[Sperm small non-coding RNAs and intergenerational inheritance].

Recent studies have confirmed that, in addition to sperm DNA, environmental exposure factors such as parental diet structure and stress state affect early embryonic development and offspring growth, thus leading to cross-generational inheritance of acquired traits. Many studies also show that environmental stressors can change the expression level of sperm small non-coding RNAs (sncRNAs). Furthermore, as the carrier of paternal genetic information transmission and epigenetic marker, sncRNAs are directly or indirectly involved in epigenetic regulation, mediating inter-generational inheritance of acquired traits. This review focuses on the two sncRNAs derived from microRNA (miRNA) and tRNA (tsRNA) in sperm epigenetics research.

Risks associated with cryopreserved semen in a human sperm bank during and after the COVID-19 pandemic.

RESEARCH QUESTION: What are the risks associated with cryopreserved semen collected during and after the coronavirus disease 2019 (COVID-19) pandemic wave in Wuhan, China? DESIGN: Retrospective cohort study involving young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank (China) during the pandemic wave (1 January 2020 to 30 January 2020) and after the wave and return to work (7 April 2020 to 30 May 30 2020). One hundred paired semen and blood specimens from 100 donors were included. One-step single-tube nested quantitative real-time polymerase chain reaction (OSN-qRT-PCR) was used to detect SARS-CoV-2. Moreover, to control the unacceptable risk of false-negative results, a second round of screening was performed with pooled RNA from negative semen samples using crystal digital PCR (cd-PCR). RESULTS: For individual blood and semen samples, the target genes, namely the nucleocapsid protein (N) and open reading frame (ORF-1ab) genes, tested negative in all of the 100 paired samples. Further, as per cd-PCR results, there were >20,000 droplets per well in the RNA for each combined sample and no positive droplets were present for either of the aforementioned target genes. A total of 100 paired semen and blood samples from these two groups tested negative for SARS-CoV-2. CONCLUSIONS: Cryopreserved semen at the Hunan Province Human Sperm Bank during and after the COVID-19 pandemic wave was free of SARS-CoV-2 and was judged safe for external use in the future.

Intra-Cytosplamic sperm injection outcomes with fresh and cryopreserved human epidydimal sperm from patients with obstructive azoospermia.

Techniques for the cryopreservation of epididymal sperm was are widely used in clinical practice. However, given the unique characteristics of sperm from patients with obstructive azoospermia, epididymal sperm cryopreservation is more difficult because of low count and weak motility; therefore, conventional methods of sperm cryopreservation may not result in the best outcomes. We used the micro-straw method to store small quantities of sperm obtained from patients with severe oligozoospermia or azoospermia and achieved successful deliveries in the previous study. This retrospective study of ICSI cycles included the first ICSI cycles of fresh or frozen/thawed epididymal sperm that were performed in patients suffering from obstructive azoospermia who were admitted to the CITIC-Xiangya Hospital of Reproduction and Genetics of China from June 1, 2015 to June 31, 2019. A total of 2441 patients with obstructive azoospermia were divided according to the use of fresh (n = 2342) or frozen/thawed (n = 99) epididymal sperm. The results showed that the fertilisation rate was higher with fresh epididymal sperm than that with frozen/thawed epididymal sperm (85.14% vs. 79.26%, respectively; p = 0.000). However, the rates of embryo cleavage, high-quality embryos, clinical pregnancy, miscarriage, singletons and birth defect were similar between fresh and frozen/thawed epididymal sperm (98.28% vs. 99.13%, 60.34% vs. 57.29%, 67.90% vs. 70.51%, 8.12% vs. 10.91%, 57.76% vs. 49.09%, 1.59% vs. 1.45%respectively; p = 0.088, 0.109, 0.628, 0.462,0.203 and 0.686). In addition, the short-term cryostorage of small quantities of epididymal sperm did not affect clinical outcomes. The results indicated that in cases of obstructive azoospermia, cryostorage of small quantities epididymal sperm is a reliable option.

Sperm donor lifestyle survey: modifiable risk factors for potential sperm donors.

OBJECTIVES: To examine the association between modifiable lifestyle factors and the main semen parameter values, the number of qualified sperm donors, and to provide some sensible guidance for sperm donors. METHODS: Healthy men screened as potential sperm donors were recruited in the Hunan Province Human Sperm Bank of China from March 2019 to December 2019. Participants were invited to complete interviewer-assisted questionnaires on eleven items of information. Univariate and multivariate analyses were conducted to analyze which lifestyle factors collected by the questionnaire had an impact on the eligibility and main semen parameters of sperm donors. RESULTS: The eligibility of men as sperm donors was strongly influenced by the duration of abstinence (P = 0.002). The rate of eligibility sperm donors increased significantly with the number of days of abstinence. In addition, semen volume increased with abstinence time (P = 0.000). Exercise frequency (P = 0.025) and abstinence time (P = 0.000) were positively correlated with sperm concentration, and masturbation frequency was negatively correlated with sperm concentration (P = 0.013). Progressive sperm motility was significantly affected by abstinence time (P = 0.000) and bedtime (P = 0.047). CONCLUSIONS: Abstinence time was highly associated with semen parameters and donor qualification. Increase the abstinence time before donation may be meaningful in improving the proportion of eligible sperm donors.

[Advances in researches on cryopreservation of testicular spermatozoa].

Infertility affects approximately 20% of childbearing couples in the world, and azoospermia accounts for 10－15% of the causes of male infertility. The use of fresh or frozen-thawed testicular sperm for intracytoplasmic sperm injection (ICSI) has become a main method for azoospermia patients to realize their dream for reproduction. However, testicular spermatozoa are not further matured in the epididymis and therefore have an obviously lower anti-freezing ability than ejaculated sperm. The viability and retrieval rate of sperm are low after freeze-thaw with the conventional method of cryopreservation. Since the first live birth with frozen-thawed testicular spermatozoa, continuous improvement has been made in the methods of testicular sperm cryopreservation and increased the viability and retrieval rate of spermatozoa after freeze-thaw. This review focuses on the methods of testicular sperm cryopreservation in the past 20 years to provide a theoretical basis for the development of assisted reproductive technology.

[Correlation of Mycoplasma genitalium infection with male infertility].

OBJECTIVE: To explore the correlation of Mycoplasma genitalium (MG) infection with male infertility. METHODS: Totally, 27 314 males with infertility and 200 fertile sperm donors underwent MG and routine seminal examinations. The infertile men were divided into azoospermia, oligozoospermia, asthenozoospermia, oligoasthenospermia, and normal semen quality groups based on the results of seminal examination, the 27 286 of them with age data into eight age groups (<21, 21－25, 26－30, 31－35, 36－40, 41－45, 46－50 and ≥51 years old), and the 9 058 with definite diagnosis into primary and secondary infertility groups. Fifty-six cases of MG infection among the infertile males were treated with antibiotics for 2 weeks and examined for changes of the semen parameters. RESULTS: Compared with the normal controls, the oligozoospermia patients showed a significantly higher rate of MG infection (0.50% vs 3.62%, P = 0.024), the highest in the ≥51 yr group (3.68%, P = 0.021), followed by the 21－25 yr group (3.00%, P = 0.048), and so did the infertile males (3.64%, P = 0.011), the men with primary infertility (3.73%, P = 0.010) and those with secondary infertility (3.57%, P = 0.015). MG infection was found to be associated with oligozoospermia (OR = 7.471, 95% CI: 1.001－55.784), primary infertility (OR = 7.704, 95% CI: 1.073－55.309) and secondary infertility (OR = 7.362, 95% CI: 1.026－52.837) but not with the age of the patients. Both sperm concentration and sperm count were significantly lower in the infected men before treatment than in the non-infection group after treatment (P < 0.05). CONCLUSIONS: MG infection is related to male infertility and reduces the semen volume and sperm concentration, but does not affect sperm motility.

[In vitro culture medium for sparse spermatozoa improves human sperm motility].

OBJECTIVE: To investigate whether in vitro culture medium (IVCM) for sparse spermatozoa can improve human sperm motility for the purpose of helping clinicians, laboratorians and patients choose a better strategy of assisted reproduction. METHODS: Semen samples were obtained from 178 males for routine semen examination from March to August 2016, including 151 cases of asthenozoospermia and 27 cases of normal sperm motility. A total of 200 µl was collected from each sample and divided into two equal portions and equal volumes of IVCM (experimental group) and F10 (1×) (control group) were added to the two portions, respectively, followed by 30-minute incubation at 37℃ in an incubator with 5% CO2. Sperm concentration, motility and viability and the percentages of progressively motile, non-progressively motile and immotile sperm were recorded before and after incubation. RESULTS: After activated with IVCM, neither the samples with asthenozoospermia nor those with normal sperm motility showed any statistically significant difference in sperm viability from the baseline or the control group (P>0.05). The rates of progressively and non-progressively motile sperm from the asthenozoospermia males were increased by 14.02% and 4.86% respectively, while that of immotile sperm decreased by 19.01% in the experimental group (P >0.01), and similar results were observed in the semen samples from the men with normal sperm motility. The percentage of reduced immotile viable sperm was positively correlated with that of immotile viable sperm in both the asthenozoospermia patients (r = 0.260, P <0.01) and the men with normal sperm motility (r = 0.679, P <0.01). CONCLUSIONS: IVCM can increase sperm motility without affecting sperm viability in men with either asthenozoospermia or normal sperm motility. The larger the proportion of immotile viable sperm, the higher the percentages of progressively and non-progressively motile sperm in the semen after IVCM activation, and this correlation is more significant in men with normal sperm motility than in asthenozoospermia patients.

[Safety of the offspring conceived by assisted reproductive technology with cryopreserved donor sperm].

OBJECTIVE: To investigate the pregnancy outcomes of assisted reproductive technology (ART) with cryopreserved donor sperm and the safety of the offspring thus conceived. METHODS: The Human Sperm Bank of CITIC Xiangya Hospital provided cryopreserved donor semen to 31 reproductive centers in China between January 2006 and December 2012, with which 50247 ART cycles were accomplished. We compared the rates of birth defects and spontaneous abortion of intracervical insemination (ICI), intrauterine insemination (IUI), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI). RESULTS: A total of 39 047 ART cycles were performed by artificial insemination with cryopreserved donor sperm, including 36 674 cycles of ICI and 2 372 cycles of IUI. Among the 8 612 clinical pregnancies achieved by ICI, there were 917 cases of spontaneous abortion (at <28 gestational wk) (10.6%) and 6133 live births, with 43 cases of birth defect (0.70%). Of the 547 clinical pregnancies achieved by IUI, there were 41 cases of spontaneous abortion (7.5%) and 426 live births, with 2 cases of birth defect (0.47%). Totally, 11 200 cycles of IVF and ICSI were accomplished with cryopreserved donor sperm. Of the 5 860 clinical pregnancies achieved by IVF, there were 456 cases of spontaneous abortion (7.8%) and 5089 live births, with 55 cases of birth defect (1.08%). Among the 350 clinical pregnancies achieved by ICSI, there were 30 cases of spontaneous abortion (8.6%) and 229 live births, with 3 cases of birth defect (1.31%). The birth defect rate of ART with cryopreserved donor sperm was significantly lower than that published by the Chinese Ministry of Health (0.86% vs 1.53%,P<0.01). CONCLUSIONS: The safety of the offspring conceived by ART with cryopreserved donor sperm is controllable.

Fertility preservation in adult male patients with cancer: a systematic review and meta-analysis.

STUDY QUESTION: Does sperm cryopreservation serve as a feasible and effective method for preserving fertility in adult male patients with cancer? SUMMARY ANSWER: Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer. WHAT IS KNOWN ALREADY: Sperm cryopreservation is the only way to efficiently preserve male fertility. It is an important procedure in ART. Recently, due to remarkable advances in cancer treatment, an increasing number of studies have reported the outcomes of sperm cryopreservation in patients with cancer. STUDY DESIGN SIZE DURATION: We conducted an extensive literature search for relevant studies published through to 31 December 2021, in the following databases: CENTRAL, CNKI, Cochrane Systematic Reviews, EMBASE, MEDLINE, PUBMED, and Web of Science. The search terms used were '(cryopreservation OR freeze OR freezing OR banking OR cryostorage OR storage) AND (sperm OR semen OR spermatozoon) AND (cancer OR tumor OR malignancy OR neoplasm)'. PARTICIPANTS/MATERIALS SETTING METHODS: We included all studies that reported offering or attempting to cryopreserve sperm before or during cancer treatment in male patients considered at risk of treatment-related fertility impairment. We evaluated the eligibility of all data in each study. The major exclusion criteria were as follows: non-cancer patients; pediatric and adolescent cancer patients; not reporting the use of cryopreserved sperm; use of fresh semen for ART; not reporting the number of patients with cancer offered sperm cryopreservation or attempting to do so before or during treatment; using an experimental fertility preservation technique such as preservation of testicular tissue or spermatogonial stem cells; duplicate data; abstracts, case report, comments, reviews, or editorials; insufficient data reported. The quality of the included studies was assessed using the Newcastle-Ottawa scale and the Methodological Index for Non-Randomized Studies. MAIN RESULTS AND THE ROLE OF CHANCE: This meta-analysis included 69 non-randomized studies, with 32 234 patients referred for sperm analysis and 23 178 patients cryopreserving at least one sperm sample. The pooled failed-to-cryopreserve rate was 10% (95% CI, 8-12%), and the sperm disposal and sperm use rates were 23% (95% CI, 16-30%) and 9% (95% CI, 8-10%), respectively. The pregnancy, miscarriage, and delivery rates were 28% (95% CI, 22-33%), 13% (95% CI, 10-17%), and 20% (95% CI, 15-25%), respectively. Subgroup analysis showed higher pregnancy and delivery rates, as well as a lower failed-to-cryopreserve rate, in recent studies compared to those released a decade ago. The studies from Asia reported higher sperm disposal and pregnancy rates than in other continents. Our analysis showed clinical pregnancy rates per cycle of 34% (27-41%), 24% (14-35%), and 9% (5-15%) and delivery rates per cycle of 23% (17-30%), 18% (11-26%), and 5% (1-9%) for ICSI, IVF, and IUI, respectively. LIMITATIONS REASONS FOR CAUTION: As with all meta-analyses, some limitations should be considered. The first limitation of our study is that the data span 36 years. During this time, the World Health Organization has revised its sperm analysis standards, and other important changes have been made. There is also a limitation in that the outcome does not analyze the correlation between the type of cancer and sperm quality. Many of the earlier studies were limited by small sample sizes and a lack of control groups. Furthermore, almost all studies did not consider the severity of the disease, which could potentially have a substantial impact on the results. Consequently, further research should evaluate the effect of the type of cancer and, in particular, the severity of the condition on sperm quality in order to draw more precise conclusions. Similarly, it is inappropriate that most studies failed to differentiate between patients with different types of tumors and instead drew generalized conclusions that are presumed to apply to all patients with cancer. In the present analysis, we did not have in-depth information on patients' disease, and although extensive efforts were made to conduct a thorough systematic review and meta-analysis of the outcomes for patients with various types of tumors, the results must be acknowledged as being subject to bias. However, the use of average results obtained in each study, without the patient-level data, might also represent a source of bias. WIDER IMPLICATIONS OF THE FINDINGS: Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer. The observed utilization rate of frozen sperm at 9% may underestimate the actual usage, as the short follow-up period is inadequate for obtaining comprehensive data on the use of frozen sperm in young cancer survivors. ART plays an important role in fertility preservation and the achievement of pregnancy, with this meta-analysis showing that ICSI delivers better clinical outcomes than IVF or IUI in patients with cancer undergoing fertility preservation. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Natural Science Foundation of China (grant no. 82001634, 81960550), and the China Postdoctoral Science Foundation (2019M661521). There are no competing interests to declare. REGISTRATION NUMBER: CRID 42022314460.

Long-term storage modifies the microRNA expression profile of cryopreserved human semen.

The global practice of cryopreservation of human semen is commonplace in Assisted Reproductive Technology (ART) labs and sperm banks. However, information on the effects of long-term cryopreservation on semen is limited to clinical data summaries and descriptions. For this study, we prepared 4 semen specimens of fresh semen, 4 specimens cryostored for at least 1 year, 3 specimens cryostored for at least 5 years, 4 specimens cryostored for at least 10 years, and 3 specimens cryostored for at least 15 years. Total RNA was extracted from each sample, amplified, labeled, and mapped to the known primary microRNA (miRNA) in the miRBase database, enabling the prediction of novel miRNAs. We found that cryopreservation can lead to changes in miRNA expression, and with the increase in storage time, these changes became more pronounced. Meanwhile, the expression of let-7d-3p, let-7c-5p and let-7i-3p miRNAs changed dynamically over cryostorage time in frozen-thawed human sperm. Furthermore, we analyzed the time-dependent dynamics of cryostorage-expressed miRNAs and their target mRNAs and found that half of the target genes were expressed in oocytes. These intersection genes were mainly enriched in cancer and cytoskeletal signaling pathways. Our findings showed that the miRNA expression profile of cryopreserved human semen is modified by long-term storage. Furthermore, as the storage time increases, the impact on human sperm becomes more pronounced in terms of miRNAs, which may have an effect on subsequent fertilization and embryonic development.

Exploring the impact of pericentric inversion of chromosome 9 on fertility in sperm donors.

ABSTRACT: Pericentric inversion of chromosome 9 (inv[9]) is a common chromosomal structural variant, but its impact on clinical outcomes remains debated. The screening criteria of sperm banks are rarely mentioned to individuals with inv(9). In this study, we evaluated the fertility of sperm donors with inv(9) who met eligibility criteria for sperm banks (inv[9]-eligible donors). From March 2004 to May 2022, chromosomal analysis of 16 124 sperm donors at CITIC-Xiangya Human Sperm Bank in Hunan Province (Changsha, China) found that 251 (1.6%) had chromosome variations, with inv(9) being the most prevalent at 1.1%. All 169 inv(9)-eligible donors were contacted to collect fertility outcome data, along with 206 eligible donors without inv(9) as controls. In addition, semen samples from inv(9)-eligible donors and eligible donors underwent assessments of sperm fluorescence in situ hybridization (FISH), mitochondrial membrane potential, DNA fragmentation index, acrosome integrity, reactive oxygen species (ROS), and sperm morphology. Results showed that inv(9) did not significantly increase reproductive risks overall. Despite detecting ROS level differences, the clinical impact may be insignificant. This study provides new data on the inv(9) population that can serve as a valuable reference for decision-making by sperm banks as well as for genetic counseling and clinical guidance for individuals carrying inv(9) variant.

Genetic testing of sperm donors in China: a survey of current practices.

Background: The National Health and Family Planning Commission of China (NHFPCC) issued the "Measures for the Management of Human Sperm Banks," which was revised in 2003 and is still in effect today. One of the standard guidelines is that potential donors undergo laboratory testing to exclude infectious and genetic diseases and karyotype analysis. However, patient demands for donor genetic testing have also increased, and only karyotype analysis to exclude genetic diseases is not sufficient to meet these demands. Objective: To examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Materials and methods: An electronic survey was distributed to twenty-seven sperm banks to examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Twenty-six human sperm banks responded to a 32-question survey about their current practices related to genetic testing of sperm donors. Results: The 26 sperm banks reported that all qualified sperm donors undergo karyotype analysis; 22 banks (84.6%) collected three generations of family history from each qualified sperm donor; 10 (38.5%) reported that they attempted to accommodate special requests from donor semen recipients for particular genetic tests. Only 2 of the 26 (7.7%) sperm banks reported that they performed whole-exome sequencing. At all the sperm banks, consent for genetic testing was obtained as part of the overall contract for sperm donors. Nineteen (73.1%) sperm banks had genetic counselors on their staff, while six (23.1%) had no genetic counselors on their staff but had access to genetic counselors at the hospital. Only one (3.8%) sperm bank had no genetic counselors on their staff or at the hospital. Conclusions: The need for larger scale genetic testing of donors and recipients and an extensive panel of genetic tests specific to the Chinese population. Additionally, professionally trained geneticists must be employed as genetic counsellors so that the results of genetic tests and their implications can be explained to donors.

Comparison of Clinical Outcomes, Risks, and Costs for 20,910 Donor In Vitro Fertilization and 16,850 Donor Artificial Insemination Treatment Cycles: A Retrospective Analysis in China.

PURPOSE: To evaluate the effectiveness of donor in vitro fertilization (IVF-D) and donor artificial insemination (AI-D) in clinical outcomes, risks, and costs. METHODS: This study analyzed the cycle changes and clinical outcomes in 20,910 IVF-D and 16,850 AI-D cycles between 2013 and 2021 in the Reproductive and Genetic Hospital of CITIC-Xiangya. A cost-effectiveness analysis was performed to evaluate the costs per couple and per live birth cycle in the two treatment groups. RESULTS: IVF-D had higher pregnancy and live birth rates than AI-D (p < 0.001). The cumulative pregnancy and live birth rates for three AI-D cycles were 41.01% and 32.42%, respectively, higher than the rates for one or two AI-D cycles. The multiple birth and birth defect rate of AI-D was lower than that of IVF-D significantly. IVF-D mean cost per couple was higher than that of AI-D (CNY32,575 vs. CNY11,062, p < 0.001), with a mean cost difference of CNY21,513 (95% confidence interval, CNY20,517-22,508). The mean costs per live birth cycle for IVF-D and AI-D were CNY49,411 and CNY31,246, respectively. CONCLUSION: AI-D is more cost-effective and poses a lower risk for infertility couples than IVF-D, and patients should undergo three AI-D cycles to obtain the highest success rate.

CBPH assay for the highest sensitive detection of SARS-COV-2 in the semen.

BACKGROUND: Great concerns have been raised on SARS-CoV-2 impact on men's andrological well-being, and many studies have attempted to determine whether SARS-CoV-2 is present in the semen and till now the data are unclear and somehow ambiguous. However, these studies used quantitative real-time (qRT) PCR, which is not sufficiently sensitive to detect nucleic acids in clinical samples with a low viral load. METHODS: The clinical performance of various nucleic acid detection methods (qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH) was assessed for SARS-CoV-2 using 236 clinical samples from laboratory-confirmed COVID-19 cases. Then, the presence of SARS-CoV-2 in the semen of 12 recovering patients was investigated using qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH in parallel using 24 paired semen, blood, throat swab, and urine samples. RESULTS: The sensitivity and specificity along with AUC of CBPH was markedly higher than the other 3methods. Although qRT-PCR, OSN-qRT-PCR and cdPCR detected no SARS-CoV-2 RNA in throat swab, blood, urine, and semen samples of the 12 patients, CBPH detected the presence of SARS-CoV-2 genome fragments in semen samples, but not in paired urine samples, of 3 of 12 patients. The existing SARS-CoV-2 genome fragments were metabolized over time. CONCLUSIONS: Both OSN-qRT-PCR and cdPCR had better performance than qRT-PCR, and CBPH had the highest diagnostic performance in detecting SARS-CoV-2, which contributed the most improvement to the determination of the critical value in gray area samples with low vrial load, which then provides a rational screening strategy for studying the clearance of coronavirus in the semen over time in patients recovering from COVID-19. Although the presence of SARS-CoV-2 fragments in the semen was demonstrated by CBPH, COVID-19 is unlikely to be sexually transmitted from male partners for at least 3 months after hospital discharge.

Update on techniques for cryopreservation of human spermatozoa.

In the 1960s, sperm cryopreservation was developed as a method to preserve fertility. Currently, techniques for the cryopreservation of human spermatozoa have been widely used in assisted reproduction. However, although sperm cryobiology has made notable achievements, the optimal method for the recovery of viable spermatozoa after cryopreservation remains elusive. Postthawing sperm quality can be affected by cryoprotectants, ice formation, storage conditions, and osmotic stress during the freezing process. This review discusses recent advances in different cryopreservation techniques, cryoprotectants, and freezing and thawing methods during cryopreservation and new indications for the use of cryopreserved spermatozoa.

Clinical benefit for cryopreservation of single human spermatozoa for ICSI: A systematic review and meta-analysis.

BACKGROUND: Systematic reviews have focused on sperm recovery and post-thaw parameters after cryopreservation, but there is no information on the associated clinical outcomes. In recent years, an increasing number of studies have reported cryopreservation of a single sperm due to the importance of fertility preservation. OBJECTIVES: To assess whether the cryopreservation of single human spermatozoa improves clinical outcomes in patients with azoospermia or severe oligospermia. MATERIALS AND METHODS: We conducted an extensive literature search using the following databases: CENTRAL, CNKI, Cochrane Systematic Reviews, EMBASE, MEDLINE, PUBMED, and Web of Science for relevant studies published through December 31, 2019. We calculated the pooled proportions of cryopreservation of a single human spermatozoon to assess the recovery, survival, fertilization, pregnancy, miscarriage, and delivery rates. Subgroup analyses were performed for the following covariates, (a) different carriers, (b) year of publication, and (c) source of sperm. RESULTS: We included 25 studies, which included 13 carriers. The pooled proportion of recovery rate of spermatozoa cryopreserved was 92% (95% CI, 87%-96%), and the survival, fertilization, pregnancy, miscarriage, and delivery rates were 76% (95% CI, 69%-83%), 63% (95% CI, 58%-67%), 57% (95% CI, 39%-74%), 12% (95% CI, 0%-33%), and 40% (95% CI, 12%-71%), respectively. Based on the subgroup analysis, the recovery and survival rates of frozen spermatozoa in a subgroup of different carriers were statistically significant. In the past decade, frozen single human spermatozoon technology has improved the recovery rates of frozen-thawed spermatozoa. However, the differences in clinical outcomes of frozen spermatozoa in subgroups of different sources of sperm were not statistically significant. DISCUSSION AND CONCLUSION: The techniques for single human spermatozoa are feasible and efficient and may benefit patients with severe oligospermia or azoospermia.

Evaluating an external quality assurance program for semen analysis in China during 2009-2020.

INTRODUCTION: Semen analysis (SA) plays a key role in guiding treatments of male reproductive diseases and infertility due to male factors; however, it remains challenging to conduct an accurate SA due to lack of standardization, highly subjective assessments, and problems with automated procedures. Therefore, quality assurance (QA) and teaching courses are essential for making the laboratory results more consistent. MATERIALS AND METHODS: The external quality assurance (EQA) scheme was organized by national human sperm bank technology training bases in Guangdong province in China between 2009 and 2020. Until 2020, 124 laboratories from China participated in the EQA program. The EQA scheme per year has been organized involving two semen aliquots for sperm concentration, two video recordings for motility, and two smears for sperm morphology. All samples used in the EQA scheme were obtained from different healthy donors or patients. RESULTS: We estimated that the median coefficient of variation (CV) of sperm concentration, ignoring the method used, was 26.6%. Using a 100 µm deep counting chamber led to a decreasing CV of 13.6%. For sperm motility, the median CV of nonprogressive motility was high (50.8%), but the CV of progressive motility (13.2%), immotile sperm (14.3%), and total motility (11.8%) were acceptable. The morphology assessment revealed large variability (44.4%) irrespective of the classification criteria. DISCUSSION: The reduction of interlaboratory variability is still a challenge during SA in China. Therefore, it is critical to increase awareness of joining EQA schemes and establish standardized training centers to follow WHO-recommended procedures toward Chinese standards.

Micro-straw: An efficient cryopreservation carrier for rare human spermatozoa.

BACKGROUND: Many cryopreservation carriers have been introduced to freeze rare human spermatozoa, however, these carriers relative attributes and comparative effectivenesses have not yet been systematically studied. OBJECTIVES: Is the micro-straw cryopreservation carrier more effective for cryopreserving rare human spermatozoa compared with the Cryoplus and a new micro-straw (LSL straw) carriers? MATERIALS AND METHODS: This study involves 93 samples from healthy sperm donors and 40 samples from patients diagnosed with oligospermia, asthenospermia, oligoasthenospermia, or obstructive azoospermia. We determined the optimal freeze-thaw protocol for the Micro-straw carrier. The post-thaw survival rate, normal sperm morphology, acrosome integrity, and DNA fragmentation for Micro-straw, Cryoplus, and LSL carriers were then determined. Finally, we verified the effects of freezing using these carriers by comparing the qualities of post-thaw spermatozoa from patients. RESULTS: The highest total motility (TM) and progressive motility (PR) survival rates were obtained by placing the Micro-straw at 1 cm above the LN2 surface for 70 s during freezing and in a 42°C water bath for 40 s during thawing. No differences were observed in the PR survival rate, acrosome integrity, and DNA fragmentation of the post-thaw spermatozoa from the three carriers. However, the normal morphology rate of spermatozoa frozen using the Micro-straw carrier was higher than for the Cryoplus carrier (p < 0.05), and the TM survival rate of spermatozoa frozen with the Micro-straw was higher than that for the LSL carrier (p < 0.01). In verification tests, there were no significant differences in the quality of post-thaw spermatozoa cryopreserved using these carriers for both rare spermatozoa or epididymal sperm. DISCUSSION AND CONCLUSION: Micro-straw, Cryoplus, and LSL carriers are all efficient means of freezing rare human spermatozoa. However, the Micro-straw carrier is more economical, safe, and user-friendly.

Genetic testing of sperm donors at a human sperm bank in China.

Background: In China, numerous human sperm banks only perform three-generation family history evaluation to exclude genetic diseases with clinical symptoms; therefore, many inherited risks cannot be detected before donor qualification even when a thorough genetic family history evaluation has been performed. Hence, the risk of recessive disease inheritance persists with the current eligibility guidelines in China regarding the donor selection process. Methods: Retrospective study that reviewed the genetic test analyses and clinical outcomes of young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank of China from January 1, 2018, to May 1, 2021. We included a total of 3231 qualified sperm donors: all donors underwent primary screening for thalassemia and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Whereafter, 278 of donors underwent genetic testing for specific genes, and 43 donors underwent whole exome sequencing. Results: 2.4% of 3231 qualified sperm donors might have thalassemia and 1.4% might have G6PD deficiency. Sperm donors with thalassemia and G6PD deficiency would be eliminated. Specific gene testing identified 7 of the 278 donors (2.5%) as carriers of at least one pathogenic or likely pathogenic variant in a gene, including 1.9% of 154 donors (3/154) as carrier variants in α-Like or ß-Like globin genes, 17.6% of 17 donors (3/17) as carrier variants in GJB2, 12.5% of 8 donors (1/8) as carrier variants in SMN1. In addition, among the 43 sperm donors carrying the 111 pathogenic/likely pathogenic variants, eight (18.6%) were carriers of pathogenic variants of the GJB2 gene. The frequency, therefore, was approximately 1 in 5. Conclusions: The data suggest that used blood routine and RDT can make a preliminary screening of sperm donors, and special gene testing should be performed for sperm donors according to the regional incidence of specific genetic diseases. Meanwhile, whole exome sequencing can be used as a supplementary application in sperm donor genetic testing, and aid a successful and healthy pregnancy. However, industry guidelines must be modified to incorporate its use.

Influence of sperm morphology on pregnancy outcome and offspring in in vitro fertilization and intracytoplasmic sperm injection: a matched case-control study.

Sperm morphology was once believed as one of the most predictive indicators of pregnancy outcome in assisted reproductive technology (ART). However, the impact of teratozoospermia on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes and its offspring remains inconclusive. In order to evaluate the influence of teratozoospermia on pregnancy outcome and newborn status after IVF and ICSI, a retrospective study was conducted. This was a matched case-control study that included 2202 IVF cycles and 2574 ICSI cycles and was conducted at the Reproductive and Genetic Hospital of CITIC-Xiangya in Changsha, China, from June 2013 to June 2018. Patients were divided into two groups based on sperm morphology: teratozoospermia and normal sperm group. The pregnancy outcome and newborn outcome were analyzed. The results indicated that couples with teratozoospermia had a significantly lower optimal embryo rate compared to those with normal sperm morphology in IVF (P = 0.007), while there were no statistically significant differences between the two groups in terms of the fertilization rate, cleavage rate, implantation rate, and pregnancy rate (all P > 0.05). Additionally, teratozoospermia was associated with lower infant birth weight in multiple births after IVF. With regard to ICSI, there was no significant difference in both pregnancy outcome and newborn outcome between the teratozoospermia and normal groups (both P > 0.05). Furthermore, no increase in the risk of birth defects occurred in the teratozoospermia group after IVF/ICSI. Consequently, we believe that teratozoospermia has limited predictive value for pregnancy outcomes in IVF/ICSI, and has little impact on the resulting offspring if multiple pregnancy is avoided.