Clinical management of transgender and non-binary patients in the fertility preservation service: Current evidence.

Background: Transgender and non-binary individuals face unique challenges when it comes to fertility preservation (FP). Objective: Despite the growing prevalence of gender dysphoria (GD) and gender transitioning, there is a lack of clear guidelines and consensus on the management of these patients in the FP setting. Clinicians and institutions providing FP services should ensure that they are aware of the needs and circumstances of this underrepresented group of patients and offer them accurate and evidence-based information when counseling and tailoring their FP treatment. Materials and methods: For this scoping review, three major search engines were used. Including Embase, Epistemonikos, Google Scholar, MEDLINE and PubMed. Sources of grey literature were also explored (ResearchGate and Web of Science). The combination of only two keywords [transgender] AND [fertility preservation] was used up to May 2023. Results: The available evidence on clinical management and FP outcomes in transgender patients is limited and mainly originates from case reports or small case series. The main limitation of current FP services for transgender and non-binary individuals is the lack of scientific evidence regarding their care. Discussion: Overall, FP in transgender patients requires individualized and realistic plans, and psychological counseling should be offered. This review aims to provide the latest evidence coming from original studies to facilitate proper counseling and fertility management for these individuals. Conclusions: Inclusive health systems that provide comprehensive reproductive health care to transgender individuals can help them make informed decisions about FP and improve their quality of life. Future research is needed to establish more robust evidence-based guidelines for the management of transgender and non-binary individuals in the FP setting.

Non-used cryopreserved sperm among oncological patients: extra-long-term follow-up and analysis.

PURPOSE: To investigate factors influencing long-term utilization and disposal patterns of cryopreserved semen straws in oncological patients. METHODS: This retrospective study included all men who cryopreserved semen due to cancer between October 1993 and December 2021. To assess non-used cryopreserved sperm straws, we investigated the following parameters: cryopreserved semen and usage for fertility treatments versus disposal, summarized by total non-used cases. A Kaplan-Meier curve was used to describe last usage and disposal requests over a 15-year analysis. A Log-rank test was applied to compare between age and paternal status categories. RESULTS: The cohort consisted of 445 patients. Of these, 55 patients utilized thawed semen for fertility treatments, and 65 opted for disposals, leaving 325 patients who neither used nor disposed of their cryopreserved straws. Our findings revealed a distinct pattern based on age, with the youngest age group (< 25 years) exhibiting significantly lower utilization and disposal rates compared to older patient groups. Additionally, men without children exhibited significantly fewer disposal requests compared to fathers. The median cryopreserved straws were 10 (interquartile range, 6 to 17), while the median used straws were only 2 (interquartile range, 2 to 6). DISCUSSION: Our study brings attention to the additional and needless burden of preservation from both patient and preserved straw perspectives. Implementing a policy based on a cost-effective approach, incorporating time and straw limits, and considering demographic characteristics, could enhance efficiency and necessitate patient consent before preservation.

Seminal plasma microbiomes, sperm parameters, and cryopreservation in a healthy fertile population.

Background: Recent advances in microbiome research have revealed the presence of diverse microbial communities in human tissues previously thought to be sterile. The present study delves into the emerging field of seminal plasma microbiomics, examining the relationship between semen microbes and semen parameters and post-freezing tolerance. Methods: The study involved a cohort of healthy fertility males and microbial genome analysis using 16S rRNA to characterize the microbial diversity of seminal plasma. Microbial diversity analysis identified unique amplicon sequence variants (ASVs) and genera dominant in seminal plasma. Spearman's correlation coefficient was used to assess the relationship between flora and semen parameters. A paired t-test was used to compare the changes in microbiome expression in seminal plasma before and after cryo-resuscitation. Results: The relevant results show that the top five phyla in terms of abundance of seminal plasma microbiome were Firmicutes, Bacteroidota, Proteobacteria, Actinobacteriota, and Campylobacterota. Spearman correlation analysis highlighted the association between specific microbial species and semen parameters, between Porphyromonas_asaccharolytica and sperm concentration. Microbial changed significantly after cryo-resuscitation, affecting taxonomic units such as Campylobacter and Muribaculaceae, and KEGG enrichment analyses, suggesting that metabolic pathways are associated with sperm freezing. Eubacterium_coprostanoligenes and Eptoniphilus_duerdenii exhibited a potential impact, while Orynebacterium_tuberculostearicum demonstrated a positive correlation with the recovery rate of progressive motile sperm. Conclusion: The semen of normal fertile individuals contains a microflora component that is closely related to semen quality, including the sperm's ability to withstand freezing.

Effects of astaxanthin supplementation during vitrification and liquid nitrogen vapor freezing on motility, morphology, survival, reactive oxygen species (ROS), and DNA fragmentation of post-cryopreserved human sperm.

OBJECTIVE: To investigate the effect of astaxanthin supplementation in cryopreservation media on post-thawed sperm motility, viability, morphology, reactive oxygen species (ROS), and DNA fragmentation in two cryopreservation techniques using vitrification and liquid nitrogen vapor freezing. METHODS: Thirty normozoospermic semen samples were used in the study. Post-prepared semen samples were divided into 1) non-cryopreserved control, 2) and 3) vitrified without (V) and with astaxanthin 0.5 µM (V+ATX), 4) and 5) frozen in liquid nitrogen vapor without (L) and with astaxanthin 0.5 µM (L+ATX). RESULTS: Cryopreservation using vitrification and liquid nitrogen vapor freezing significantly decreased sperm motility and viability and increased ROS levels. However, no changes were seen in sperm morphology or DNA fragmentation. The addition of astaxanthin in cryopreservation media significantly increased post-thawed motility in both vitrification (77.6±8.9% vs. 69.0±9.5% in V+ATX and V) and vapor freezing (57.0±13.3% vs. 47.7±14.6% in L+ATX and L); it significantly increased sperm viability in vitrification (75.0±11.9% vs. 65.9±11.1% in V+ATX and V), and significantly decreased ROS level in both vitrification (4.7 (2.6-8.3) RLU/sec/106 vs. 10.6 (9.4-16.0) RLU/sec/106 in V+ATX and V) and vapor freezing (4.6 (3.3-10.5) RLU/sec/106 vs. 10.3 (7.9-18.6) RLU/ sec/106 in L+ATX and L). Astaxanthin supplementation in cryopreservation media did not affect sperm morphology or DNA fragmentation. CONCLUSIONS: Astaxanthin supplementation improved post-cryopreserved sperm motility, decreased ROS levels in both vitrification and liquid nitrogen vapor freezing and improved sperm viability only in the vitrification technique.

Therapeutic use of platelet-rich plasma for the treatment of male infertility.

Platelet-Rich Plasma (PRP) is a regenerative therapy that has gained interest in recent years, being the subject of various studies and applications. In the field of human reproduction specifically, there are growth factors (GFs) present in PRP that have shown an impact on sperm quality and function. The main objective of this article is to conduct a literature review on the use of PRP for the treatment of male infertility. To achieve this, a bibliographic search of articles and reviews in scientific journals about the possible use of PRP for the treatment of male factor published between 2018 and 2023 has been carried out. Nine publications were identified, proposing the application of PRP in the following areas: sperm cryopreservation, oxidative stress, culture of spermatogonial stem cells, and secretory azoospermia. According to the literature, supplementing the cryopreservation medium with PRP improves sperm parameters, and samples incubated with PRP show an increase in their antioxidant capacity. Finally, PRP can increase the proliferation and vitality of spermatogonial stem cells and sperm recovery in cases of non-obstructive azoospermia. PRP shows therapeutic potential in various aspects of the male factor. Further research with a larger sample size is needed to define both its protocols and its clinical efficacy.

Sperm Cryopreservation in Canaries to Protect Endangered Songbird Species: Comparison of Different Cryoprotectants.

Sperm cryopreservation is a rather complex process that needs to be adapted to wild and domestic bird species to ensure adequate efficiency. This study aimed to determine the usability of different cryoprotectants in the cryopreservation of Gloster canary sperm. For this purpose, sperm samples were collected from 12 2-year-old male Gloster canaries three times a week using cloacal massage for 4 weeks. After individual evaluation, sperm samples from the canaries were combined. Mixed sperm were divided into two groups in the study. Overall, 8% dimethyl sulfoxide (DMSO) and ethylene glycol (EG) were used as cryoprotectants. Sperm samples were drawn into straws after adding Dulbecco's Modified Eagle Medium (DMEM) extender with high glucose ratio and two different cryoprotectants in a 1:1 ratio and frozen to -80°C with liquid nitrogen vapour and then stored in liquid nitrogen at -196°C. Frozen-thawed semen samples were evaluated regarding motility, vitality, plasma membrane integrity (hypoosmotic swelling test [HOST]), density and abnormal spermatozoa rate. The highest motility value after freezing and thawing was determined in the EG group with 31.667% ± 4.773%. In addition, vitality, plasma membrane integrity and normal sperm morphology were statistically significantly higher in the EG-frozen group, whereas head and tail abnormality was low (p < 0.05). This study determined that a DMEM extender containing 8% EG was more advantageous than a DMEM containing DMSO regarding spermatological parameters and could be used for long-term storage of canary sperm.

Effects of nano-berberine and berberine loaded on green synthesized selenium nanoparticles on cryopreservation and in vitro fertilization of goat sperm.

After cryopreservation, reactive oxygen species (ROS) can damage sperm. Antioxidants are the primary defense against oxidative damage. Berberine is a bioactive alkaloid found in Berberis vulgaris, Curcuma longa, and Ergon grape, and is a potent antioxidant. Due to the negative effects of free radicals in oxidative stress processes, antioxidant chemicals are required to protect sperm. However, berberine has low bioavailability, making it less effective. Loading techniques on nanoparticles and nanotechnology can help overcome this limitation. Selenium nanoparticles were synthesized with barberry extract, and berberine was loaded on them. Berberine nanoparticles were then synthesized using anti-solvent precipitation with a syringe pump technique. The synthesis of nanoparticles was confirmed by EDX, UV-visible, FE-SEM, Zeta-Potential, and FTIR tests. In this experiment, we aim to investigate the impact of nano-berberine and berberine loaded on Se-NPs on goat sperm parameters after freeze-thawing. We assessed the generation of reactive oxygen species (ROS), in vitro fertility, and the subsequent embryo development of zygote with treated sperm after determining the optimal concentration of various chemicals on sperm parameters. The study found that all treatments had significant differences from the control group in terms of motility, viability, DNA and membrane integrity, ROS level, lipid peroxidation, in vitro fertility ability, and the capacity to develop inseminated oocytes (p < 0.05). The most significant outcomes were observed with berberine loaded on Se-NPs and the combination of selenium nanoparticles with berberine nanoparticles.

Piceatannol Protects Sperm from Cryopreservation Damage by Modulating the Keap1-Nrf2/ARE Signaling Pathway.

The purpose of this study was to explore the mechanism of action of Piceatannol (PIC) in attenuating oxidative damage to sperm during cryopreservation. Semen samples were collected and homogenized into six equal parts for freeze-thawing experiments. Four different concentrations of PIC were utilized as cryoprotectants during the freeze-thawing process, maintaing a semen to PIC ratio of 1:1, while sperm motility after freezing and thawing was analyzed using computer-assisted sperm analysis (CASA). Sperm plasma membrane integrity was assessed via the hypo-osmotic swelling (HOS) test. The levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) activities, long with the ability to scavenge sperm malondialdehyde (MDA), were examined in sperm following the addition of PIC. Quantitative real-time PCR (qRT-PCR) was performed to detect the expression levels of Keap1, Nrf2, GCLC, GCLM, and HMOX1 in sperm. The mechanism by which PIC protects sperm during cryopreservation from oxidative stress damage was further verified. Treatment with PIC at a dose of 5.0 µmol/L significantly improved both sperm motility and viability while effectively reducing ROS levels in frozen sperm. Additionally, the integrity of the sperm plasma membrane was significantly enhanced. Furthermore, the expression level of Keap1 was significantly reduced, whereas the expression levels of GCLC, GCLM, HMOX1, and Nrf2 were significantly increased (p < 0.05) after the addition of PIC. Notably, a significant attenuation of sperm motility and viability was observed in this treatment group when PIC treatment was accompanied by the addition of an Nrf2 inhibitor, resulting in a significant elevation of ROS levels. The finding that PIC modulates ROS in frozen sperm via the Keap1-Nrf2/ARE pathway thereby enhancing sperm viability levels after freezing and thawing provides a novel approach to optimize semen cryopreservation.

Evaluation of the effect of lecithin and nanolecithin in repairing membrane damage, maintaining membrane integrity, and improving human sperm function in the freezing-thawing process.

PURPOSE: Our study aimed to evaluate the effects of lecithin nanoparticles on sperm quality during cryopreservation. METHODS: In phase one, sperm-freezing media were prepared with lecithin concentrations (0.5%, 1%, and 2%) and lecithin nanoparticles of various sizes (50-100, 100-200, and ≥ 200 nm). Post-thaw, sperm motility, viability, mitochondrial membrane potential (MMP), lipid peroxidation (measured by malondialdehyde, MDA), and DNA fragmentation were evaluated. In phase two, the acrosomal reaction was assessed in the best and worst-performing groups from phase one. DiI labeling detected interactions between lecithin nanoparticles and the sperm membrane. Field emission scanning electron microscopy (FESEM) examined the sperm membrane's surface structure and lecithin binding sites. Atomic force microscopy (AFM) assessed height differences in the sperm surface layer in the best-performing group from phase one. RESULTS: The group treated with 1% lecithin nanoparticles (50-100 nm) showed significantly increased viability post-thaw compared to other groups, with reduced DNA fragmentation and MDA levels. While motility significantly decreased in all groups compared to before freezing levels, lower concentrations, and smaller particle sizes yielded better results. MMP also significantly decreased across all groups with no significant differences. The acrosomal reaction significantly decreased with 1% lecithin nanoparticles (50-100 nm) compared to the 2% (≥ 200 nm) group. DiI-labeled nanoparticles and FESEM revealed that lecithin nanoparticles primarily bound to and infiltrated the sperm membrane, particularly in the head and postacrosomal regions. CONCLUSIONS: Lecithin nanoparticles effectively bind to the sperm membrane, protecting it during the freeze-thaw process and improving sperm viability.

Coenzyme Q10 Improves the Post-Thaw Sperm Quality in Dwarf Surfclam Mulinia lateralis.

Previous studies have shown that post-thaw sperm performance is affected by multiple stressors during cryopreservation, such as those induced by physical, chemical, mechanical and physiological changes. One of these is the balance disturbance between the antioxidant defense system and reactive oxygen species (ROS) production. This study investigated whether this disturbance could be alleviated by the addition of different antioxidants to cryoprotective solution [8% dimethyl sulfoxide (DMSO) in 1 µm filtered seawater] optimized for the sperm in dwarf surf clam Mulinia lateralis, the model bivalve species used in many different types of studies. Results showed that the addition of 20 µM coenzyme Q10 (Q10) to 8% DMSO achieved a D-stage larval rate similar to that of the fresh control at a sperm-to-egg ratio at least 50% less than the 8% DMSO treatment alone. The addition of other antioxidants (glycine, melatonin and polyvinylpyrrolidone) did not have any positive effects. The improvement in post-thaw sperm quality by Q10 could be due to its ability to significantly decrease ROS production and lipid peroxidation and significantly increase the motility, plasma membrane integrity, mitochondrial membrane potential, acrosome integrity, DNA integrity and activities of catalase and glutatione. In this study, 37 fatty acids (FAs) were quantified in dwarf surf clam sperm, with 21 FAs being significantly impacted by the cryopreservation with 8% DMSO. Thirteen of these 21 FAs were changed due to the addition of 20 µM Q10 to 8% DMSO, with approximately half of them being improved significantly toward the levels of fresh control, while the remaining half extended further from the trends shown with 8% DMSO treatment. However, no significant difference was found in the percentage of each FA category sum and the ratio of unsaturated/saturated FAs between the two treated groups. In conclusion, the antioxidant Q10 has shown the potential to further improve the sperm cryopreservation technique in bivalves.

Comparative Analysis of the Effects of Magnesium Oxide Nanoparticles on Sperm Parameters in Fresh and Frozen Samples.

Background: Freezing is a crucial technique in reproductive science utilized for the preservation of sperm samples. However, the process of freezing and thawing sperm can result in detrimental effects on sperm quality. One of the major mechanisms underlying this decline in sperm quality is the generation of reactive oxygen species during the freeze process. The purpose of the current study was to investigate the effects of magnesium oxide nanoparticles on frozen sperm parameters. Methods: Semen samples were collected from 8 fertile men, aged 30 to 42 years, with normozoospermia, following 3 to 5 days of abstinence. The samples were divided into fresh (n=3), freeze (n=3), and control (n=2) groups. Three fresh experimental groups were only exposed to MgO NPs with concentrations of 5, 25, and 50 µg/ml and three freezing experimental groups were frozen after being treated with MgO NPs, thawed, and analyzed after 30 min. Results: Our findings revealed that the progressive movement and vitality of sperm experienced a significant decline, while non-progressive and immotile sperm showed a notable increase in both fresh and frozen experimental groups exposed to MgO NPs. However, the application of MgO NPs during fresh and freezing processes demonstrated an effective preservation of pH, morphology, and DNA fragmentation in sperm cells. Conclusion: The analysis revealed that MgO NPs negatively impact sperm motility and viability in both fresh and freeze analysis. Also, the use of MgO NPs in fresh and frozen processes effectively maintains the pH, morphology, and fragmentation of DNA in sperm cells.

Effect of Supplementation of a Cryopreservation Extender with Pectoliv30 on Post-Thawing Semen Quality Parameters in Rooster Species.

Sperm cryopreservation is a fundamental tool for the conservation of avian genetic resources; however, avian spermatozoa are susceptible to this process. To cope with the high production of reactive oxygen species (ROS), the addition of exogenous antioxidants is beneficial. Pectoliv30 is a substance derived from alperujo, and in this study, its effect was analyzed on seminal quality after its addition to the cryopreservation extender of roosters at different concentrations. For this purpose, 16 Utrerana breed roosters were used, and seminal collection was performed in six replicates, creating a pool for each working day with ejaculates of quality. After cryopreservation, one sample per treatment and replicate was thawed, and several seminal quality parameters were evaluated. Statistical analysis revealed numerous correlations between these variables, both positive and negative according to the correlation matrix obtained. Furthermore, the chi-squared automatic interaction detection (CHAID) decision tree (DT) reported significant differences in the hypo-osmotic swelling test (HOST) variable between groups. Moreover, results for this parameter were more desirable at high concentrations of Pectoliv30. The application of this substance extracted from the by-product alperujo as an antioxidant allows the improvement of the post-thawing seminal quality in roosters and facilitates optimization of the cryopreservation process as a way to improve the conservation programs of different endangered poultry breeds.

Sperm Quality in 1252 Adolescents and Young Adults (AYAs) Undergoing Fertility Preservation Due to Cancer or Nonmalignant Diseases.

Purpose: To investigate the quality of emergency-collected semen samples aimed at sperm cryopreservation provided by adolescents and young adults (AYAs) presenting with cancer or nonmalignant diseases. Methods: This is a prospective cohort study of postpubertal males referred for sperm cryopreservation who provided at least one semen sample for fertility preservation at the Reproductive Medicine Clinic of Karolinska University Hospital, Stockholm, Sweden, between January 2009 and January 2020. Sperm quality was assessed by total sperm count, concentration, and motility. Sperm quality by disease groups was compared with the reference population data of fertile men defined by the World Health Organization (WHO). Results: Among the 1252 patients who provided samples for cryopreservation, 1063 had cancer and 189 had nonmalignant diseases. The most common malignant indications included testicular cancers (n = 501) and Hodgkin lymphoma (n = 102). Among those with nonmalignant disease, 35% (n = 66) had testicular disease. Sperm quality was significantly lower in all groups of patients with cancer compared with the reference population. In total, azoospermia was found in 8% of the patients with cancer, in 9% of those with nonmalignant testicular disease, and in 3% of the remaining men with nonmalignant disease. Conclusion: Sperm quality in adult patients with cancer was significantly impaired compared with the WHO reference population standards for fertile men. For adolescent patients, standard reference values are lacking. AYAs wishing to preserve fertility should receive individualized counseling regarding sperm quality at the time of cryopreservation, and in selected cases, banking of additional samples should be recommended depending on the sperm quality parameters.

Advancements in Understanding and Enhancing Antioxidant-Mediated Sperm Cryopreservation in Small Ruminants: Challenges and Perspectives.

Cryopreservation poses significant challenges to the preservation of sperm integrity and function, particularly in small ruminants where cryodamage is pronounced. This review explores the molecular mechanisms underlying sperm cryodamage and strategies for improving cryopreservation outcomes, with a focus on the role of antioxidants. Cryopreservation-induced alterations in proteins and RNA transcripts critical for sperm function, including motility, capacitation, fertilization, and embryo development, are discussed. Proteomic, transcriptomic, and epigenomic advancements have provided valuable insights into these mechanisms, offering potential biomarkers for predicting sperm freezability and enhancing cryopreservation strategies. Combining technologies such as mass spectrometry and flow cytometry allows for a comprehensive understanding of molecular and cellular changes induced by the freezing-thawing process. However, challenges remain in optimizing cryoprotectant formulations and antioxidant supplementation to improve post-thaw sperm fertility. Further research is needed to explore a wider range of novel cryoprotectants, antioxidants, and proteins for cryopreservation media, as well as to validate their efficacy in enhancing sperm viability and function. Additionally, investigations into the effects of cryopreservation on RNA transcripts and epigenetic factors in small ruminant species are warranted to advance our understanding of sperm preservation. Overall, this review highlights the importance of antioxidants in mitigating cryodamage and underscores the need for continued research to refine cryopreservation protocols and improve reproductive outcomes in small ruminants.

Testicular Cancer Survivorship and Fertility Preservation.

Testicular cancer disproportionally affects men of reproductive age making fertility an important aspect of testicular cancer survivorship. Men with testicular cancer have more semen parameter abnormalities and a higher incidence of infertility compared to the general population. All treatment options for testicular cancer negatively affect fertility with recovery rates varying by treatment. For these reasons, clinicians should offer sperm cryopreservation, ideally before orchiectomy to maximize the possibility of biologic paternity, if desired. Several innovations have positively impacted this space including direct-to-consumer cryopreservation and bench research demonstrating the feasibility of reintroducing testicular cells post-therapy.

Cryopreserved testicular spermatozoa among patients with azoospermia.

PURPOSE: To investigate cryopreserved testicular spermatozoa among patients with azoospermia. METHODS: In this retrospective study spanning from October 1993 to December 2021, we examined men diagnosed with azoospermia who underwent testicular spermatozoa cryopreservation. Data from medical records included utilization and disposal of sperm samples, age at initial cryopreservation. We analyzed the data over 20 years using Kaplan-Meier curves, compared age with the log-rank test, and assessed hazard ratios (HR) with 95% confidence intervals (CI) using Cox regression analysis. RESULTS: A total of 356 patients with a mean age of 32.1 ± 6 were included. Of these, 225 patients utilized thawed testicular sperm for fertility treatments, with 118 patients using all their frozen straws and 107 patients partially using their stored straws. Additionally, 29 patients opted for disposal (six patients partially used their testicular spermatozoa before disposal), resulting in 108 patients who neither used nor disposed of their straws. From a laboratory standpoint, nearly 90% of patients contributed a single testicular sample, which was subsequently divided and cryopreserved as straws, with a median of 4 straws per sample. Notably, in the older age group (> 35 years old), there were a significantly lower usage rate and a higher disposal rate compared to the younger age groups (p < 0.05 for both), corroborated by univariable Cox analysis. CONCLUSIONS: This extensive study unveils unique patterns in the preservation and disposal of testicular spermatozoa among azoospermic patients. Most patients utilize a significant portion of their stored samples, while older patients tend to use their testicular spermatozoa less frequently.

Semen cryopreservation for an oncological reason: a retrospective study.

RESEARCH QUESTION: How do cancer type and treatment affect semen quality before and after treatment, and what effect does it have in their clinical management of infertility? Also, what is the rate of patients using cryopreserved semen samples after treatment? DESIGN: Patients who cryopreserved spermatozoa for oncological reasons between 2000 and 2022 in IVI clinics in Spain were retrospectively reviewed. Semen parameters were analysed before and after treatment, and utilization and destruction rates were calculated. Total motile sperm count (TMSC) was used for assisted reproductive technology (ART) counselling. RESULTS: A total of 724 patients cryopreserved their semen during the study period. The semen parameters of the cancer patients' semen before and after treatment were heterogeneous, with significant differences between cancer type and semen parameters. The utilization rate was relatively low (0.4%), whereas the destruction rate was 23.1%. CONCLUSION: Cancer and antineoplastic treatment affect everyone differently. Therefore, sperm cryopreservation should be offered to all patients before starting treatment to ensure their reproductive future. Furthermore, in addition to considering the semen parameters defined by the World Health Organization, it is important to use TMSC in the diagnosis of men to choose appropriate ART according to type of cancer.

Effects of meteorology and lunar cycle on the post-thawing quality of avian sperm.

Introduction: Various climatological and lunar cycle parameters have a direct impact on animal reproduction, and in the case of the avian species, spermatozoa are extremely sensitive to heat stress. These parameters could influence sperm freezability, which will ultimately affect post-thawing semen quality, being sperm motility in roosters a relevant indicator of this quality as it is highly related to fertility. Therefore, the objective of the present study is to determine which are the climatological and lunar cycle parameters that have a greater effect on sperm freezability in roosters. Methods: Sperm was obtained from 16 Utrerana breed roosters and a total of 27 replicates were performed. A pool was made with those ejaculates that met the minimum quality criteria for each replicate, and four freezing-thawing samples per replicate were analyzed. The straws were thawed, and sperm motility was evaluated, classifying the results obtained into four seminal quality groups according to the guidelines of the Food and Agriculture Organization of the United Nations (Group 1: Good, Group 2: Satisfactory, Group 3: Acceptable but undesirable and Group 4: Unsatisfactory). The following traits were recorded for each day of semen collection: maximum temperature, minimum temperature, maximum barometric pressure, minimum barometric pressure, maximum gust, wind direction, mean wind speed, sunshine hours, rainfall, moon phase, and percentage of illuminated lunar surface over the total area. Results: A discriminant canonical analysis was performed to determine which of these parameters offered the most information when classifying an ejaculate in each quality group, with minimum temperature, the new moon as moon phase, minimum barometric pressure, and rainfall being the most significant variables. Discussion: According to the results obtained, semen quality decreases when temperature and precipitation are lower, pressure is higher, and when there is a new moon phase. Therefore, these environmental conditions should be avoided for sperm collection and processing.

Applying a heat transfer mathematical model for the cryopreservation of rainbow trout (Oncorhynchus mykiss) sperm: How straw location over liquid nitrogen level affects freezing rate and fertilization yield.

Cryopreservation of rainbow trout semen under field conditions was analyzed. Straw location over liquid nitrogen level is a crucial variable that affects freezing rate and fertilization yield due to changes in nitrogen vapor external temperature. The objectives were: to analyze cryopreservation protocols by experimentally measuring the cooling rates and fertilization yield of 0.5 ml plastic straws located in nitrogen vapor at different heights corresponding to different external temperatures; to numerically simulate the freezing process, by solving the heat transfer partial differential equations with the corresponding thermo-physical properties of the biological system and the plastic straw; to evaluate and analyze the surface heat transfer coefficient (h) during the freezing process of the straws; to introduce a new variable, the characteristic freezing time (tc), that enables comparison between protocols; this variable was defined as the elapsed period between the initial freezing temperature and a final reference temperature of -40 °C (temperature in which more than 80 % of the water is in a frozen state). The mathematical model predicted the temperature distribution inside the straw, showing a low effect of straw plastic materials (polyethylene-terephthalate glycol, polyvinyl-chloride, and polypropylene) on freezing rates. The average h value obtained from numerical simulations was 25.5 W/m2 K, close to that obtained from the analytical Nusselt correlation for natural convection. An improvement on fertilization trials was observed when the average external nitrogen temperature was -129.6 °C (temperature range: -94 to -171 °C) with an average tc of 56.8 s (ranging between 47 and 72 s). These results corresponded to a height above the level of liquid nitrogen of 2 cm. Comparison with literature reported data showed satisfactory results. Applying mathematical models in the cryobiology field achieved results that are relevant for cryopreservation activities.

Assessment of reproductive outcomes of fresh versus cryopreserved ejaculated sperm samples-a retrospective analysis of 44 423 oocyte donation ICSI cycles.

STUDY QUESTION: Does the use of frozen sperm affect live birth rate (LBR) and cumulative LBR (CLBR) compared to fresh sperm samples in oocyte donation ICSI cycles? SUMMARY ANSWER: Although there were slight decreases in pregnancy rates (PRs) and LBR, as well as CLBR per embryo replaced and per embryo transfer (ET), when frozen sperm samples were used compared to fresh ejaculates, their clinical impact was limited. WHAT IS KNOWN ALREADY: Sperm cryopreservation is part of the daily routine in reproduction clinics worldwide because of its many advantages in cycle planning. Nonetheless, there is a lack of agreement in terms of its impact on the outcomes of ICSI cycles. Previous studies showed conflicting conclusions and focused on different populations, which makes reaching consensus on the impact of sperm freezing-thawing complicated. Moreover, classical parameters are used to assess cycle success: pregnancy, live birth and miscarriage rates per ET. This study reports those measurements plus CLBR, which more accurately reflects the impact of the technique on the likelihood of achieving a newborn. STUDY DESIGN, SIZE, DURATION: A retrospective multicenter observational cohort study, including data from 37 041 couples and 44 423 ICSI procedures from January 2008 to June 2022, was carried out. The group using frozen sperm included 23 852 transferred embryos and 108 661 inseminated oocytes, whereas the fresh sample group comprised 73 953 embryos replaced and 381 509 injected oocytes. PARTICIPANTS/MATERIALS, SETTING, METHODS: Outcomes measured per first ET and per ET were compared between groups using Fisher's exact test and Chi-squared test, as appropriate. Binary-logistics regression models were used to adjust the analyses according to clinically relevant co-variables. Kaplan-Meier curves plotted the CLBR per oocyte inseminated, per embryo replaced and per ET, and compared between groups using the Mantel-Cox test. Cox regressions were employed for the multivariate analyses of CLBR. MAIN RESULTS AND THE ROLE OF CHANCE: The frozen sperm group showed a slightly lower biochemical (3.55% and 2.56%), clinical (3.68% and 3.54%) and ongoing (3.63% and 3.15%) PR compared to the cycles using fresh sperm, respectively, both per first ET and per ET. LBR was 4.57% lower per first ET and 3.95% lower per ET in the frozen sperm group than the fresh sperm group. There was also a subtle increase of 2.66% in biochemical miscarriage rate per ET when using frozen versus fresh sperm. All these differences remained statistically significant after the multivariate analysis (adjusted P ≤ 0.001). There were statistically significant differences in CLBR per embryo replaced and per ET but not per oocyte used (adjusted P = 0.071). Despite the statistical significance of the differences between the groups, those using frozen sperm required only 0.54 more oocytes injected, 0.45 more embryos transferred and 0.41 more ET procedures, on average, to achieve a live birth compared to the fresh samples. LIMITATIONS, REASONS FOR CAUTION: The retrospective nature of the study subjects the data to biases or potential errors during annotation on the source clinical and cycle records. This study uses multivariate analyses to control biases as much as possible. Using the oocyte donation model also contributes to reducing heterogeneity in the oocyte quality factor. WIDER IMPLICATIONS OF THE FINDINGS: The large sample sizes included in this study allowed for the detection of small changes in cycle success rates between groups. Although statistically significant, the decrease in PRs, LBR, and CLBR when using frozen sperm can be clinically overlooked in favor of the many benefits of sperm cryopreservation. STUDY FUNDING/COMPETING INTEREST(S): None declared. TRIAL REGISTRATION NUMBER: Not applicable.