Factors determining the sperm retrieval rate in fresh versus salvage micro-TESE: a comparative cohort study

Role of Follicle-stimulating Hormone, Inhibin B, and Anti-Müllerian Hormone in Predicting Sperm Retrieval from Men with Nonobstructive Azoospermia Undergoing Microdissection Testicular Sperm Extraction: A Systematic Review and Meta-analysis

Background and objective

No clear-cut markers for predicting positive sperm retrieval (+SR) at microdissection testicular sperm extraction (mTESE) have been identified thus far. Our aim was to conduct a systematic review and meta-analysis to evaluate the ability of follicle-stimulating hormone (FSH), inhibin B (InhB), and anti-Müllerian hormone (AMH) to predict +SR in men with nonobstructive azoospermia (NOA) undergoing mTESE.

Methods

We performed a search in the PubMed, EMBASE, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Thirty-four publications were selected for inclusion in the analysis.

Key findings and limitations

Overall, the mean +SR rate was 45%. Pooled standardized mean difference (SMD) values revealed significant hormonal differences between the +SR and -SR groups, with lower FSH (SMD -0.30), higher InhB (SMD 0.54), and lower AMH (SMD -0.56) levels in the +SR group. Pooled odds ratios (Ors) revealed no significant prediction of +SR by either FSH (OR 1.03, 95% confidence interval [CI] 1.00-1.06) or InhB (OR 1.01, 95% CI 1.00-1.02), despite variations in baseline levels and study heterogeneity. Conversely, AMH had significant predictive value (OR 0.82, 95% CI 0.73-0.92), with lower baseline levels in the +SR group. InhB and FSH levels were higher in the +SR group, while InhB exhibited the opposite trend.

Conclusions and clinical implications

Despite study heterogeneity, our meta-analysis findings support the ability of AMH to predict +SR for men with NOA undergoing mTESE.

Patient summary

We conducted a review and analysis of results from previous studies. Our findings show that for men with an infertility condition called nonobstructive azoospermia, blood levels of anti-Müllerian hormone can predict successful extraction of sperm using a microsurgical technique. Levels of two other hormones did not predict successful sperm extraction.

Parameters affecting the success rate of microscopic testicular sperm extraction in male patients with a solitary testis and non-obstructive azoospermia

PURPOSE

We aimed to compare the success rate of spermatozoa retrieval through microscopic testicular sperm extraction (mTESE) in non-obstructive azoospermic (NOA) men with a solitary testis with that of mTESE in NOA men with bilateral testes and the parameters affecting these rates.

METHODS

A retrospective cross-sectional study of factors contributing to infertility in NOA patients with a solitary testis and men with bilateral testes was carried out. In this multicenter study, 74 patients with NOA with a solitary testis were matched with 74 patients with bilateral testes in terms of age, duration of infertility, and volume of the solitary testis from 2770 patients with NOA with bilateral testes. Hormonal parameters, presence of varicocele, history of varicocelectomy, history of undescended testis and karyotype analysis results were compared.

RESULTS

Spermatozoa were obtained from 40 (54.1%) patients with a solitary testis and 42 (56.76%) patients with bilateral testes. No differences were found regarding age, duration of infertility, or mean testicular volume between patients with a solitary testis and patients with bilateral testes. When serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were compared regardless of sperm retrieval status, it was observed that both levels were greater in the group of patients with a solitary testis (p < 0.01). Patients with solitary and bilateral testes from whom spermatozoa were obtained had larger testes than those from whom spermatozoa could not be obtained (p < 0.05). Similarly, the serum levels of FSH and LH were significantly greater in patients with a solitary testis than in those with bilateral testes (p < 0.05).

CONCLUSIONS

To the best of our knowledge, this is the first study in the literature to evaluate the parameters that influence mTESE outcome in NOA patients with a solitary testis and NOA patients with bilateral testes. Greater testicular volume was found to positively affect spermatozoa retrieval for patients with a solitary testis. The higher levels of FSH and LH in patients with a solitary testis than in patients with bilateral testes of similar testicular volume may be due to a compensatory mechanism developed by the hypothalamic-pituitary-gonadal axis. The fact that these hormones are higher in patients with a solitary testis does not mean that the number of spermatozoa obtained through mTESE will be decreased.

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.

Varicoceles in Men With Non-obstructive Azoospermia: The Dilemma to Operate or Not

The knowledge on male reproduction is constantly expanding, especially in treating infertility due to non-obstructive azoospermia (NOA). Varicocele is occasionally diagnosed in a subpopulation of males with NOA. Varicocele repair in NOA-men may contribute to the reappearance of spermatozoa in semen. However, spontaneous pregnancies are observed in only a small percentage of NOA-men post-varicocelectomy. Additionally, it has been reported that the repair of varicocele in NOA-men (before the performance of sperm retrieval techniques) may increase the testicular sperm recovery rate. In addition, it increases the pregnancy rate in intracytoplasmic sperm injection (ICSI) programs in NOA-men without spermatozoa in the semen post-varicocelectomy. In addition, to the improvement in Sertoli cellular secretory function, varicocelectomy may increase the secretory function of Leydig cells, which subsequently results in improved androgen production, raising the probability to negate the need for testosterone replacement therapy in cases of late-onset hypogonadism. On the other hand, the benefit of varicocelectomy in patients with NOA is still debatable. The current review study aims to provide a critical and extensive review of varicocele repair in males with NOA. This study additionally focuses on the impact of varicocele repair on sperm retrieval rates and its influence on the ICSI outcomes for those couples who remain negative for spermatozoa in their semen samples post-varicocelectomy.

Success rate and ART outcome of microsurgical sperm extraction in non obstructive azoospermia: A retrospective study

Background

The management of non-obstructive azoospermia (NOA) disease relies on microdissection testicular sperm extraction (micro-TESE). Few studies have assessed the role of micro-TESE in men with NOA in our country.

Objective

The aim of the current study was to investigate the success rate of micro-TESE.

Materials and Methods

This retrospective descriptive-analytical study was conducted on 463 men with NOA in Yazd Reproductive Sciences Institute during September 2017 through September 2019. Sperm were retrieved and frozen according to the rapid sperm freezing protocol. After preparing the oocyte of the male partner's spouse, sperms were thawed and then entered the intracytoplasmic sperm injection process. The clinical pregnancy of individuals was confirmed via ultrasound. Demographic data were extracted from medical records.

Results

The success rate of micro-TESE was 38% and successful fertilization, biochemical pregnancy, clinical pregnancy, and live birth were observed in 111 (85.4%), 29 (22.3%), 29 (22.3%) and 14 (10.7%) men, respectively. A significant difference was seen between the two groups, regarding age (p = 0.01). In addition, the mean follicle-stimulating hormone in men with positive micro-TESE was significantly lower than in men with negative micro-TESE (p = 0.02).

Conclusion

The success of pregnancy in couples with NOA managed via micro-TESE was significant. The study found that the success rate of micro-TESE was higher in older men and in those with lower follicle-stimulating hormone levels.

Methylation patterns of methylenetetrahydrofolate reductase gene promoter in infertile males

Errors of folate/homocysteine pathways which are critical for transferring methyl groups have been suggested to affect male fertility. We aimed to evaluate the methylation patterns of the promoter of methylenetetrahydrofolate reductase (MTHFR) gene in infertile males and to investigate the association between MTHFR promoter methylation and success of sperm retrieval. Thirty-five nonobstructive azoospermic and 46 severe oligozoospermic patients constituted the study group and were compared with 49 fertile and/or normozoospermic men. The methylation status was analysed by methylation-specific polymerase chain reaction. MTHFR promoter methylation was detected in infertile men with NOA and SO in the ratio of 48.6% and 58.7%, respectively. Methylation was also observed in 51% of controls. MTHFR promoter was methylated in 65% of men with viable spermatozoon during TESE. No association was found regarding to the profile of MTHFR promoter methylation between both NOA and SO patients and controls (p = .621). There was no relation between the methylation status of MTHFR promoter and low motility and poor morphology (p = .682 and p = .413, respectively). No association was found between MTHFR promoter methylation and presence of viable spermatozoa (p = .382). Our data indicate that the promoter methylation of MTHFR gene may not be associated with male infertility.