Etiology of azoospermia in a military population

Nonobstructive azoospermia: an etiologic review

ABSTRACT

Azoospermia is the complete absence of spermatozoa in the ejaculate in two or more semen analyses after centrifugation. Nonobstructive azoospermia (NOA) represents the most severe form of male factor infertility accounting for 10%-15% of cases and stems from an impairment to spermatogenesis. Understanding of the hypothalamic-pituitary-testicular axis has allowed NOA to be subcategorized by anatomic and/or pathophysiologic level. The etiologies of NOA, and therefore, the differential diagnoses when considering NOA as a cause of male factor infertility, can be subcategorized and condensed into several distinct classifications. Etiologies of NOA include primary hypogonadism, secondary hypogonadism, defects in androgen synthesis and/or response, defective spermatogenesis and sperm maturation, or a mixed picture thereof. This review includes up-to-date clinical, diagnostic, cellular, and histologic features pertaining to the multitude of NOA etiologies. This in turn will provide a framework by which physicians practicing infertility can augment their clinical decision-making, patient counseling, thereby improving upon the management of men with NOA.

Does the FNA sperm retrieval failure prediction model work well for current NOA individuals undertaking risk screening before the operation? Model validation, high-risk population identification and potential alternative sperm retrieval exploration

BACKGROUND

Non-obstructive azoospermia (NOA), the severe type of male infertility. The objective of this study was to evaluate the predictive accuracy of a prediction model of sperm retrieval failure with fine needle aspiration (FNA).

METHODS

This study involved 769 NOA patients (dataset 1) undertaking FNA and 140 NOA patients undertaking mTESE (dataset 2). The previous model was validated and then reconstructed for more potential risk factors and better accuracy in dataset 1. The reconstructed model was evaluated in NOA patients with different new variables. The outcomes of the micro- testicular sperm extraction (mTESE) were compared with the predicted outcomes of FNA to evaluate its potential as an alternative surgical sperm retrieval (SSR) technique.

RESULTS

307 (39.92%) males experienced sperm retrieval failure in FNA while 92 (65.7%) males experienced sperm retrieval failure in mTESE. The refined model has 80% overall agreement (n = 616). The reconstructed model had an AUROC of 0.876 (95% CI: 0.850-0.921). The mTESE has significantly higher success rate (34.29%) than the predicted success rate of FNA (5.71%).

CONCLUSIONS

Previous model shows good consistency. mTESE can be an alternative SSR method for NOA patients with a high predicted risk of sperm retrieval failure with FNA.

Role of varicocele repair in the era of assisted reproductive technologies: Lessons from 2000 cases of microsurgical varicocele repair

Backgrounds

In an era of advanced maternal age, there is less conclusive evidence regarding the treatment outcomes of varicocele repair for assisted reproductive technology (ART). Progress in basic research on varicocele is notable whereas there are many clinically relevant points to discuss.

Methods

Based on our experience with more than 2000 cases of microsurgical varicocele repair, we focused on the effectiveness of varicocele repair, pathophysiology, surgical approaches, contributions to ART, sperm DNA fragmentation, and varicocele-associated azoospermia in this review with the aim of identifying clearer directions for basic and clinical research on varicocele.

Results

Microsurgical low ligation for varicocele repair is expected to remain the gold standard for surgical therapy. Based on the findings from a number of systematic reviews and meta-analyses, negative opinions regarding the efficacy of microsurgical varicocele repair in male infertility treatment have become virtually nonexistent. However, the majority of evidence regarding surgical indications and effectiveness pertains to improvements in semen parameters or non-ART pregnancy rates.

Conclusions

Further understandings regarding to pathophysiology of varicocele will likely be gained through comprehensive genetic, transcriptomic, and epigenetic analyses using blood and testicular samples from humans and we hope to develop new diagnostic methods and pharmacotherapy.

Identification of active spermatogenesis using a multiphoton microscope

BACKGROUND

The sperm retrieval rate of microdissection testicular sperm extraction varies from 25% to 60%. Therefore, it is necessary to establish objective selection criteria for identifying seminiferous tubules with spermatozoa.

OBJECTIVES

Our aim was to develop a method for identifying spermatogenesis without sectioning testicular tissues.

MATERIALS AND METHODS

Testicular tissues of 10-week-old normal rats were fixed with 4% paraformaldehyde. Fluorescent labeling of seminiferous tubule nuclei and F-actin was performed, and the specimens were observed without sectioning using a multiphoton microscope. Cryptorchid rats were used as a model lacking elongated spermatids. Multiphoton images were compared with images of normal seminiferous tubules. In addition, seminiferous tubules of 10-week-old normal rats were labeled by testicular interstitial injection of fluorescent probes and observed by a multiphoton microscope without fixation. Terminal deoxynucleotidyl transferase dUTP nick end labeling-stained images of normal and probe-injected testes were compared.

RESULTS

In fixed seminiferous tubules, elongated spermatids were identified. In addition, F-actin of apical ectoplasmic specialization was observed around elongated spermatids. Furthermore, spermatogenic stages were identified by an array of nuclei or F-actin. In cryptorchid testes, elongated spermatids and F-actin of the apical ectoplasmic specialization were not observed. In testes injected with fluorescent probes, F-actin of the apical ectoplasmic specialization was observed, and spermatogenic stages were identified without fixation. There was no significant difference in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells per seminiferous tubule between normal and probe-injected testes.

CONCLUSIONS

Seminiferous epithelium could be observed without sectioning of tissues by fluorescent probes and a multiphoton microscope. Active spermatogenesis was observed by labeling F-actin with and without fixation. Moreover, the toxicity of fluorescent probes was limited. Our method has a potential for live imaging of testicular tissue.

Staged Laboratory Processing of Testicular Tissue in Non-Obstructive Azoospermia May Rescue Retrieving an Existing Sperm: A Case Report and Literature Review

Non-obstructive azoospermia (NOA) is the most difficult form of male infertility to manage. It usually requires sperm retrieval from the testis, which is most challenging due to sperm rarity. Here, we describe the recovery of testicular sperms that had been missing and whose original retrieval results were negative. Salvage microsurgical testicular sperm extraction and sperm testing were performed on a 36-year-old male with NOA. Neither in the operation room nor after an inspection in the embryology laboratory were any sperm detected. The obtained tissue was advised to be frozen because the patient data and surgical microscopy predicted a favorable outcome, and the tissue processing was done in an inappropriate environment. About 1 month later, the specimen was thawed, crushed, and re-examined. Successful oocyte fertilization resulted from an effective detection of sperms and their direction to intra-cytoplasmic sperm injection. This is the first case report that, to the best of our knowledge, describes the stepwise laboratory processing of testicular tissue and its capacity to recover lost sperms in challenging NOA cases and under less-than-ideal working conditions.

Association of occupations with decreased semen quality in eastern China: a cross-sectional study of 12 301 semen donors

OBJECTIVES

This study aims to examine the association between occupational factors and semen quality in semen donors in eastern China.

METHODS

We recruited 12 301 semen donors from 2006 to 2020 as the studying population. A self-designed questionnaire was applied for collecting lifestyle and work style information. Semen samples were analysed according to WHO guidelines. A crude and adjusted linear regression model was used to analyse the association between occupational factors and semen quality.

RESULTS

College students accounted for 36.2% of all semen donors. The majority (81.3%) of semen donors were between 18 year and 30 years. Soldiers or the police had the highest semen volume (the median value=3.8 mL), however, they had the lowest sperm concentration (53.6×10⁶/ml) and sperm motility (45.5%). Workers in finance or insurance had an elevated risk of low semen volume, sperm concentration and total sperm count (OR=1.43, 1.57 and 1.98, respectively). Unemployed men had a high risk of low sperm concentration and low total sperm count (OR=1.84 and 1.58, respectively). Working in the information technology industry had a deleterious effect on the progressive motility of sperm (OR=1.27, 95% CI 1.03 to 1.57).

CONCLUSION

Our study indicated that sedentary work style and intensive sports in certain professions might be associated with decreased semen quality. We reported evidence of becoming unemployed on the damage to semen quality. Hence, we advocate a healthy work style to improve semen quality in eastern China.

The male infertility evaluation still matters in the era of high efficacy assisted reproductive technology

Today's reproductive endocrinology and infertility providers have many tools at their disposal when it comes to achieving pregnancy. In the setting of highly efficacious assisted reproductive technology, it is natural to assume that male factor infertility can be overcome by acquiring sperm and then bypassing the male evaluation. In this review, we go through guideline statements and a stepwise male factor infertility evaluation to propose that a thorough male evaluation remains important to optimize pregnancy and live birth. The foundation of this parallel evaluation is referral to a reproductive urologist for the optimization of the male partner, for advanced diagnostics and interventions, and for the detection of other underlying male pathology. We also discuss what future developments might have an impact on the workup of the infertile male.

Varicocele treatment in non-obstructive azoospermia: a systematic review

Objective: To review the available literature and identify factors associated with successful outcomes after varicocele repair (VR) in the setting of non-obstructive azoospermia (NOA). Methods: The PubMed and EMBASE databases were searched for relevant articles. Primary outcomes were return of spontaneous spermatogenesis, sperm retrieval rates (SRRs), and unassisted and assisted pregnancy rates. Histopathological subtypes, when available, were used for subgroup analysis. Results: A total of 16 articles were finally included. The average sample size was 43 and average duration of follow-up was 10.5 months. The average rate of primary spermatogenesis after VR was 27.3%. The average SRR, across five studies in men with NOA undergoing microscopic testicular sperm extraction status after varicocelectomy, was 48.9% vs 32.1% for the untreated cohort groups, and the average spontaneous pregnancy rate was 5.24%. Histopathology subtype was a significant contributing factor when analysed. Conclusion: Varicocele repair should be considered in men with NOA, as it may allow some patients to avoid assisted reproductive technologies and improves success rates when utilised.

Genetic testing for men with infertility: techniques and indications

Genetic testing is an integral component in the workup of male infertility as genetic conditions may be responsible for up to 15% of all cases. Currently, three genetic tests are commonly performed and recommended by major urologic associations: karyotype analysis (KA), Y-chromosome microdeletion testing, and CFTR mutation testing. Despite widespread adoption of these tests, an etiology for infertility remains elusive in up to 80% of cases. Recent work has identified intriguing new targets for genetic testing which may soon see clinical relevance. This review will discuss the indications and techniques for currently offered genetic tests and briefly explore ongoing research directions within this field.

Round spermatid injection into human oocytes: a systematic review and meta-analysis

Many azoospermic men do not possess mature spermatozoa at the time of surgical sperm extraction. This study is a systematic review and meta-analysis evaluating outcomes following round spermatid injection (ROSI), a technique which utilizes immature precursors of spermatozoa for fertilization. An electronic search was performed to identify relevant articles published through October 2018. Human cohort studies in English involving male patients who had round spermatids identified and used for fertilization with human oocytes were included. Fertilization rate, pregnancy rate, and resultant delivery rate were assessed following ROSI. Meta-analysis outcomes were analyzed using a random-effects model. Data were extracted from 22 studies involving 1099 couples and 4218 embryo transfers. The fertilization rate after ROSI was 38.7% (95% confidence interval [CI]: 31.5%-46.3%), while the pregnancy rate was 3.7% (95% CI: 3.2%-4.4%). The resultant delivery rate was low, with 4.3% of embryo transfers resulting in a delivery (95% CI: 2.3%-7.7%). The pregnancy rate per couple was 13.4% (95% CI: 6.8%-19.1%) and the resultant delivery rate per couple was 8.1% (95% CI: 6.1%-14.4%). ROSI has resulted in clinical pregnancies and live births, but success rates are considerably lower than those achieved with mature spermatozoa. While this technique may be a feasible alternative for men with azoospermia who decline other options, couples should be aware that the odds of a successful delivery are greatly diminished and the prognosis is relatively poor.

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.

Diagnosis of Partial Retrograde Ejaculation in Non-Azoospermic Infertile Men with Low Semen Volume

In non-azoospermic patients with low semen volume (LSV), looking for partial retrograde ejaculation (PRE) by searching sperm in the postejaculatory urine (PEU) is required. The use of a retro-ejaculatory index (R-ratio) was suggested to define PRE, but none of the studies indicated a specific threshold above which PRE must be considered. Our objective was to propose a threshold value for the R-ratio as indicative of PRE in patients with LSV selected to be devoid of any known causes or risk factors for retrograde ejaculation or LSV. Among our data base (2000–2009) including 632 patients with PEU, 245 male patients from infertile couples who had had a first semen analysis with LSV (< 2mL) and a second semen analysis associated with PEU, were selected on the previous criteria. A prospective control group was randomly constituted (2007–2008) of 162 first consulting male patients from infertile couples, with a normal semen volume (≥ 2mL) on a first semen analysis and who accepted to collect PEU with their usual second semen analysis, selected on the previous criteria. To define an R-ratio threshold indicative of PRE, we used a ROC curve analysis and a regression tree based on a classification and regression tree (CART) algorithm. Of the 245 LSV patients, 146 still presented low semen volume (< 2 mL) on the second semen analysis. From the use of the CART algorithm, two low (1.5% and 2.8%) and two high R-values (7.1% and 8.3%) were defined, according to the lower reference limit for semen volume of 2.0 mL (WHO 1999) or 1.5 mL (WHO 2010) respectively. As only one or no patient with normal semen volume was observed above the two high R-values, we suggest an R-value higher than the range of [7.1–8.3]% as indicative of PRE until confirmation by a prospective multicenter study.

Transitional Urology for Male Adolescents: What Adult Urologists Should Know

In recent years, there has been increasing interest in transitional urology, or how to best prepare patients with major congenital urologic diseases, such as bladder exstrophy and neuropathic bladder, to manage their own health care with adult urologists. However, common pediatric urologic conditions may be encountered by the adult urologist with more regularity. This review focuses on three relatively common conditions which may be identified in childhood, the consequences from which a patient may seek help from an adult urologist: cryptorchidism, varicocele, and Klinefelter syndrome.

Recurrent Microdeletions at Xq27.3-Xq28 and Male Infertility: A Study in the Czech Population

Background

Genetic causes of male infertility are hypothesized to involve multiple types of mutations, from single gene defects to complex chromosome rearrangements. Recently, several recurrent X-chromosome microdeletions (located in subtelomeric region of the long arm) were reported to be associated with male infertility in Spanish and Italian males. The aim of our study was to test their prevalence and infertility association in population of men from the Czech Republic.

Methods

107 males with pathological sperm evaluation resulting in nonobstructive infertility were compared to 131 males with normal fecundity. X-chromosome microdeletions were assessed by +/- PCR with three primer pairs for each region Xcnv64 (Xq27.3), Xcnv67 (Xq28) and Xcnv69 (Xq28). The latter microdeletion was further characterized by amplification across the deleted region, dividing the deletion into three types; A, B and C.

Results

We detected presence of isolated Xcnv64 deletion in 3 patients and 14 controls, and Xcnv69 in 3 patients and 6 controls (1 and 1 patient vs.4 and 1 control for types A and B respectively). There was one control with combined Xcnv64 and Xcnv69 type B deletions, and one patient with combination of Xcnv64 and Xcnv69 type C deletions. The frequency of the deletions was thus not higher in patient compared to control group, Xcnv64 was marginally associated with controls (adjusted Fisher´s exact test P = 0.043), Xcnv69 was not associated (P = 0.452). We excluded presence of more extensive rearrangements in two subjects with combined Xcnv64 and Xcnv69 deletions. There was no Xcnv67 deletion in our cohort.

Conclusion

In conclusion, the two previously reported X-linked microdeletions (Xcnv64 and Xcnv69) do not seem to confer a significant risk to impaired spermatogenesis in the Czech population. The potential clinical role of the previously reported patient-specific Xcnv67 remains to be determined in a larger study population.

Long-Term Outcome of Low Scrotal Approach Orchiopexy without Ligation of the Processus Vaginalis

PURPOSE

We performed low scrotal approach orchiopexy in patients with prescrotal cryptorchidism. The processus vaginalis was not ligated if it was not widely patent. We retrospectively evaluated the long-term outcomes of low scrotal approach orchiopexy without processus vaginalis ligation.

MATERIALS AND METHODS

A total of 137 patients (227 testes) were diagnosed with prescrotal cryptorchidism between October 2009 and April 2014. All patients underwent low scrotal approach orchiopexy. Mean age at surgery was 34.9 months. The processus vaginalis was deemed to be not widely patent when a sound could not be passed into the abdominal cavity through the internal inguinal ring, and the processus vaginalis was not ligated in such cases.

RESULTS

Intraoperative findings revealed that the processus vaginalis was widely patent in 10 testes and was not widely patent in 217. A widely patent processus vaginalis was closed via scrotal approach in 5 testes, while an inguinal approach was necessary in 5. Median followup was 44 months (range 20 to 73). Postoperative complications included reascending testis in 1 case where an inguinal approach was necessary. No patient manifested testicular atrophy or inguinal hernia.

CONCLUSIONS

Low scrotal approach orchiopexy is a useful and safe procedure for treating patients with prescrotal cryptorchidism. Ligation is unnecessary when the processus vaginalis is not widely patent.