Effect of sperm storage and selection techniques on sperm parameters

The role of alginate oligosaccharide on boar semen quality: A research review

Alginate is the general term of a polysaccharide which is widely used in the area of pharmaceutics and the food industry and is known for its unique biological activities. However, due to the low water solubility and large viscosity of alginate, its development and utilization in the agricultural field are limited. Alginate oligosaccharide (AOS) is a degradable product derived from alginate and has attracted much attention in recent years because of its specific characteristics such as a low molecular weight, high water solubility, and non-toxicity. Boar semen quality, which is affected by various factors, is an important indicator for measuring reproductive performance of boars. With the development of artificial insemination technology, high quality semen has been more and more important. Therefore, increasing semen quality is an important means to improve the reproductive performance in swine industry. In this research review, we used the PubMed database and Google Scholar and web of science to search for relevant literature on the topic of AOS in relation to boar semen quality. Key words used were alginate oligosaccharide, boars, semen quality, microbiota and metabolites. The purpose of this review article was to describe the current knowledge on the relationship between AOS and boar semen quality, and provide an overview of solutions for the decline in the boar semen quality in specific conditions. Based on the existing literature, it is evident that AOS can be used as a new type of food additive. This review paper provides a theoretical basis for the production of high-quality boar sperm and, suggests that, in the future, AOS can even aid in treating human infertility.

The Use of Non-Apoptotic Sperm Selected by Magnetic Activated Cell Sorting (MACS) to Enhance Reproductive Outcomes: What the Evidence Says

Sperm selection of the most competent sperm is a promising way to enhance reproductive outcomes. Apoptosis is the programmed cell death process to maintain tissue homeostasis, and MACS sperm selection of non-apoptotic cells enables the removal of apoptotic sperm from an ejaculate, thus leaving the non-apoptotic available to be microinjected, but given the associated costs of adding these sperm selection steps to the routine practice, there is a need for a careful examination of the literature available to answer questions such as who can benefit from this MACS, how significant this improvement is, and how robust the evidence and data available supporting this choice are. Thus, the aim of this narrative review was to objectively evaluate the available evidence regarding the potential benefits of the use of MACS. From the literature, there are controversial results since its implementation as an in vitro fertilization add-on, and this may be explained in part by the low quality of the evidence available, wrong designs, or even inadequate statistical analyses. We concluded that the benefits of adding MACS are unclear, and further methodologically sound research on specific populations is much needed before offering it clinically.

Semen Cryopreservation for Men Banking for Oligozoospermia, Cancers, and Other Conditions: 24 Years' Experience of an Italian Bank

BACKGROUND

Sperm cryopreservation is recommended to preserve male fertility for cancer patients or other medical conditions at risk of sperm decline. Whether motility and viability recovery rates vary depending on the medical conditions requiring cryopreservation is poorly known. We report here on the 24-year experience of our semen bank.

METHODS

Motility and viability recovery rates were evaluated in 1973 collections from patients with various medical conditions and 67 collections from donors, and the results were related to basal semen quality.

RESULTS

Motility and viability recovery were highly related to basal semen quality and varied between cancer and non-cancer conditions, independently of the duration of cryopreservation and patient age. In samples with a sperm number below 2 × 10⁶/mL, recovery rates approximated to zero. The highest recovery rates were found in donor collections. Cut-off values for the recovery of at least 1% motile spermatozoa were established based on initial semen quality.

CONCLUSIONS

Our results indicate that the occurrence of any pathological or medical condition resulted in lower recovery rates with respect to donors, indicating that intrinsic sperm characteristics drive susceptibility to cryodamage. Established cut-off values for motility recovery can be useful for patient counseling as well as for ART laboratories to decide the type of procedure.

Sperm Cryopreservation Today: Approaches, Efficiency, and Pitfalls

The cryopreservation of human spermatozoa has been an option for patients undergoing chemo or radiotherapies since the late 1950s. Presently, there are different techniques for the cryopreservation of spermatozoa. The most commonly used techniques are programmable slow freezing and freezing on liquid nitrogen vapors, while the use of vitrification is still not accepted as clinically relevant. Although there have been many improvements, the ideal technique for achieving better post-thaw sperm quality continues to be a mystery. A major obstacle during cryopreservation is the formation of intracellular ice crystals. Cryodamage generated by cryopreservation causes structural and molecular alterations in spermatozoa. Injuries can happen because of oxidative stress, temperature stress, and osmotic stress, which then result in changes in the plasma membrane fluidity, motility, viability, and DNA integrity of the spermatozoa. To prevent cryodamage as much as possible, cryoprotectants are added, and in some clinical trial cases, even antioxidants that may improve post-thaw sperm quality are added. This review discusses cryopreservation techniques, cryodamage on molecular and structural levels, and cryoprotectants. It provides a comparison of cryopreservation techniques and describes recent advances in those techniques.

A new cryotop vial device system provides an aseptic cryoprotectant-free and centrifuge-free cryopreservation of human spermatozoa (a closed system)

Single sperm cryopreservation is a new method to preserve small numbers of spermatozoa in small droplets. So far, several devices have been introduced for this technique, but more studies are needed for its optimization. The aim of this study was optimizing the previous device for low number of spermatozoa and low volume semen, which led to design of Cryotop Vial device. Normal semen samples from 25 patients were prepared by swim-up method and divided into four groups: Fresh (F), Rapid freezing (R) and ultra-rapid freezing with Cryotop Device (CD) and Cryotop Vial Device (CVD). In R group, the diluted sperm suspension with sperm freezing medium was cooled in the vapor phase and then immersed in liquid nitrogen. Ultra rapid freezing was performed with sucrose in small volume using the Cryotop Device (CD) or Cryotop Vial Device (CVD). Sperm viability, motility, fine morphology, mitochondrial activity and DNA fragmentation were assessed in all samples. All sperm parameters decreased significantly in all the cryo groups compared to the fresh group. The comparison between the cryo groups showed that progressive motility (69.28 ± 6.82 vs. 55.68 ± 9.04, and 54.76 ± 5.34, p < 0.001) and viability (77.36 ± 5.48 vs.68.84 ± 8.51, p < 0.001, and 70.04 ± 7.44, P = 0.002) were significantly higher in the CVD compared to the CD and R groups respectively. DNA fragmentation was also significantly lower in both ultra-rapid freezing groups (CD and CVD) compared to the R group. Fine morphology and mitochondrial activity were not different between the cryo groups. The CVD as a cryoprotectant and centrifuge-free technique preserved sperm motility, viability and DNA integrity after cryopreservation better than other groups.

Optimization of Sperm Cryopreservation Formulation in Portunus trituberculatus

Portunus trituberculatus is a very important marine economic species, and its aquaculture industry has been developing rapidly. However, the phenomenon of marine wild capture of P. trituberculatus and germplasm degradation has become increasingly serious. It is necessary to develop the artificial farming industry and carry out germplasm resource protection, for which sperm cryopreservation technology is an effective method. This research compared three methods (mesh-rubbing, trypsin digestion, and mechanical grinding) for acquiring free sperm, and the best method was mesh-rubbing. Then, the optimal cryopreservation conditions were selected, and the optimal formulation was sterile calcium-free artificial seawater, the optimal cryoprotectant was 20% glycerol, and the best equilibrium time was 15 min at 4 °C. The optimal cooling program was suspending the straws at 3.5 cm on the liquid nitrogen surface for 5 min and then storing them in liquid nitrogen. Finally, the sperm were thawed at 42 °C. However, the expression of sperm-related genes and the total enzymatic activities of frozen sperm were significantly decreased (p < 0.05), which showed that sperm cryopreservation damaged the sperm. Our study improves the sperm cryopreservation technology and the yield of aquaculture in P. trituberculatus. Additionally, the study provides a certain technical basis for the establishment of a sperm cryopreservation library of crustaceans.

Analyzing the Differential Impact of Semen Preparation Methods on the Outcomes of Assisted Reproductive Techniques

Sperm separation plays a critical role in assisted reproductive technology. Based on migration, density gradient centrifugation and filtration, a properly selected sperm could help in increasing assisted reproductive outcomes in teratozoospermia (TZs). The current study aimed to assess the prognostic value of four sperm selection techniques: density gradient centrifugation (DGC), swim-up (SU), DGC-SU and DGC followed by magnetic-activated cell sorting (DGC-MACS). These were evaluated using spermatozoa functional parameters. A total of 385 infertile couples underwent the procedure of intracytoplasmic sperm injection (ICSI), with an isolated teratozoospermia in the male partner. Semen samples were prepared by using one of the mentioned sperm preparation techniques. The improvements in the percentage of normal mature spermatozoa, rate of fertilization, cleavage, pregnancy and the number of live births were assessed. The normal morphology, spermatozoa DNA fragmentation (SDF) and chromatin maturity checked by using chromomycin A3 (CMA3) with DGC-MACS preparation were better compared to the other three methods. Embryo cleavage, clinical pregnancy and implantation were better improved in the DGC-MACS than in the other tested techniques. The DGC-MACS technique helped in the selection of an increased percentage of normal viable and mature sperm with intact chromatin integrity in patients with teratozoospermia.

Motherhood, Fairness, and Flourishing: Widening Reproductive Choices in Saudi Arabia

In a landmark Fatwa, Saudi Arabia's highest religious authority-The Council of Senior Scholars-declared the Islamic permissibility of oocyte cryopreservation. The fatwa sanctioned the retrieval, preservation, and future use of oocytes, ovarian tissue, and whole ovaries from cancer patients receiving gonadotoxic interventions. Although momentous, the fatwa's specification of cancer patients effectively rendered this technology unavailable to others to whom it may be similarly beneficial, including patients with other medical conditions or patients seeking elective cryopreservation. This article argues in favor of widening reproductive choices through expanded access to oocyte cryopreservation in Saudi Arabia-regardless of the underlying cause of infertility-on three grounds: the technology's compliance with Islamic law, as a matter of fairness in medical practice, and as a means to support the well-being and flourishing of Saudi women within the context of a national societal and economic transformation strategy closely linked to their success.

Advantages of vitrification preservation in assisted reproduction and potential influences on imprinted genes

Cryopreservation has important application in assisted reproductive technology (ART). The vitrification technique has been widely used in the cryopreservation of oocytes and embryos, as a large number of clinical results and experimental studies have shown that vitrification can achieve a higher cell survival rate and preimplantation development rate and better pregnancy outcomes. Ovarian tissue vitrification is an alternative method to slow freezing that causes comparatively less damage to the original follicular DNA. At present, sperm preservation mainly adopts slow freezing or rapid freezing (LN2 vapor method), although the vitrification method can achieve higher sperm motility after warming. However, due to the use of high-concentration cryoprotectants and ultra-rapid cooling, vitrification may cause strong stress to gametes, embryos and tissue cells, resulting in potentially adverse effects. Imprinted genes are regulated by epigenetic modifications, including DNA methylation, and show single allele expression. Their accurate regulation and correct expression are very important for the placenta, fetal development and offspring health. Considering that genome imprinting is very sensitive to changes in the external environment, we comprehensively summarized the effect of cryopreservation—especially the vitrification method in ART—on imprinted genes. Animal studies have found that the vitrification of oocytes and embryos can have a significant impact on some imprinted genes and DNA methylation, but the few studies in humans have reported almost no influence, which need to be further explored. This review provides useful information for the safety assessment and further optimization of the current cryopreservation techniques in ART.

Improvement of human sperm properties with platelet-rich plasma as a cryoprotectant supplement

PURPOSE

Platelet-rich plasma (PRP) is a remarkable substance, which involves the growth and proliferation of all cell types. As a source of growth factors, we evaluated whether sperm cryopreservation supplemented with PRP improves the rates of sperm motility, viability, and DNA integrity after vitrification compared with conventional cryo-medium.

MATERIALS AND METHODS

20 normal semen specimens were collected from healthy men. After swim-up preparation, each sample was divided into four aliquots. One, as control, received no treatment, and the other three experimental samples were treated with three different concentrations of PRP as cryoprotectant. Sperm parameters were examined before and after freezing procedure.

RESULTS

PRP had no significant effect on sperm count. Meanwhile, the percentage of sperm progressive motility and viability in the PRP treated samples with 1×10⁵ /µL concentration was significantly higher than control group. Besides, the rate of immotile sperms in these samples was significantly lower than the control. Sperm viability was significantly higher in the PRP samples at 1×10⁵/µL concentration. In the case of DNA integrity, CMA3 staining showed that the lower PRP concentration was correlated with the higher rate of abnormal spermatozoa. SCD showed that the rate of abnormal sperms in the PRP samples with 1×10⁵ /µL concentration was significantly lower than control group.

CONCLUSIONS

This study showed a protective effect of PRP on human sperm quality at an optimized concentration after vitrification. Besides, the effects of PRP supplementation of sperms on successful fertility following sperm preservation will be of interest.

The effect of Caulerpa sertularioides extract on bull sperm freezablity and subsequent embryo development

Artificial insemination is a valuable and essential tool in genetic improvement programs, and its success requires proper semen collection, freezing, and thawing procedures. Nowadays, despite applying of advanced protocols for semen cryopreservation, post-thawing sperm quantitative and qualitative parameters are not satisfactorily comparable to fresh sperm. The present study was designed to evaluate the effects of the supplementation of an alcoholic extract of Caulerpa sertolarioides alga into the tris-egg yolk-based Simmental bull sperm freezing media. The pooled semen samples were divided into five groups, of which four were supplemented with 500, 1000, 1500, and 2000 ppm alga extract and one allocated as a control. Total motility, progressive motility, plasma membrane integrity, DNA integrity, apoptosis, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and total antioxidant capacity (TAC) of sperm were measured. The frozen sperm from each group were used for IVF on the slaughterhouse-derived oocytes. Fertilization, cleavage, and blastocyst rates were assessed for all groups. Total motility, progressive motility, and velocity curvilinear (VCL) parameters were higher (p ≤ 0.05) in group 1000 ppm than the control group. Velocity in a straight path (VSL) was higher (p ≤ 0.05) in all treatment groups except in 500 ppm compared to the control group. Average path velocity (VAP) was higher (p ≤ 0.05) in 1000 and 1500 ppm groups than in the control group. Straightness (STR) showed a higher value (p ≤ 0.05) in 1000 and 2000 ppm than the control group. Groups 500 and 1000 ppm showed more viable sperm than the control group (p ≤ 0.05). DNA damage was lower (p ≤ 0.05) in group 1000 ppm than in the control group. HOST was higher (p ≤ 0.05) in all groups than in the control group. SOD, GPx, and TAC were higher (p ≤ 0.05) in 1000 ppm than the control and all other groups. Apoptosis was not significantly different among the treatment and control groups. In conclusion, supplementation of alcoholic extract of Caulerpa sertularioides into the Simmental bull freezing extender ameliorated the sperm parameters after the freeze-thawing process. Moreover, the results of this study indicated that the best dose to achieve the antioxidant properties of the alga extract in Simmental bull sperm freezing media was 1000 ppm. It was also evident that 1000 ppm alga extract supplementation into the bull sperm improved fertilization, cleavage, and blastocyst rates.

Vapour fast freezing with low semen volumes can highly improve motility and viability or DNA quality of cryopreserved human spermatozoa

Objectives

To challenge a vapour fast freezing (VFF) cryopreservation procedure (conventional VFF) with several vitrification protocols and VFF conducted with small semen volumes (10 μl, microVFF), in order to implement a procedure for sperm banking in subjects with small sperm number.

Materials and methods

Conventional VFF was conducted with test yolk buffer (TYB) as freezing medium and 500 μl straws as carriers. MicroVFF was conducted with TYB and using tips or cell sleepers as carriers. Vitrification was performed with TYB or SpermFreeze as freezing medium and with microspheres and tips as carriers. The effect of different procedures on progressive and total motility, viability, oxidative stress and DNA fragmentation of spermatozoa (sDF) was determined. Fresh and thawed samples, the latter after adequate washing/centrifuging, were evaluated. In some experiments, motility and viability recovery was determined in thawed samples, omitting the washing/centrifuging step.

Results

All the cryopreservation procedures blunted sperm motility and viability and induced increase of oxidative stress and sDF. However, VFF better preserved sperm motility and viability and less induced oxidative stress and sDF than vitrification, independently from the freezing medium and the carriers used in the latter. MicroVFF with cell sleepers resulted in a percentage increase of 57.58 ± 63.63%, 48.82 ± 74.96% and 24.55 ± 39.20% of, respectively, progressive and total motility and viability compared to the conventional VFF. Further, when tips were used, microVFF resulted in a percentage decrease of 15.77 ± 20.77% of sDF with respect to conventional VFF. Finally, omission of washing/centrifuging in post thawed samples, resulted in a much lower negative effect on motility and viability.

Discussion and conclusion

VFF, and in particular microVFF, better prevents sperm cryodamage than vitrification. Washing/centrifuging step after sample thawing seems to be responsible for a relevant fraction of damage to sperm motility and viability. Overall, our results are promising for developing a novel strategy of sperm banking in subjects with small sperm number, where low semen volumes are mandatory.

The use of fresh compared to frozen ejaculated sperm has no impact on fresh embryo transfer cycle reproductive outcomes

PURPOSE

To compare the reproductive outcomes of fresh embryo transfer (ET) cycles utilizing fresh versus frozen ejaculated sperm.

METHODS

First autologous fresh embryo transfer cycles at a single high-volume academic institution between 2013 and 2019 were retrospectively reviewed. IVF cycles using ejaculated sperm were included, and cycles using donor or surgically retrieved sperm were excluded. Sperm concentration was stratified as ≥ 5 and < 5 million/ml. The primary outcome was live birth, and the secondary outcomes were clinical intrauterine pregnancy (IUP) and miscarriage. A multivariable logistic regression model for the aforementioned outcomes was adjusted a priori for sperm concentration as well as maternal and paternal age.

RESULTS

A total of 6128 couples were included. Of these, 5780 (94.3%) utilized fresh sperm, and 348 (5.7%) frozen sperm. A total of 5716 (93.2%) had sperm concentrations ≥ 5 million/ml and 412 (6.7%) had sperm concentrations < 5 million/ml. On multivariable logistic regression, the use of freshly ejaculated sperm was not associated with significantly different odds of clinical IUP, miscarriage, or live birth when compared to cycles using frozen sperm.

CONCLUSION

For couples conceiving via fresh ET, the use of fresh versus frozen ejaculated sperm is not associated with reproductive outcomes.

Beneficial effects of hypotaurine supplementation in preparation and freezing media on human sperm cryo-capacitation and DNA quality

BACKGROUND

Although widely used, slow freezing considerably modifies the functions of human spermatozoa. Cryopreservation induces nuclear sperm alterations and cryo-capacitation, reducing the chances of pregnancy. Hypotaurine is naturally present in the male and female genital tracts and has capacitating, osmolytic and anti-oxidant properties. The analysis were performed on surplus semen of men with normal (n = 19) or abnormal (n = 14) sperm parameters. Spermatozoa were selected by density gradient centrifugation before slow freezing. For each sample, these steps were performed in parallel with ("H+" arm) or without ("H-" arm) hypotaurine supplementation. After thawing, we measured total and progressive mobility, vitality, acrosome integrity, markers of capacitation signaling pathway and nuclear quality. For the latter, we focused on sperm chromatin packaging, DNA fragmentation and the presence of vacuoles in the sperm nucleus.

RESULTS

Post-thaw spermatozoa selected and frozen in the presence of hypotaurine had a higher vitality (+ 16.7%, p < 0.001), progressive and total motility (+ 39.9% and +  21.6% respectively, p < 0.005) than spermatozoa from the control "H-" arm. Hypotaurine also reduced the non-specific phosphorylation of the capacitation protein markers P110 and P80 (p < 0.01), indicating a decrease in cryo-capacitation. Hypotaurine supplementation reduced chromatin decondensation, measured by chromomycin A3 (- 16.1%, p < 0.05), DNA fragmentation (- 18.7%, p < 0.05) and nuclear vacuolization (- 20.8%, p < 0.05).

CONCLUSION

Our study is the first to demonstrate beneficial effects of hypotaurine supplementation in preparation and freezing procedures on human spermatozoa sperm fertilization capacity and nucleus quality. Hypotaurine supplementation limited cryo-capacitation, increased the proportion of live and progressively motile spermatozoa and reduces the percentage of spermatozoa showing chromatin decondensation, DNA fragmentation and nuclear vacuolation.

TRIAL REGISTRATION

Clinical Trial, NCT04011813 . Registered 19 May 2019 - Retrospectively registered.

Does Microfluidic Sperm Sorting Affect Embryo Euploidy Rates in Couples with High Sperm DNA Fragmentation?

Male infertility contributes as the main factor in 30-50% of infertility cases. Conventional methods for sperm preparation have induced questioning of sperm recovery rates. The microfluidic sperm sorting (MSS) technique selects highly motile sperm with lower levels of SDF (sperm DNA fragmentation) compared to conventional sperm sorting techniques. This study aimed to determine whether utilizing this technique will reveal better embryo quality and euploidy rates in couples with repeated implantation failure (RIF) and high SDF in a new PGT-A (preimplantation genetic testing for aneuploidies) cycle. This retrospective study included couples referred to PGT-A for previous repeated ART (assisted reproductive techniques) cycle failures and with high SDF. In their new cycles, couples who accepted the technique were assigned to the MSS group, and the rest were managed with DGC (density-gradient centrifugation). Two groups were compared in terms of fertilization and euploidy rates, clinical miscarriage and live birth rates, the total number of blastocysts, and top quality blastocysts. There was no difference between the groups regarding fertilization rates, euploidy rates, clinical miscarriage, and live birth rates. The total number of blastocysts and top quality blastocysts were significantly higher in the MSS group. The MSS technique provides a higher number of top-quality blastocysts than DGC; however, neither euploidy nor live birth rates improved. Studies focusing on confounding factors to embryonic genomic status in the presence of high SDF are needed.

Sperm Selection Procedures for Optimizing the Outcome of ICSI in Patients with NOA

Retrieving spermatozoa from the testicles has been a great hope for patients with non-obstructive azoospermia (NOA), but relevant methods have not yet been developed to the level necessary to provide resolutions for all cases of NOA. Although performing testicular sperm extraction under microscopic magnification has increased sperm retrieval rates, in vitro selection and processing of quality sperm plays an essential role in the success of in vitro fertilization. Moreover, sperm cryopreservation is widely used in assisted reproductive technologies, whether for therapeutic purposes or for future fertility preservation. In recent years, there have been new developments using advanced technologies to freeze and preserve even very small numbers of sperm for which conventional techniques are inadequate. The present review provides an up-to-date summary of current strategies for maximizing sperm recovery from surgically obtained testicular samples and, as an extension, optimization of in vitro sperm processing techniques in the management of NOA.

Sperm Selection by Magnetic-Activated Cell Sorting before Microinjection of Autologous Oocytes Increases Cumulative Live Birth Rates with Limited Clinical Impact: A Retrospective Study in Unselected Males

Simple Summary

Many couples attending infertility clinics still need to repeat treatments and undergo several failed attempts before achieving a healthy newborn, which leaves room for improvement in the techniques we currently use in the clinic. Among the different procedures susceptible to improvement, the selection of the most adequate sperm to be injected inside the egg is crucial to the cycle’s success. Magnetic-activated cell sorting (MACS) is a technique that removes physiologically abnormal sperm that have started a programmed cell death (apoptotic) process from a semen sample. However, it is not recommended to all patients because there is no agreement between the published literature on whether it improves reproductive outcomes. This study used data from all intracytoplasmic sperm injection cycles performed using the patient’s own oocytes in our clinics from January 2008 to February 2020. Our findings support that MACS should not be recommended to all infertile couples, since there was no significant difference in results compared to treatments in which MACS was not used. This study provides clinicians and patients with more accurate information on how MACS will impact their chances of pregnancy, and it will lead to studies focused on specific populations to which the technique can be particularly helpful.

Abstract

The application of MACS non-apoptotic sperm selection in infertility clinics is controversial since the published literature does not agree on its effect on reproductive outcomes. Therefore, it is not part of the routine clinical practice. Classical measures of reproductive success (pregnancy or live birth rates per ovarian stimulation) introduce a bias in the evaluation of a technique’s effect, since only the best embryo is transferred. This retrospective, multicenter, observational study evaluated the impact of MACS on reproductive outcomes, measuring results in classical parameters and cumulative live birth rates (CLBR). Data from ICSI cycles using autologous oocyte in Spanish IVIRMA fertility clinics from January 2008 to February 2020 were divided into two groups according to their semen processing: standard practice (reference: 46,807 patients) versus an added MACS sperm selection (1779 patients). Only when measured as CLBR per embryo transferred and per MII oocyte used was the difference between groups statistically significant. There were no significant differences between MACS and reference groups on pregnancy and live birth rates. In conclusion, results suggest that non-apoptotic sperm selection by MACS on unselected males prior to ICSI with autologous oocytes has limited clinical impact, showing a subtle increase in CLBR per embryo transferred.

Influence of circulating testosterone concentration on sperm cryoresistance: The ibex as an experimental model

BACKGROUND

Recent studies have noted that the circulating testosterone concentration may affect the ability of spermatozoa to survive cryopreservation. However, few attempts to confirm such a relationship have been made. Wild ruminant species have very marked seasonal changes in their reproductive function and strong annual changes in their plasma testosterone concentration.

OBJECTIVES

The present work examines the influence of induced changes in testosterone secretion on sperm variables following conventional slow freezing and ultra-rapid freezing, using the Iberian ibex as an experimental model.

MATERIALS AND METHODS

In a first experiment, testosterone levels were reduced in the middle of the rutting season (December) using the antiandrogen cyproterone acetate (CA). In a second experiment, testosterone levels were increased at the end of the rutting season (January) via the use of the androgen testosterone propionate (TP).

RESULTS

During December, the testosterone concentration was found to be higher in the blood and seminal plasma of untreated males than in those of CA-treated males (p < 0.001 and p < 0.05, respectively). Compared with controls, the TP-treated animals had higher blood plasma testosterone concentrations but lower seminal plasma testosterone concentrations during January (p < 0.01 and p < 0.001, respectively). The seminal vesicles of the TP-treated males were larger than those of untreated males (p < 0.05). When CA was administered, sperm viability improved compared with controls (p < 0.05), irrespective of the freezing protocol followed. For the ultra-rapid freezing procedure, the cryoresistance ratio for motility decreased when TP was administered (p < 0.05). The values for fresh sperm morphometric variables decreased during the 50 days after the end of CA treatment (p < 0.001) and increased over the same time after the end of TP treatment (p < 0.001).

DISCUSSION AND CONCLUSION

The circulating testosterone concentration appears to influence sperm cryoresistance. This may explain the seasonal changes seen in sperm freezability in some species, independent of fresh sperm quality.

Assessing online price transparency of sperm cryopreservation across the United States

Although the lack of information on the costs and pricing of healthcare services prevails throughout the medical industry, empiric observations have demonstrated that pricing information is even more obscured in the sperm cryopreservation market. Thus, the objectives of our study are to assess and compare online price transparency and the price of sperm cryopreservation across various healthcare settings in the United States. This study examined online pricing published by facilities that have an active registration to store spermatozoa with the Food and Drug Administration. Less than one-fifth of registered facilities display any pricing information online. Price transparency also varies among census regions and facility types. Nationally, the median initial bank fee and annual price of storage are $350 and $385 respectively. Although there were no differences in the initial fee by facility type and census region, the annual price of storing spermatozoa is highest in the Northeast, which could be attributed to laboratory techniques, demographic patterns or insurance coverage. Guidelines from professional societies or different legislation and regulatory requirements across different US states can increase price transparency, which can promote consumer decision-making and decrease the barrier for men seeking fertility preservation.

Quercetin and Naringenin Provide Functional and Antioxidant Protection to Stored Boar Semen

In this study, we evaluated the impact of 5-50 μM quercetin (QUE) and naringenin (NAR) on extended boar spermatozoa in the BTS (Beltsville Thawing Solution) medium for 72 h. Spermatozoa motion, membrane, acrosome, and DNA integrity were investigated immediately after sample dilution (0 h) as well as after 24 h, 48 h, and 72 h of semen storage. Furthermore, reactive oxygen species (ROS) and superoxide production, as well as the extent of oxidative damage to the sperm proteins and lipids, were assessed to determine the potential of QUE and NAR to prevent a potential loss of sperm vitality due to oxidative stress development. Our results indicate that the most notable parameter influenced by QUE was the mitochondrial activity, which remained significantly higher throughout the experiment (p < 0.001 and p < 0.0001; 10 μM), and which correlated with the most prominent maintenance of sperm motility (p < 0.01, 48 h; p < 0.05, 72 h). A significant membrane stabilization (p < 0.01, 24 h and 48 h; p < 0.0001, 72 h) and prevention of lipid peroxidation (p < 0.05, 24 h and 48 h; p < 0.01, 72 h) was primarily observed following administration of 10 and 25 μM NAR; respectively. Administration of 10 μM QUE led to a significant decrease of superoxide (p < 0.0001, 48 h and 72 h) while the most notable decline of ROS generation was recorded in the case of 10 and 25 μM NAR (p < 0.001). This study may provide new information on the specific mechanisms of action involved in the favorable effects of natural biomolecules on spermatozoa.

Cryopreservation Differentially Alters the Proteome of Epididymal and Ejaculated Pig Spermatozoa

Cryopreservation induces differential remodeling of the proteome in mammalian spermatozoa. How these proteome changes relate to the loss of sperm function during cryopreservation remains unsolved. The present study aimed to clarify this issue evaluating differential changes in the proteome of fresh and frozen-thawed pig spermatozoa retrieved from the cauda epididymis and the ejaculate of the same boars, with clear differences in cryotolerance. Spermatozoa were collected from 10 healthy, sexually mature, and fertile boars, and cryopreserved using a standard 0.5 mL-straw protocol. Total and progressive motility, viability, and mitochondria membrane potential were higher and membrane fluidity and reactive oxygen species generation lower in frozen-thawed (FT) epididymal than ejaculated spermatozoa. Quantitative proteomics of fresh and FT spermatozoa were analyzed using a LC-ESI-MS/MS-based Sequential Window Acquisition of All Theoretical Spectra approach. Cryopreservation quantitatively altered more proteins in ejaculated than cauda epididymal spermatozoa. Differential protein-protein networks highlighted a set of proteins quantitatively altered in ejaculated spermatozoa, directly involved in mitochondrial functionality which would explain why ejaculated spermatozoa deteriorate during cryopreservation.

A new system of sperm cryopreservation: evaluation of survival, motility, DNA oxidation, and mitochondrial activity

BACKGROUND

Sperm vitrification (V) is a method for cryopreservation, without the use of conventional cryoprotectants, by plunging the sperm suspension directly into liquid nitrogen (LN25).

OBJECTIVE

This study aimed to compare the new system of V with conventional freezing (CF) protocol using fresh spermatozoa as reference (C).

MATERIAL AND METHODS

Prospective cohort study. A total of 47 sperm samples from men attending the infertility clinic at Instituto Valenciano de Infertilidad Valencia. The sperm V solution was 0.3 M trehalose-sucrose and plunged directly in liquid nitrogen in microdroplets of 5-10 lL, using a new system collector of V. Sperm viability indicators such as sperm motility, vitality rates, mitochondrial function, and sperm DNA oxidation were assessed before and after cryopreservation. Sperm motility and vitality analysis were performed according to published guidelines of the World Health Organization (WHO, 2010). Mitochondrial function was evaluated using JC-1 (fluorescent cationic dye, 5,50,6,60-tetrachloro-1-10,3,30-tetraethyl-benzamidazolocarbocyanin iodide). Sperm DNA oxidation was determined using a fluorescent assay (Oxy-DNA test) for the detection of 8-oxoguanine. The evaluation was carried out before and after cryopreservation using flow cytometry. Statistical analysis was performed using ANOVA and chi-square test, and p < 0.05 was considered statistically significant.

RESULT(S)

Sperm parameters, including progressive motility, total motility, and viability, observed after cryopreservation were as follows: C = 74.9% [1] 12.3, CF = 27.2% [1] 8.4, V = 42.3% [1] 9.3, p < 0.001; C = 90.1 [1] 6.8, CF = 42.0 [1] 12.9, V = 61.4 [1] 11.8, p < 0.001; C = 90.0% [1] 7.4, CF = 42.5% [1] 14.6, V = 70.9% [1] 6.5, p < 0.001, respectively. Regarding Oxy-DNA and mitochondrial activity, they were significantly affected in both groups (V and CF) when compared to the control group.

DISCUSSION

The sperm V and CF have negative impact on sperm parameters as well as DNA integrity and mitochondrial activity. However, sperm V presented improved sperm motility recovery, similar levels of DNA oxidation, and, moreover, a slightly increase in mitochondrial activity when compared to the conventional method.

CONCLUSION(S)

V as an optimal protocol for sperm cryopreservation.

Cryopreservation of human spermatozoa by vitrification versus conventional rapid freezing: Effects on motility, viability, morphology and cellular defects

OBJECTIVES

Sperm cryopreservation has great potential for male infertility treatment as used in assisted reproduction technology (ART). There are a variety of cryopreservation methods in order to preserve sperm in a long term. Although conventional freezing and vitrification now are used widely, they have damage on sperm parameters as well as sperm DNA integrity. It is necessary to answer which method is better and appropriate for sperm cryopreservation. The aim of this study was to compare the effect of conventional freezing and vitrification regarding to motility, vitality and morphology of sperm found in washed and unwashed samples.

STUDY DESIGN

One hundred and five human fresh semen samples were divided into washed and unwashed halves using density-gradient centrifugation. Each group then was split into two aliquots: one cryopreserved by conventional freezing and the other by vitrification, using SpermFreeze Solution™ (Vitrolife, Västra Frölunda, Sweden) containing glycerol as a cryoprotectant. The sperm parameters were analyzed and compared between six groups: washed fresh (FW), unwashed fresh (FU), washed conventional freezing (CfW), unwashed conventional freezing (CfU), washed vitrification (VitW) and unwashed vitrification (VitU) samples.

RESULTS

Sperm progressive motility, vitality and normal morphology significantly decreased, together with an appreciable increase in sperm head, midpiece and tail defects when comparing to the fresh sperm parameters after thawing in all groups. In conventional freezing method groups, progressive motility and vitality were substantially higher than that in vitrification method groups. However, vitrification gave better results in normal morphology rates. Additionally, sperm head, midpiece and tail defects were significant lower in two vitrification groups in comparison with conventional freezing groups. Interestingly, washed groups had better sperm parameters than unwashed groups so that washing process before frozen seemed to improve sperm parameters.

CONCLUSION

Conventional freezing method resulted in better motility, viability in both washed/unwashed groups. On the contrary, spermatozoa undergoing vitrification were healthier regarding morphology with less defects than conventional freezing. Sperm washing before frozen was a beneficial preparation to sperm cryopreservation.

Vitrification and conventional freezing methods in sperm cryopreservation: A systematic review and meta-analysis

OBJECTIVE

The objective is to systematically review and synthesize the literature on the efficacy with two different cryopreservation methods used for human spermatozoa and evaluate whether vitrification protocol and quality of sperm influence effect estimates.

DESIGN

The following electronic databases were searched up to September 2017: Pubmed, Embase and Web of Science. The search strategy used the following the relevant medical subject heading (MeSH) terms, keywords, and word variants for: sperm parameters, conventional freezing, and vitrification. Queries were limited to those involving humans. Randomized controlled trials (RCTs) that published in English languages were considered eligible. Studies and references were included if they reported total motility, progressive motility, morphology, or DNA fragmentation index (DFI) for vitrified or conventional cryopreserved human spermatozoa. Patients recruited in RCTs considering sperm vitrification as one of the experimental arms and conventional freezing (including slow freezing or vapor fast freezing) sperm control as the other. Studies that had high risks of allocation concealment were excluded when performing sensitivity analysis. We specified 2 subgroup variables, including vitrification protocol and quality of spermatozoa cryopreserved, to investigate sources of heterogeneity. A meta-analysis was performed using a random effects (I² > 50%) or fixed effects (I² < 50%) model to calculate weighted mean differences (MD) and 95% CI.

RESULT(S)

The search yielded a total of 2428 articles and 13 RCTs were included for analysis. They involved 486 vitrified and 486 conventional cryopreserved sperm samples. Four sperm parameters were reported as mean differences and based on adjusted estimates in all included studies. Meta-analysis of these studies showed significantly higher total motility [weighted mean differences (WMD) 6.98; 95% confidence interval (CI) 2.94; 11.02; P < 0.0001] and progressive motility [WMD 4.59; 95% CI 0.78; 8.39; P = 0.02] of past-thawed sperm following vitrification compared with conventional freezing methods. However, DNA fragmentation index (DFI) [WMD -1.18; 95% CI -2.81; 0.45; P = 0.16] and morphology [WMD 0.11; 95% CI -0.42; 0.63; P = 0.69] of past-thawed sperm are similar between two freezing groups. Subgroup analysis shown that the vitrification protocol and quality of spermatozoa are potential risk factors for the efficacy of vitrification. Higher past-thawed sperm parameters following the cryoprotectants-free (CPAs-free) vitrification were observed, as well as a lower past-thawed sperm parameters with the cryoprotectants-presence (CPAs-presence) vitrification, which could reflect the CPAs related cytotoxicity. Meanwhile, vitrification had higher ability in preservation of high quality of spermatozoa compared with vitrification of low quality spermatozoa.

CONCLUSION(S)

According to the results of present meta-analysis, vitrification is superior to conventional freezing methods in preservation of spermatozoa, regarding total and progressive motility. However, the efficacy of vitrification is influence by using different vitrification protocol and cryopreservation of different quality spermatozoa. It is must emphasized that the results of present meta-analysis is limited by the small number of studies of variable vitrification protocol. Further well conducted studies are required to confirm the efficacy of vitrification in cryopreservation of spermatozoa, in addition, allow the examination of the two cryopreservation methods in terms of pregnancy achievement and determination of the role of clinical variable on efficacy of vitrification.

A retrospective study on sperm banking: a Uruguayan experience

Objective

The purpose of this study was to investigate the status of homologous sperm banking in Uruguay.

Methods

A retrospective investigation was performed on data collected between 2013 and 2015. Reasons for sperm banking, patient age, pre-freeze and post-thaw semen parameters, and recovery rates were analyzed.

Results

623 samples were cryobanked between 2013 and 2015. Only 324 samples were considered for analysis after selection based on inclusion criteria. In most cases the samples were stored because the patients were undergoing assisted reproductive technology (ART) treatment (n=190; 58,64%) or for oncological reasons (n=113; 34,88%). The median age of bankers was 34 years. In the cancer group, 61.95% (n=70) of the subjects had been diagnosed with testicular cancer. Medians of semen parameters for both groups were above the lower reference limits dictated by the World Health Organization (2010). In fresh samples, a significant difference was observed in progressive motility (47% vs. 56%) between ART and oncological patients. After thawing, total motility (27% vs. 32%), progressive motility (19% vs. 22%), and vitality (48% vs. 56%) differed significantly between ART and oncological bankers.

Conclusion

Semen banking has been performed successfully in Uruguay and outcomes are on par with international standards. Surprisingly, the semen parameters of the cancer group were nearly normal.

Clinical utility of sperm DNA fragmentation testing: practice recommendations based on clinical scenarios

Sperm DNA fragmentation (SDF) has been generally acknowledged as a valuable tool for male fertility evaluation. While its detrimental implications on sperm function were extensively investigated, little is known about the actual indications for performing SDF analysis. This review delivers practice based recommendations on commonly encountered scenarios in the clinic. An illustrative description of the different SDF measurement techniques is presented. SDF testing is recommended in patients with clinical varicocele and borderline to normal semen parameters as it can better select varicocelectomy candidates. High SDF is also linked with recurrent spontaneous abortion (RSA) and can influence outcomes of different assisted reproductive techniques. Several studies have shown some benefit in using testicular sperm rather than ejaculated sperm in men with high SDF, oligozoospermia or recurrent in vitro fertilization (IVF) failure. Infertile men with evidence of exposure to pollutants can benefit from sperm DNA testing as it can help reinforce the importance of lifestyle modification (e.g., cessation of cigarette smoking, antioxidant therapy), predict fertility and monitor the patient’s response to intervention.

Testicular versus ejaculated spermatozoa in ICSI cycles of normozoospermic men with high sperm DNA fragmentation and previous ART failures

As a part of male assessment, conventional sperm parameters including morphologic features have been dedicated as major factors influencing fertilisation and pregnancy rates in assisted reproductive technology (ART). Genomic integrity of spermatozoa has also been found to influence fertility prognosis, and hence, sperm DNA fragmentation index (DFI) has been adopted by many centres to document this entity. Despite several suggested approaches, there is lack of universal consensus on optimising fertility outcomes in males with high sperm DFI. In this context, the results from cycles using testicular spermatozoa (TESA) obtained by aspiration were compared with those of ejaculated spermatozoa (EJ) in normozoospermic subjects with high sperm DFI and previous ART failures. Clinical (41.9% versus 20%) and ongoing pregnancy rates (38.7% versus 15%) were significantly better and miscarriages were lower in TESA group when compared to EJ group. Sperm DFI should be a part of male partner's evaluation following unsuccessful ART attempts. When high DFI is detected (>30%), ICSI using testicular spermatozoa obtained by TESA seems an effective option particularly for those with repeated ART failures in terms of clinical, ongoing pregnancies and miscarriages even though conventional sperm parameters are within normal range.

Comparison of reproductive outcome in oligozoospermic men with high sperm DNA fragmentation undergoing intracytoplasmic sperm injection with ejaculated and testicular sperm

OBJECTIVE

To investigate the effectiveness of intracytoplasmic sperm injection (ICSI) using testicular sperm as a strategy to overcome infertility in men with high sperm DNA fragmentation (SDF).

DESIGN

Prospective, observational, cohort study.

SETTING

Private IVF centers.

PATIENT(S)

A total of 147 couples undergoing IVF-ICSI and day 3 fresh ETs whose male partner has oligozoospermia and high SDF.

INTERVENTION(S)

Sperm injections were carried out with ejaculated sperm (EJA-ICSI) or testicular sperm (TESTI-ICSI) retrieved by either testicular sperm extraction (TESE) or testicular sperm aspiration (TESA). SDF levels were reassessed on the day of oocyte retrieval in both ejaculated and testicular specimens.

MAIN OUTCOME MEASURE(S)

Percentage of testicular and ejaculated spermatozoa containing fragmented DNA (%DFI) and clinical pregnancy, miscarriage, and live-birth rates.

RESULT(S)

The %DFI in testicular sperm was 8.3%, compared with 40.7% in ejaculated sperm. For the TESTI-ICSI group versus the EJA-ICSI group, respectively, the clinical pregnancy rate was 51.9% and 40.2%, the miscarriage rate was 10.0% and 34.3%, and the live-birth rate was 46.7% and 26.4%.

CONCLUSION(S)

ICSI outcomes were significantly better in the group of men who had testicular sperm used for ICSI compared with those with ejaculated sperm. SDF was significantly lower in testicular specimens compared with ejaculated counterparts. Our results suggest that TESTI-ICSI is an effective option to overcome infertility when applied to selected men with oligozoospermia and high ejaculated SDF levels.