrate the clinical utility of TEX101, in this work we aimed at evaluating ELISA performance in a large population of fertile, subfertile, and infertile men.

METHODS

Mass spectrometry, size-exclusion chromatography, ultracentrifugation, and immunohistochemistry were used to characterize TEX101 protein as an analyte in seminal plasma. Using the optimized protocol for seminal plasma pretreatment, TEX101 was measured by ELISA in 805 seminal plasma samples.

RESULTS

We demonstrated that TEX101 was present in seminal plasma mostly in a free soluble form and that its small fraction was associated with seminal microvesicles. TEX101 median values were estimated in healthy, fertile pre-vasectomy men (5436 ng/mL, N = 64) and in patients with unexplained infertility (4967 ng/mL, N = 277), oligospermia (450 ng/mL, N = 270), and azoospermia (0.5 ng/mL, N = 137). Fertile post-vasectomy men (N = 57) and patients with Sertoli cell-only syndrome (N = 13) and obstructive azoospermia (N = 36) had undetectable levels of TEX101 (≤0.5 ng/mL). A cut-off value of 0.9 ng/mL provided 100% sensitivity at 100% specificity for distinguishing pre- and post-vasectomy men. The combination of a concentration of TEX101 > 0.9 ng/mL and epididymis-specific protein ECM1 > 2.3 μg/mL provided 81% sensitivity at 100% specificity for differentiating between non-obstructive and obstructive azoospermia, thus eliminating the majority of diagnostic testicular biopsies. In addition, a cut-off value of ≥0.6 ng/mL provided 73% sensitivity at 64% specificity for predicting sperm or spermatid retrieval in patients with non-obstructive azoospermia.

CONCLUSIONS

We demonstrated the clinical utility of TEX101 ELISA as a test to evaluate vasectomy success, to stratify azoospermia forms, and to better select patients for sperm retrieval.

Prediction model for obtaining spermatozoa with testicular sperm extraction in men with non-obstructive azoospermia

STUDY QUESTION

Can an externally validated model, based on biological variables, be developed to predict successful sperm retrieval with testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA) using a large nationwide cohort?

SUMMARY ANSWER

Our prediction model including six variables was able to make a good distinction between men with a good chance and men with a poor chance of obtaining spermatozoa with TESE.

WHAT IS KNOWN ALREADY

Using ICSI in combination with TESE even men suffering from NOA are able to father their own biological child. Only in approximately half of the patients with NOA can testicular sperm be retrieved successfully. The few models that have been developed to predict the chance of obtaining spermatozoa with TESE were based on small datasets and none of them have been validated externally.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective nationwide cohort study. Data from 1371 TESE procedures were collected between June 2007 and June 2015 in the two fertility centres.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) in the testicular biopsies.We constructed a model for the prediction of successful sperm retrieval, using univariable and multivariable binary logistic regression analysis and the dataset from one centre. This model was then validated using the dataset from the other centre. The area under the receiver-operating characteristic curve (AUC) was calculated and model calibration was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 599 (43.7%) successful sperm retrievals after a first TESE procedure. The prediction model, built after multivariable logistic regression analysis, demonstrated that higher male age, higher levels of serum testosterone and lower levels of FSH and LH were predictive for successful sperm retrieval. Diagnosis of idiopathic NOA and the presence of an azoospermia factor c gene deletion were predictive for unsuccessful sperm retrieval. The AUC was 0.69 (95% confidence interval (CI): 0.66-0.72). The difference between the mean observed chance and the mean predicted chance was <2.0% in all groups, indicating good calibration. In validation, the model had moderate discriminative capacity (AUC 0.65, 95% CI: 0.62-0.72) and moderate calibration: the predicted probability never differed by more than 9.2% of the mean observed probability.

LIMITATIONS, REASONS FOR CAUTION

The percentage of men with Klinefelter syndrome among men diagnosed with NOA is expected to be higher than in our study population, which is a potential selection bias. The ability of the sperm retrieved to fertilize an oocyte and produce a live birth was not tested.

WIDER IMPLICATIONS OF THE FINDINGS

This model can help in clinical decision-making in men with NOA by reliably predicting the chance of obtaining spermatozoa with TESE.

STUDY FUNDING/COMPETING INTEREST

This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design nor elaboration of this study.

TRIAL REGISTRATION NUMBER

Not applicable.