Clinical outcomes of microdissection testicular sperm extraction and intracytoplasmic sperm injection in Japanese men with Y chromosome microdeletions

Sperm retrieval rate and patient factors in azoospermia factor c microdeletion azoospermia: a systematic review

OBJECTIVE

To reveal the overall sperm retrieval rate (SRR) and range in patients with azoospermia factor c (AZFc) microdeletion azoospermia by microdissection testicular sperm extraction (mTESE) and discuss the differences of preoperative patient factors among studies with various SRRs.

PATIENTS AND METHODS

We searched PubMed, Web of Science and Embase until February 2023. All studies reporting SRRs by mTESE and required parameters of patients with AZFc microdeletions were included. The primary outcome was the SRR and, if available, the pregnancy rate (PR) and live-birth rate (LBR) after intracytoplasmic sperm injection were also investigated as secondary outcomes.

RESULTS

Eventually 11 cohort studies were included in this review. A total number of 441 patients underwent mTESE and in 275 of them sperm was obtained, reaching an overall SRR of 62.4%. The SRRs among studies had a wide range from 25.0% to 85.7%. The studies reporting higher SRRs generally had older mean ages, and higher follicle-stimulating hormone and testosterone levels. Only four studies provided practical data on pregnancies and live-born children of patients with AZFc microdeletions, so the overall PR and LBR were unavailable.

CONCLUSIONS

The overall SRR of patients with AZFc microdeletion azoospermia was 62.4%. The effect of patient factors in SR needs further evidence in future work.

Azoospermia factor c microdeletions and outcomes of assisted reproductive technology: a systematic review and meta-analysis

OBJECTIVE

To investigate whether Azoospermia Factor c (AZFc) microdeletions affect Assisted Reproductive Technology (ART) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile men with and without AZFc microdeletions.

INTERVENTION(S)

Electronic databases were searched for case-control studies reporting sperm retrieval rates and outcomes of ART in infertile men with and without AZFc microdeletions from inception to April 2023. Study quality was assessed using the Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for both categories of infertile men.

MAIN OUTCOME MEASURES

The primary outcome was successful sperm retrieval and the secondary outcomes were outcomes of ART.

RESULTS

Case-control studies reporting sperm retrieval rates and ART outcomes in men with AZFa and AZFb deletions were unavailable. On the basis of the data from 3,807 men, sperm retrieval rates were found to be higher in men with AZFc microdeletions compared to their non-deleted counterparts [OR = 1.82, 95% CI 0.97, 3.41], but the difference was not statistically significant. A significantly lower fertilization rate (OR = 0.61, 95% CI [0.50, 0.74]), clinical pregnancy rate (OR = 0.61, 95% CI [0.42, 0.89]), and live birth rate (OR = 0.54, 95% CI [0.40, 0.72]) were observed in men with AZFc deletions compared with men without deletions. There was no statistically significant difference in rates of embryo cleavage, blastocyst formation, good-quality embryos, implantation, and miscarriage between the two groups. On correcting for female factors, the fertilization rate (OR = 0.76, 95% CI [0.71, 0.82]), cleavage rate (OR = 0.54, 95% CI [0.41, 0.72]), clinical pregnancy rate (OR = 0.39, 95% CI [0.30, 0.52]), and live birth rate (OR = 0.48, 95% CI [0.35, 0.65]) were significantly lower in men with AZFc deletions compared with controls.

CONCLUSIONS

Presence of AZFc microdeletions adversely affects outcomes of ART in infertile men. Further in-depth studies delineating the role of the AZF genes in embryonic development are necessary to understand the full-impact of this finding.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42022311738.

Very severe oligozoospermia with AZFc microdeletion patients may affect intracytoplasmic sperm injection clinical outcomes: A propensity score matching analysis

Purpose

To explore whether spermatozoa from AZFc microdeletion patients affect their outcomes of intracytoplasmic sperm injection (ICSI).

Methods

Eighty-five patients with AZFc microdeletion were recruited. A control group of one hundred and forty patients with severe oligozoospermia but without AZF microdeletion was selected using propensity score matching analysis with a 1:2 nearest neighbor algorithm ratio. The ICSI outcomes of the two groups were compared.

Results

AZFc microdeletion had lower rates of normal fertilization (73% vs. 80%, p = 0.17) and high-quality embryos (44% vs. 58%, p = 0.07) than the control group. There was no significant difference in the clinical pregnancy rate, miscarriage rate, and live birth rate between the two groups. When the sperm concentration was <1 million/mL, the AZFc microdeletion group exhibited lower rates of fertilization (71% vs. 80%, p = 0.03), high-quality embryo (44% vs. 58%, p = 0.02), clinical pregnancy (57% vs. 76%, p = 0.02), and live birth (49% vs. 72%, p = 0.01) than the control group. However, if sperm concentration was ≥1 million/mL, no significant differences were found.

Conclusion

If the sperm concentration is <1 million/mL, AZFc microdeletion do have a detrimental effect on most outcomes of ICSI.

Y chromosome microdeletions in Chinese men with infertility: prevalence, phenotypes, and intracytoplasmic sperm injection outcomes

BACKGROUND

The incidence of Y chromosome microdeletions varies among men with infertility across regions and ethnicities worldwide. However, comprehensive epidemiological studies on Y chromosome microdeletions in Chinese men with infertility are lacking. We aimed to investigate Y chromosome microdeletions prevalence among Chinese men with infertility and its correlation with intracytoplasmic sperm injection (ICSI) outcomes.

METHODS

This single-center retrospective study included 4,714 men with infertility who were evaluated at the Reproductive Center of the First Affiliated Hospital of Sun Yat-sen University between May 2017 and January 2021. Semen analysis and Y-chromosome microdeletion via multiplex polymerase chain reaction were conducted on the men. The study compared outcomes of 36 ICSI cycles from couples with male azoospermia factor (AZF)cd deletions with those of a control group, which included 72 ICSI cycles from couples without male Y chromosome microdeletions, during the same period. Both groups underwent ICSI treatment using ejaculated sperm.

RESULTS

Among 4,714 Chinese men with infertility, 3.31% had Y chromosome microdeletions. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the prevalent pattern of Y chromosome microdeletion, with 3.05% detection rate. The detection rates of AZF deletions in patients with normal total sperm count, mild oligozoospermia, severe oligozoospermia, cryptozoospermia, and azoospermia were 0.17%, 1.13%, 5.53%, 71.43%, and 7.54%, respectively. Compared with the control group, the AZFcd deletion group exhibited no significant difference in the laboratory results or pregnancy outcomes of ICSI cycles using ejaculated sperm.

CONCLUSIONS

This is the largest epidemiological study on Y chromosome microdeletions in Chinese men with infertility. The study results underline the necessity for detecting Y chromosome microdeletion in men with infertility and severe sperm count abnormalities, especially those with cryptozoospermia. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the most prevalent Y chromosome microdeletion pattern. Among patients with AZFcd deletion and ejaculated sperm, ICSI treatment can result in pregnancy outcomes, similar to those without AZFcd deletion.

Double strand DNA breaks in sperm: the bad guy in the crowd

PURPOSE

The main objective of this opinion paper was to bring to light and enhance our understanding of the amount of double-strand DNA breaks in sperm and whether there is a threshold of no return when considering repair by the oocyte/embryo.

METHODS

A brief review of literature related to the theories proposed for the appearance of double-strand breaks in human spermatozoa. Further commentary regarding their detection, how oocytes or embryos may deal with them, and what are the consequences if they are not repaired. Finally, a strategy for dealing with patients who have higher levels of double-strand DNA breaks in sperm is proposed by reviewing and presenting data using testicular extracted sperm.

RESULTS

We propose a theory that a threshold may exist in the oocyte that allows either complete or partial DNA repair of impaired sperm. The closer that an embryo is exposed to the threshold, the more the effect on the ensuing embryo will fail to reach various milestones, including blastocyst stage, implantation, pregnancy loss, an adverse delivery outcome, or offspring health. We also present a summary of the role that testicular sperm extraction may play in improving outcomes for couples in which the male has a high double-strand DNA break level in his sperm.

CONCLUSIONS

Double-strand DNA breaks in sperm provide a greater stress on repair mechanisms and challenge the threshold of repair in oocytes. It is therefore imperative that we improve our understanding and diagnostic ability of sperm DNA, and in particular, how double-strand DNA breaks originate and how an oocyte or embryo is able to deal with them.

The predictive factors of successful sperm retrieval for men with Y chromosome AZFc microdeletion

PURPOSE

To identify key predictors for successful sperm retrieval in men with AZFc microdeletion.

METHODS

Totally, 71 infertile men with confirmed AZFc microdeletion were studied. For each patient, the endocrine profile including serum follicle stimulating hormone (FSH), luteinizing hormone, total testosterone, prolactin, and estradiol was recorded, along with intratesticular testosterone levels (ITT), age, and testicular size. The factors were further analyzed to determine the key predictors for successful sperm retrieval.

RESULTS

Of the 71 men with AZFc microdeletion, 52 (73.2%) were classified as having non-obstructive azoospermia (NOA), 7 (9.9%) as having cryptozoospermia, and 12 (15.8%) as having severe oligoasthenoteratozoospermia. Of the 52 men with azoospermia, 47 received microdissection testicular sperm retrieval, and sperm retrieval was successful in 35 of those cases (74.5%). A significantly lower serum FSH (p = 0.03) was found in those patients from whom sperm could be successfully retrieved. The area under the receiving operating characteristic curve for FSH was determined to be 0.721. Using an FSH cutoff point of 12.95 mIU/mL, the model for predicting successful sperm retrieval was found to have 51.4% sensitivity, 83.3% specificity, 90.0% positive predictive value, and 37.0% negative predictive value. ITT levels were obtained from 7 NOA patients, the mean ITT and the mean ITT/serum testosterone ratio was 1932.8 ng/ml and 567.2 in 6 men with successful sperm retrieval, whereas, in a patient with fail sperm retrieval, the levels were 2370 ng/ml and 393.0.

CONCLUSION

Men exhibiting AZFc microdeletion with discernible spermatogenesis from whom sperm was successfully retrieved by mTESE generally presented with relatively lower FSH levels.

Do follicle-stimulating hormone receptor polymorphisms in infertile men influence intracytoplasmic sperm injection outcomes? A prospective cohort study

The follicle-stimulating hormone (FSH) and its receptor regulate the quantity and quality of spermatozoa production. Several studies have analyzed the effect of single nucleotide polymorphisms (SNPs) in exon 10 of the FSH receptor (FSHR) on basic semen parameters without yet reaching a firm consensus. The aim of this study was to evaluate the effect of p.Thr307Ala and p.Asn680Ser polymorphisms in exon 10 of the FSHR gene, in infertile men, on intracytoplasmic sperm injection (ICSI) outcomes. This study was conducted between March 2019 and February 2020 on infertile couples undergoing ICSI at Al Hadi Laboratory and Medical Center, Lebanon. Couples with severe infertility factors that may impair gametogenesis/embryogenesis (e.g. advanced maternal age, premature ovarian failure, underwent gonadotoxic treatments, etc.) were excluded from the study. Semen and blood samples were collected from infertile men on the day of oocyte collection. Infertile men (n = 173) were screened for FSHR variants using polymerase chain reaction-restriction fragment length polymorphism. Moreover, fertilization rates, embryo quality, and pregnancy outcomes were evaluated. Higher sperm concentrations were found in the p.Thr307Ala group than the p.Thr307Thr (P < 0.01) and p.Ala307Ala (P < 0.05) groups. Furthermore, fertilization rate was significantly lower in the p.Ala307Ala genotype than in the p.Thr307Thr genotype (P < 0.05). We showed that FSHR variants in infertile men undergoing ICSI could affect sperm concentration, motility, and fertilization rates. Therefore, it will be important to confirm these results in further studies using a larger sample size.

Repetitive DNA Sequences in the Human Y Chromosome and Male Infertility

The male-specific Y chromosome, which is well known for its diverse and complex repetitive sequences, has different sizes, genome structures, contents and evolutionary trajectories from other chromosomes and is of great significance for testis development and function. The large number of repetitive sequences and palindrome structure of the Y chromosome play an important role in maintaining the stability of male sex determining genes, although they can also cause non-allelic homologous recombination within the chromosome. Deletion of certain Y chromosome sequences will lead to spermatogenesis disorders and male infertility. And Y chromosome genes are also involved in the occurrence of reproductive system cancers and can increase the susceptibility of other tumors. In addition, the Y chromosome has very special value in the personal identification and parentage testing of male-related cases in forensic medicine because of its unique paternal genetic characteristics. In view of the extremely high frequency and complexity of gene rearrangements and the limitations of sequencing technology, the analysis of Y chromosome sequences and the study of Y-gene function still have many unsolved problems. This article will introduce the structure and repetitive sequence of the Y chromosome, summarize the correlation between Y chromosome various sequence deletions and male infertility for understanding the repetitive sequence of Y chromosome more systematically, in order to provide research motivation for further explore of the molecules mechanism of Y-deletion and male infertility and theoretical foundations for the transformation of basic research into applications in clinical medicine and forensic medicine.

A systemic review and meta-analysis exploring the predictors of sperm retrieval in patients with non-obstructive azoospermia and chromosomal abnormalities

To identify the most prevalent chromosomal abnormalities in patients with non-obstructive azoospermia (NOA), consolidate their surgical sperm retrieval (SSR) rates and determine the significant predictors of positive SSR in this patient population. A systematic review and meta-analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Fifty-three studies including 2965 patients were identified through searching the PubMed database. Klinefelter Syndrome (KS) was the most prevalent chromosomal abnormality reported in 2239 cases (75.5%). Azoospermia factor c (AZFc) microdeletions were the second most common (18.6%), but men with these deletions had higher SSR rates than patients with KS (41.95% with AZFc vs. 38.63% with KS). When examining predictors of SSR in KS patients, younger age was a significant predictor of positive SSR in patients undergoing microsurgical testicular sperm extraction (micro-TESE). Higher testosterone was a favourable predictor in those undergoing micro-TESE and conventional TESE. Lower luteinizing hormone (LH) and follicular stimulating hormone (FSH) values were significantly associated with positive SSR with testicular sperm aspiration (TESA). No parameter predicted SSR rates in patients with AZFc microdeletions. Overall, genetic abnormalities have significant implications on SSR success in patients with NOA.

Reproductive Chances of Men with Azoospermia Due to Spermatogenic Dysfunction

Non-obstructive azoospermia (NOA), or lack of sperm in the ejaculate due to spermatogenic dysfunction, is the most severe form of infertility. Men with this form of infertility should be evaluated prior to treatment, as there are various underlying etiologies for NOA. While a significant proportion of NOA men have idiopathic spermatogenic dysfunction, known etiologies including genetic disorders, hormonal anomalies, structural abnormalities, chemotherapy or radiation treatment, infection and inflammation may substantively affect the prognosis for successful treatment. Despite the underlying etiology for NOA, most of these infertile men are candidates for surgical sperm retrieval and subsequent use in intracytoplasmic sperm injection (ICSI). In this review, we describe common etiologies of NOA and clinical outcomes following surgical sperm retrieval and ICSI.

Poor intracytoplasmic sperm injection outcome in infertile males with azoospermia factor c microdeletions

OBJECTIVE

To explore whether the presence of azoospermia factor c (AZFc) microdeletions adversely affects intracytoplasmic sperm injection (ICSI) outcome.

DESIGN

Retrospective cohort.

SETTING

University hospital.

PATIENT(S)

A total of 293 patients with azoospermia or severe oligozoospermia AZFc deletions underwent 345 ICSI cycles, and 363 idiopathic patients with normal Y chromosome underwent 462 ICSI cycles.

INTERVENTION(S)

Testicular sperm aspiration, microdissection testicular sperm extraction.

MAIN OUTCOME MEASURE(S)

The main clinical outcome parameters were cumulative clinical pregnancy rate, cumulative live birth delivery rate, and no embryo suitable for transfer cycle rate.

RESULT(S)

Compared with the control group, the AZFc deletion group exhibited poorer ICSI outcome, with significant differences between the 2 groups for cumulative clinical pregnancy rate (45.39% vs. 67.49%; odds ratio [OR], 2.843; 95% confidence interval [CI]), cumulative live birth delivery rate (35.15% vs. 53.44%; OR, 2.234; 95% CI), no embryo suitable for transfer cycle rate (15.07% vs. 8.23%; OR, 0.565; 95% CI), fertilization rate (46.80% vs. 53.37%; adjusted β, -0.074; 95% CI), implantation rate (28.63% vs. 31.26%; adjusted β, -0.075; 95% CI) separately. The poor ICSI outcome of the AZFc deletion group was related to AZFc microdeletions by linear and logistic regression analyses.

CONCLUSION(S)

AZFc microdeletions adversely affect ICSI outcome; patients with AZFc deletion should be informed that they have reduced opportunities to be biological fathers.