Predictive model to estimate the chances of successful sperm retrieval by testicular sperm aspiration in patients with nonobstructive azoospermia

Non-Obstructive Azoospermia and Intracytoplasmic Sperm Injection: Unveiling the Chances of Success and Possible Consequences for Offspring

Non-obstructive azoospermia (NOA) is found in up to 15% of infertile men. While several causes for NOA have been identified, the exact etiology remains unknown in many patients. Advances in assisted reproductive technology, including intracytoplasmic sperm injection (ICSI) and testicular sperm retrieval, have provided hope for these patients. This review summarizes the chances of success with ICSI for NOA patients and examines preoperative factors and laboratory techniques associated with positive outcomes. Furthermore, we reviewed possible consequences for offspring by the use of ICSI with testicular sperm retrieved from NOA patients and the interventions that could potentially mitigate risks. Testicular sperm retrieved from NOA patients may exhibit increased chromosomal abnormalities, and although lower fertilization and pregnancy rates are reported in NOA patients compared to other forms of infertility, the available evidence does not suggest a significant increase in miscarriage rate, congenital malformation, or developmental delay in their offspring compared to the offspring of patients with less severe forms of infertility or the offspring of fertile men. However, due to limited data, NOA patients should receive specialized reproductive care and personalized management. Counseling of NOA patients is essential before initiating any fertility enhancement treatment not only to mitigate health risks associated with NOA but also to enhance the chances of successful outcomes and minimize possible risks to the offspring.

A detection model of testis-derived circular RNAs in serum for predicting testicular sperm retrieval rate in non-obstructive azoospermia patients

BACKGROUND

Microdissection testicular sperm extraction is an effective method to retrieve sperm from non-obstructive azoospermia patients. However, its successful rate is less than 50%.

OBJECTIVES

To identify the predictive value of circular RNAs in serum for sperm retrieval rate in non-obstructive azoospermia patients.

MATERIALS AND METHODS

180 non-obstructive azoospermia patients were recruited in this study, including 84 individuals with successful sperm retrieval and 96 individuals with failed sperm retrieval. Our study contained two phases. First, 20 patients, selected from the 180 patients, were included in screening cohort. In this cohort, the top 20 circular RNAs from our previous testicular circRNA profiles were verified between successful and failed sperm retrieval groups using real-time polymerase chain reaction. Six circular RNAs with the most significantly different expressions were selected for further verification. Second, the 180 patients were included as discovery cohort to verify the six circular RNAs. Circular RNAs were extracted from serum in each participant. Logistic regression analysis was further performed to identify the predictive value and the area under the curve analysis was used to evaluate diagnostic efficiency, sensitivity, and specificity.

RESULTS

Six circular RNAs including hsa_circ_0058058, hsa_circ_0008045, hsa_circ_0084789, hsa_circ_0000550, hsa_circ_0007422, and hsa_circ_0004099 showed aberrant expressions between the successful and failed sperm retrieval group. In addition, both single-circular RNA panels and multi-circular RNA panels were finally verified to be significant in predicting sperm retrieval rate. Notably, multi-circular RNAs panels demonstrated better predictive abilities compared with single-circRNA panels, and the combined panel of six-circular RNAs (risk score = 1.094×hsa_circ_0058058+0.697×hsa_circ_0008045+0.718×hsa_circ_0084789-0.591×hsa_circ_0000550-0.435×hsa_circ_0007422-1.017×hsa_circ_0004099-1.561) exhibited the best predictive ability in the present study with an AUC of 0.977, a sensitivity of 91.7% and a specificity of 86.5%. A higher risk score indicated a higher risk of failure in sperm retrieval.

DISCUSSION AND CONCLUSION

Our study was the first to report that testis-derived circular RNAs in serum have the ability to predict sperm retrieval rate in non-obstructive azoospermia patients, whether it is a single-circular RNA or a combination of multi-circular RNAs.

Improving outcomes of assisted reproductive technologies using artificial intelligence for sperm selection

Within the field of assisted reproductive technology, artificial intelligence has become an attractive tool for potentially improving success rates. Recently, artificial intelligence-based tools for sperm evaluation and selection during intracytoplasmic sperm injection (ICSI) have been explored, mainly to improve fertilization outcomes and decrease variability within ICSI procedures. Although significant advances have been achieved in developing algorithms that track and rank single sperm in real-time during ICSI, the clinical benefits these might have in improving pregnancy rates from a single assisted reproductive technology cycle remain to be established.

Testicular Core Extraction: Important Technique for Determining Sperm Retrieval Method in Non-obstructive Azoospermia

OBJECTIVE

To assess the value of preliminary testicular core extraction (TCE) as a tool for determining whether to pursue clinic testicular extraction (cTESE) versus microscopic testicular sperm extraction (mTESE) to minimize both financial burden and procedural complexity.

METHODS

All men with non-obstructive azoospermia (NOA) from 2018 to 2022 who underwent clinic TCE were analyzed. Patients who were found to have sperm on initial TCE were recommended cTESE. Patients who did not have sperm on initial TCE were recommended for mTESE. Sensitivity, specificity, positive predictive value, and negative predictive value of TCE were calculated. Cost reductions were determined based on this institution's fees. A nonparametric Wilcoxon test was performed to determine statistical significance between the results of the TCE sperm present and sperm absent groups.

RESULTS

Of the 82 NOA patients undergoing TCE, 51 (62.2%) core biopsies were positive for sperm and 31 (37.8%) were negative for sperm. The SRR for 35 men who then underwent cTESE following sperm seen on TCE was 97.1%. The SRR for 8 men who underwent mTESE after no sperm was found on TCE was 75%. The positive predictive value of TCE for successful TESE result is 94.4% for men with NOA. Treatment success rate of TCE and cTESE was 79.1% with a cost reduction of 59.4%.

CONCLUSION

TCE is a prognostic tool to guide decision making between cTESE and mTESE and maximize sperm retrieval rate while mitigating financial burden and operative complexity. TCE is important to identify ideal candidates for both procedures to maximize efficacy and safety amongst men with NOA.

Histological and immunohistochemical outcomes after microdissection TESE in contrast with hormonal profile, testis volume and genetics in patients with azoospermia

A limited number of individuals with non-obstructive azoospermia (NOA) may recover spermatozoa through traditional testicular sperm extraction (TESE) techniques. There is an ongoing debate over the effectiveness of microdissection TESE compared to standard TESE methods. Microdissection TESE (micro-TESE) techniques enable the identification of spermatogenesis foci in non-obstructive forms of azoospermia. Only histological examination can provide an objective and definitive assessment of the testicular phenotype. This study aimed to evaluate the correlation between histopathological findings after microdissection TESE (micro-TESE) and the predictive role of various factors in determining the success of sperm retrieval. We evaluated 24 patients with azoospermia who underwent micro-TESE and considered the patient's hormonal profile, testis ultrasound, genetic evaluation, histology, and immunohistology (PLAP antibody) of collected testis biopsies. The preoperative blood FSH level, in conjunction with other parameters, may aid in the prediction of micro-TESE success. Sensitivity increases, and specificity decreases with higher FSH levels. Furthermore, testicular volume and FSH levels are typically normal in patients with maturation arrest. In conclusion, hormones, ultrasound evaluation of the testicles, testis volume, and available genetic tests have a predictive value in differentiating obstructive azoospermia (OA) from NOA with various sensitivity and specificity rates. Histological and immunohistochemical evaluation establishes the testicular phenotype accurately and guides patient management.

Development and validation predictive models of sperm retrieval for azoospermic men undergoing testicular sperm aspiration: a multicentre, retrospective, cohort study

PURPOSE

Testicular sperm aspiration (TESA) is widely used to retrieve sperm from testis. Diagnostic testicular biopsy should not be routinely performed for azoospermia. Therefore, a good predictive model is needed before TESA.

METHODS

A total of 1972 azoospermia patients constituted the modelling set, and 260 azoospermia patients from two other centres constituted the validation set. An integrated predictive model was built using logistic regression. Receiver operating characteristic (ROC), calibration and decision curve analyses were performed to evaluate the performance of follicle-stimulating hormone (FSH), semen volume, testicular volume and the integrated model.

RESULTS

The FSH level was the best univariate predictor for successful sperm retrieval (SSR) and was better than semen volume and testicular volume alone (p<0.001, threshold 6.17 IU/L, modelling set area under receiver operating characteristic curve (AUC) 0.80, accuracy 0.79; validation set AUC 0.87, accuracy 0.78). The integrated predictive model had excellent accuracy for predicting SSR (modelling set: AUC 0.93, accuracy 0.89; validation set: AUC 0.96, accuracy: 0.89). Calibration curve analysis indicated that the integrated model calibration was good and better than that of FSH, semen volume and testicular volume alone. Decision curve analysis indicated with a threshold probability between 0.05 and 0.98, the integrated model added more benefit than treating either all or no patients.

CONCLUSIONS

The integrated model has excellent discrimination and good calibration. It can help azoospermic men make better decisions before TESA. It should be noted that TESA is not the first-line treatment for non-obstructive azoospermia because of a low sperm retrieval rate.

Comparative Clinical Study of Percutaneous Epididymal Sperm Aspiration and Testicular Biopsy in the Outcome of ICSI-Assisted Fertility Treatment in Patients with Obstructive Azoospermia

Objective

To compare and contrast the effects of percutaneous epididymal sperm aspiration (PESA) and testicular sperm aspiration (TESA) on the outcome of intracytoplasmic sperm injection (ICSI)-assisted fertility treatment in patients with obstructive azoospermia.

Methods

Patients with obstructive azoospermia with an age distribution of 20–36 years admitted to the male department of the Reproductive Center of the Second Affiliated Hospital of South China University (Hengyang Nanhua Xing Hui Reproductive Health Hospital) from December 2018 to December 2020 were used in this study. One group was set up as the PESA group to perform PESA, and the other group was set up as the TESA group to perform percutaneous testicular biopsy for sperm extraction. Patients who were unsuccessful in PESA continued to undergo TESA, and if sperm were retrieved, they were classified as the TESA group. General information on male patients and their partners was collected and compared in patients from different sperm source groups. Embryo development (normal fertilization rate, high-quality embryo rate, and high-quality blastocyst rate) and pregnancy outcome (clinical pregnancy rate, miscarriage rate, and ectopic pregnancy rate) were compared between the two groups.

Results

Finally, there were 26 patients in the PESA group and 31 patients in the TESA group. There were no significant differences in terms of age, years of infertility, testosterone level, (FSH) follicle-stimulating hormone level, and testicular volume between the male patients in the PESA and TESA groups of two different sperm sources, and no significant differences were found in the general conditions of the female patients in terms of age, number of eggs obtained, number of sinus follicles, basal FSH value, and basal E2 value (p > 0.05). The rate of high-quality blastocysts in the TESA group was significantly higher than that in the PESA group (p < 0.05); the differences in clinical normal fertilization rate, high-quality embryo rate, clinical pregnancy rate, miscarriage rate, and ectopic pregnancy rate between the two groups were not statistically significant (p > 0.05).

Conclusion

ICSI with different sources of sperm in patients with male factor infertility alone, which had no significant effect on embryo development, embryo implantation rate, clinical pregnancy rate, and miscarriage rate, resulting in better clinical outcomes.

Potential of testis-derived circular RNAs in seminal plasma to predict the outcome of microdissection testicular sperm extraction in patients with idiopathic non-obstructive azoospermia

STUDY QUESTION

Do testis-derived circular RNAs (circRNAs) in seminal plasma have potential as biomarkers to predict the outcome of microdissection testicular sperm extraction (micro-TESE) in patients with idiopathic non-obstructive azoospermia (NOA)?

SUMMARY ANSWER

Testis-derived circRNAs in the seminal plasma can indeed be used for predicting the outcome of micro-TESE in patients with idiopathic NOA.

WHAT IS KNOWN ALREADY

Micro-TESE is an effective method to obtain sperm samples from patients with idiopathic NOA. However, its success rate is only 40-50% in such patients.

STUDY DESIGN, SIZE, DURATION

Six idiopathic NOA patients with different micro-TESE results were included as the discovery cohort. Their testicular tissues were used for extracting and sequencing circRNAs. Five circRNAs with the most significantly different expression levels were selected for further verification.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fifty-two patients with idiopathic NOA were included as the validation cohort. Preoperative seminal plasma samples of 52 patients with idiopathic NOA and 25 intraoperative testicular tissues were collected and divided into 'success' and 'failure' groups according to the results of micro-TESE. Quantitative real-time polymerase chain reaction was performed to verify differences in the expression levels of the selected circRNAs between the two groups in the testicular tissues and seminal plasma.

MAIN RESULTS AND THE ROLE OF CHANCE

Whether at the seminal plasma or testicular tissue level, the differences in the expression levels of the three circRNAs (hsa_circ_0000277, hsa_circ_0060394 and hsa_circ_0007773) between the success and failure groups were consistent with the sequencing results. A diagnostic receiver operating curve (ROC) analysis of the AUC indicated excellent diagnostic performance of these circRNAs in seminal plasma in predicting the outcome of micro-TESE (AUC values: 0.920, 0.928 and 0.891, respectively). On the basis of least absolute shrinkage and selection operator (LASSO) logistic regression, the three circRNAs were combined to construct a new prediction model. The diagnostic ROC curve analysis of the model showed an AUC value of 0.958. The expression levels of these circRNAs in seminal plasma using three normospermic volunteer samples remained stable after 48 h at room temperature.

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

This was a single-center retrospective study with relatively few cases. The functions of these circRNAs, as well as their relationship with spermatogenesis, have not yet been established.

WIDER IMPLICATIONS OF THE FINDINGS

Testis-derived circRNAs in seminal plasma can reflect the microenvironment of the testis and can be used as reliable biomarkers to screen patients with idiopathic NOA who might be suitable for micro-TESE.

STUDY FUNDING/COMPETING INTEREST(S)

This article was funded by the National Natural Science Foundation of China (Grant no. 81871151). There were no competing interests.

Hormonal markers as noninvasive predictors of sperm retrieval in non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is one of the leading causes of male factor infertility, which results from impaired spermatogenesis. Currently, the sole feasible therapeutic option for men with NOA to father their biologic children is sperm retrieval by testicular sperm extraction (TESE) approaches followed by an intracytoplasmic sperm injection program. Nevertheless, the rate of sperm retrieval from NOA men following TESE has remained as low as 50%, leading to a significant number of unsuccessful TESE operations. Given that TESE is associated with multiple side effects, the prediction of TESE outcome preoperatively can abolish unnecessary operations and thereby prevent NOA patients from sustaining adverse side effects. As the process of spermatogenesis is under the regulation of hormones, the hormonal profile of serum and/or seminal plasma may contain useful information about spermatogenesis status and can potentially predict the chance of sperm retrieval from NOA patients. A large body of literature is available on the predictive capability of different serum and seminal plasma hormones such as FSH, LH, testosterone, inhibin B, AMH, estradiol, prolactin, and leptin in a stand-alone basis or combinational fashion with respect to the TESE outcome. The present review aimed to evaluate the potential of these hormonal markers as noninvasive predictors of sperm retrieval in men with NOA.

Differential Diagnosis of Azoospermia in Men with Infertility

The differential diagnosis between obstructive and nonobstructive azoospermia is the first step in the clinical management of azoospermic patients with infertility. It includes a detailed medical history and physical examination, semen analysis, hormonal assessment, genetic tests, and imaging studies. A testicular biopsy is reserved for the cases of doubt, mainly in patients whose history, physical examination, and endocrine analysis are inconclusive. The latter should be combined with sperm extraction for possible sperm cryopreservation. We present a detailed analysis on how to make the azoospermia differential diagnosis and discuss three clinical cases where the differential diagnosis was challenging. A coordinated effort involving reproductive urologists/andrologists, geneticists, pathologists, and embryologists will offer the best diagnostic path for men with azoospermia.