A novel micro-straw for cryopreservation of small number of human spermatozoon

Clinical and neonatal outcomes of using a modified micro cryotube for cryopreservation of small numbers of spermatozoa for TESA-ICSI cycles

Cryopreservation of a small number of human spermatozoa is still a major challenge for embryologists. The aim of this study was to evaluate the clinical pregnancy and neonatal outcomes of intracytoplasmic sperm injection (ICSI) using a modified micro cryotube as freezing carrier for freezing small numbers of human spermatozoa collected by testicular sperm aspiration (TESA). We conducted a retrospective study to analyses the ICSI outcomes of using frozen-thawed few testicular spermatozoa in males with obstructive azoospermia (OA) from June 2017 to June 2021. Of 155 ICSI treatment cycles, 79 cycles were allocated to frozen sperm group and a modified micro cryotube was used for freezing testicular sperm, 76 cycles were allocated as fresh sperm group. No significant differences were observed in fertilization rate, good quality embryo rate, and blastocyst rate between the frozen sperm group and fresh sperm group (P > 0.05). Similarly, in the fresh embryo transfer cycles plus the first frozen-thawed embryo transfer cycles, the total clinical pregnancy rate (54.43% vs 57.89%), implantation rate (46.08% vs 49.47%), miscarriage rate (13.95% vs 13.64%) and live birth rate (45.57% vs 48.68%) were not statistically different between the frozen and fresh sperm groups (P > 0.05). In addition, there was no statistical differences in the mean gestational age (38.33weeks ± 1.74 vs 37.89weeks ± 1.87), preterm delivery rate (5.56% vs 10.81%), mean birth weight at delivery (3026.50 g ± 577.64 vs 2977.56 g ± 528.93), and low birth weight (12.50% vs 19.51%) between the two groups (P > 0.05 in all cases). Modified micro cryotube for cryopreservation of rare testicula rretrieved spermatozoa did not negatively affect the pregnancy and neonatal outcomes in TESA-ICSI cycles. The presented method may be a useful alternative for cryopreservation of small numbers of human spermatozoa in clinical setting.

Technologies for Vitrification Based Cryopreservation

Cryopreservation is a unique and practical method to facilitate extended access to biological materials. Because of this, cryopreservation of cells, tissues, and organs is essential to modern medical science, including cancer cell therapy, tissue engineering, transplantation, reproductive technologies, and bio-banking. Among diverse cryopreservation methods, significant focus has been placed on vitrification due to low cost and reduced protocol time. However, several factors, including the intracellular ice formation that is suppressed in the conventional cryopreservation method, restrict the achievement of this method. To enhance the viability and functionality of biological samples after storage, a large number of cryoprotocols and cryodevices have been developed and studied. Recently, new technologies have been investigated by considering the physical and thermodynamic aspects of cryopreservation in heat and mass transfer. In this review, we first present an overview of the physiochemical aspects of freezing in cryopreservation. Secondly, we present and catalog classical and novel approaches that seek to capitalize on these physicochemical effects. We conclude with the perspective that interdisciplinary studies provide pieces of the cryopreservation puzzle to achieve sustainability in the biospecimen supply chain.

A comprehensive review and update on human fertility cryopreservation methods and tools

The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.

Artificial oocyte activation with ionomycin compared with A23187 among patients at risk of failed or impaired fertilization

RESEARCH QUESTION

Do fertilization rates differ between intracytoplasmic sperm injection (ICSI) cycles treated with artificial oocyte activation (AOA) using 10 µmol/l ionomycin or commercial A23187 in women at risk of failed or impaired fertilization?

DESIGN

This single-centre, 7-year retrospective cohort study included 157 couples with a history of total fertilization failure (TFF, 0%) or low fertilization (<30%) after ICSI, or with severe oligo-astheno-teratozoospermia (OAT) in the male partner. Couples and underwent 171 ICSI-AOA cycles using either 10 µmol/l ionomycin or commercial A23187. The embryological and clinical outcomes were compared.

RESULTS

Fertilization rates in the ionomycin group were significantly higher than those in the A23187 group for all three subgroups (TFF, 46.9% versus 28.4%, P = 0.002; low fertilization, 67.7% versus 49.2%, P < 0.001; severe OAT, 66.4% versus 31.6%, P < 0.001). AOA with ionomycin significantly increased the day 3 cleavage rate (P = 0.009) when compared with A23187 in the low fertilization group, but not in the TFF or severe OAT group (both P > 0.05). The rates of day 3 good-quality embryos, clinical pregnancy, implantation and live birth, and the cumulative live birth, did not differ between the two groups (all P > 0.05). A total of 64 live births resulted in 72 healthy babies born.

CONCLUSIONS

AOA with 10 µmol/l ionomycin may be more effective than commercial A23187 in improving oocyte activation in patients at risk of failed or impaired fertilization, especially in cases of sperm-related defects.

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 LSL carriers?

MATERIALS AND METHODS

This study involves ninety-three samples from healthy sperm donors and forty 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 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. This article is protected by copyright. All rights reserved.

Vitrification with microinjection of single seminiferous tubules: an efficient cryopreservation approach for limited testicular tissue

RESEARCH QUESTION

Is vitrification with microinjection of single seminiferous tubules an efficient cryopreservation approach for limited testicular tissue?

DESIGN

Testicular tissue from 10 patients with normal spermatogenesis were assigned to a fresh control group or one of the following cryopreservation procedures: uncontrolled slow freezing (USF) using either 1.5 or 2.1 M DMSO combined with sucrose and vitrification with or without single seminiferous tubules microinjection.

RESULTS

Single seminiferous tubules microinjected with cryoprotective agents (CPA) enhanced the penetration of CPA compared with CPA-treated testicular tissue fragments. Microinjection of seminiferous tubules (VLP) maintained tubule structural integrity and germ cell numbers, and reduced spermatogonial apoptosis after cryopreservation compared with vitrification without microinjection (apoptosis rate: VLP versus vitrification without microinjection, P = 0.047; VLP versus USF, P= 0.049). Freezing of single seminiferous tubules using 0.25-ml straws and traditional sperm freezing methods protected sperm retrieval and recovery rates, and the progressive motility index.

CONCLUSIONS

Vitrification of single seminiferous tubule with microinjection of low CPA concentration is an effective approach to testicular cryopreservation.

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.

ICSI outcomes of fresh or cryopreserved spermatozoa from micro-TESE in patients with nonobstructive azoospermia: CONSORT

The aim of this study was to evaluate intracytoplasmic sperm injection (ICSI) outcomes of fresh and cryopreserved sperm via microdissection testicular sperm extraction (micro-TESE) in patients with nonobstructive azoospermia (NOA).From March 2016 to February 2020, a total of 244 men with NOA underwent micro-TESE at the Center for Reproductive Medicine, First Hospital of Jilin University, P. R. China. These cases included 40 patients who underwent 40 ICSI cycles with fresh spermatozoa from micro-TESE (Group A) and 30 patients who underwent 30 ICSI cycles with cryopreserved spermatozoa from micro-TESE (Group B). The characteristics, embryonic development, and ICSI outcomes of patients were compared between groups A and B.Our sperm retrieval rate (SRR) by micro-TESE in patients with NOA was 35.25%. No statistical differences in the patient characteristics and fertilization or quality embryo rates were observed between Groups A and B. Higher miscarriage rates and lower live births were observed in Group B than in Group A (both P < .05).Fresh testicular spermatozoa seem to produce better ICSI outcomes than cryopreserved testicular spermatozoa from patients with NOA in the micro-TESE-ICSI cycle.

A decellularized oocyte-derived scaffold provides a "sperm safe" to preserve mammalian spermatozoa

BACKGROUND

Although only one spermatozoon is needed to create a zygote, a significant challenge is the storage and recovery of germ cells when sperm counts are extremely low.

OBJECTIVES

We engineered an oocyte-derived biomaterial-the zona pellucida (ZP)-as a "sperm safe" for storing spermatozoon. The ZP is a glycoprotein matrix that surrounds the mammalian oocyte.

MATERIALS AND METHODS

We made a hole in the ZPs using a Piezo drill and mechanically separated them from the oocyte cytoplasm. A subset of ZPs were further purified through decellularization. Using a modified ICSI approach, we injected sperm heads into purified ZPs and tested the efficacy of cryopreservation and recovery of spermatozoon as well as function.

RESULTS

Between 1-6 sperm heads were injected into purified ZPs (average 2.7 ± 1.7 sperm heads/ZP), which were then cryopreserved. Upon thawing, an average of 2.5 ± 1.4 sperm heads/ZP were observed, and in 11 of 12 thawed "sperm safes," we recovered all spermatozoa. Decellularized "sperm safes" maintained their three-dimensional structure and had a denser matrix relative to untreated controls as assessed by scanning and transmitted electron microscopy. The efficacy of "sperm safe" derived spermatozoon was evaluated by ICSI. Spermatozoon stored in either untreated or decellularized "sperm safes" elicited egg activation-associated calcium transients and zinc sparks when injected into eggs. Of the resulting zygotes, >80% of them formed pronuclei irrespective of the sperm source. 26.8 ± 4.6% and 18.1 ± 7.0% of the pre-implantation embryos generated from spermatozoon recovered from untreated or decellularized "sperm safes" developed to the blastocyst stage, respectively. Although this development was lower than that using fresh spermatozoon (59.3 ± 19.3%) or conventionally frozen-thawed spermatozoon (28.4 ± 1.7%), these differences were not significant.

DISCUSSION AND CONCLUSION

Purified ZPs represent a natural biomaterial for the efficient preservation and recovery of small sperm numbers.

Cryopiece, a novel carrier with faster cooling rate, high recovery rate and retrieval rate, for individual sperm cryopreservation

Background

Cryopreservation of extremely few spermatozoa is still a major challenge for male fertility preservation. This study aims to evaluate the cooling rate, recovery rate, and retrieval rate, along with other parameters of spermatozoa that cryopreserved using Cryopiece, a novel carrier, for individual sperm cryopreservation.

Methods

Semen samples from 60 fertile donors were collected, and each semen sample was screened for motile sperm and mixed with cryoprotective agent (CPA), and then frozen using Cryopiece, micro-straw, and mini-straws. The cooling rate, retrieval rate, and recovery rate, morphology, DNA fragmentation index (DFI) and mitochondrial membrane potential (MMP), were compared among the un-frozen sperm and the sperm cryopreserved using these carriers.

Results

Cryopiece possessed the fastest cooling rate. After freeze-thaw, the average retrieval rate of sperm cryopreserved using Cryopiece was 96.25%, and the average recovery rate was 64.40%, which were higher than that of sperm cryopreserved using the other two carriers (71.42% and 54.30% for micro-straw, and 63.54% and 58.04% for mini-straw, respectively). There was no significant impact on DFI after sperm cryopreservation, and no significant difference in morphology between sperm cryopreserved using these carriers was observed. Though MMP of sperm changed significantly after cryopreservation, micro-straw maintained sperm MMP better than Cryopiece and mini-straw did, while no significant difference was observed in MMP between sperm cryopreserved using Cryopiece and mini-straw.

Conclusions

Cryopiece produced satisfying retrieval and recovery rates in sperm cryopreservation and should be an ideal carrier for cryopreservation of small number of sperm.

Modified stepwise mini-incision microdissection testicular sperm extraction: a useful technique for patients with a history of orchidopexy affected by non-obstructive azoospermia

Non-obstructive azoospermia (NOA), which is defined as the absence of spermatozoa in the ejaculate secondary to impaired spermatogenesis within the testis, may be caused by a variety of etiologies, including varicocele-induced testicular damage, cryptorchidism, prior testicular torsion, post-pubertal mumps orchitis, gonadotoxic effects from medications, genetic abnormalities, chemotherapy/radiation, and other unknown causes currently classified as idiopathic (Cocuzza et al., 2013). The microdissection testicular sperm extraction (micro-TESE) technique involves a meticulous microsurgical exploration of the testicular parenchyma to identify and selectively extract larger seminiferous tubules that carry a higher probability of complete spermatogenesis (Schlegel, 1999). The Cornell group evaluated the efficacy of micro-TESE in 152 NOA patients with an associated history of cryptorchidism. In their series, spermatozoa were successfully retrieved in 116/181 attempts (64%), and the resulting pregnancy rate was 50% with a delivery rate of 38% (Dabaja and Schlegel, 2013). Franco et al. (2016) described a stepwise micro-TESE approach in NOA patients, which was considered to reduce the cost, time, and effort associated with the surgery. Alrabeeah et al. (2016) further reported that a mini-incision micro-TESE, carried through a 1-cm equatorial testicular incision, can be useful for micro-TESE candidates, particularly in patients with cryptozoospermia. We conducted a retrospective study of 20 consecutive NOA patients with a history of orchidopexy from May 2015 to March 2017.

Novel micro-straw for freezing small quantities of human spermatozoa

OBJECTIVE

To evaluate a novel micro-straw as an efficient, simple method for freezing a small number of human spermatozoa for intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective cohort study.

SETTING

Sperm bank.

PATIENT(S)

Men with severe oligozoospermia or azoospermia undergoing a total of 143 ICSI cycles at the CITIC-Xiangya Hospital of Reproduction and Genetics from June 1, 2015, to June 31, 2019, and 20 donors at the Hunan Province Human Sperm Bank from 2001 to 2016.

INTERVENTION(S)

Analysis of sperm samples and clinical outcomes after sperm use.

MAIN OUTCOME MEASURE(S)

Clinical information, including number of motile sperm before and after freezing, freeze-thaw survival rates, two-pronuclear fertilization rates, clinical pregnancy, and early pregnancy loss rates after sperm use.

RESULT(S)

In the feasibility experiment using the micro-straw, we found a freeze-thaw survival rate of 73% ± 8.3% and no difference in normal sperm morphology, normal acrosome integrity, or DNA fragmentation index between the micro-straw and 1.8-mL cryotubes. The prospective cohort included 1,325 cases, and we collected sperm from testicular, epididymis, and ejaculation sources. We observed motile sperm in 1,294 (97.6%) of 1,325 frozen-thawed samples. Postthaw sperm were available for ICSI in 140 (97.9%) of 143 of cycles. The fertilization, cleavage, and high-quality embryo rates were 1,007 (81.7%) of 1,233; 995 (98.8%) of 1,007; and 537 (53.9%) of 995, respectively. Sixty-nine (49%) clinical pregnancies were achieved, and the miscarriage rate was 6 (8.6%) of 69.

CONCLUSION(S)

The micro-straw is suitable and clinically useful for the cryopreservation of small numbers of spermatozoa.

ART strategies in Klinefelter syndrome

PURPOSE

Patients with Klinefelter syndrome (KS) who receive assisted reproductive technology (ART) treatment often experience poor pregnancy rates due to decreased fertilization, cleavage, and implantation rates and even an increased miscarriage rate. Mounting evidence from recent studies has shown that various technological advances and approaches could facilitate the success of ART treatment for KS patients. In this review, we summarize the methods for guiding KS patients during ART and for developing optimal strategies for preserving fertility, improving pregnancy rate and live birth rate, and avoiding the birth of KS infants.

METHODS

We searched PubMed and Google Scholar publications related to KS patients on topics of controlled ovarian stimulation protocols, sperm extraction, fertility preservation, gamete artificial activation, round spermatid injection (ROSI), and non-invasive prenatal screening (PGD) methods.

RESULTS

This review outlines the different ovulation-inducing treatments for female partners according to the individual sperm status in the KS patient. We further summarize the methods of retrieving sperm, storing, and freezing rare sperm. We reviewed different methods of gamete artificial activation and discussed the feasibility of ROSI for sterile KS patients who absolutely lack sperm. The activation of eggs in the process of intracytoplasmic sperm injection and non-invasive PGD are urgently needed to prevent the birth of KS infants.

CONCLUSION

The integrated strategies will pave the way for the establishment of ART treatment approaches and improve the clinical outcome for KS patients.

Studies on the basic issues relevant to sperm cryopreservation in humans

Rapid freezing and vitrification are becoming popular for sperm freezing in humans; however, basic and critical issues relevant to sperm cryopreservation remain to be resolved. The aims of the present study were to study the effects of osmolality of freezing medium, sperm concentrations, thawing methods, and sugars (sucrose and trehalose) on sperm motility and DNA integrity by rapid freezing using 0.5 ml standard straws loaded with 100 µl sperm each. The results showed that (1) the post-thaw recovery rates of total motility and progressive motility of sperm cryopreserved in freezing medium containing 0.25 M sucrose with 442 mOsm/kg osmolality were significantly higher (p < 0.05) than that of sperm cryopreserved in freezing medium containing 0.25 M sucrose with 536 mOsm/kg osmolality (36.5 ± 2.8% and 36.9 ± 1.7% versus 30.4 ± 1.9% and 30.3 ± 2.9%, respectively), (2) cryopreservation of both total and progressive motilities was not significantly affected (p > 0.05) by sperm concentrations in the range from 5 to 20 × 10⁶ sperm/ml, (3) thawing method 37°C for 2 min was better than 42°C for 15 s in terms of post-thaw recovery rates of both total and progressive motilities (p < 0.05), (4) 0.25 M trehalose was better than 0.25 M sucrose in cryopreserving both total and progressive motilities (p < 0.05), and (5) sperm nuclear DNA is relatively resistant to the changes of the above factors compared with sperm motility. It was concluded that human sperm can be best cryopreserved by rapid freezing using 0.25 M sucrose or trehalose with osmolality 442 to 457 mOsm/kg at high sperm concentration followed by thawing at 37°C. Trehalose is a stronger cryoprotectant than sucrose for sperm cryopreservation.

Human sperm vitrification: the state of the art

Sperm cryopreservation has been widely used in assisted reproductive technology (ART) and has resulted in millions of live births. Two principal approaches have been adopted: conventional (slow) freezing and vitrification. As a traditional technique, slow freezing has been successfully employed and widely used at ART clinics whereas the latter, a process to solidify liquid into an amorphous or glassy state, may become a faster alternative method of sperm cryopreservation with significant benefits in regard to simple equipment and applicability to fertility centers. Sperm vitrification has its own limitations. Firstly, small volume of load is usually plunged to liquid nitrogen to achieve high cooling rate, which makes large volume sample cryopreservation less feasible. Secondly, direct contact with liquid nitrogen increases the potential risk of contamination. Recently, new carriers have been developed to facilitate improved control over the volume and speed, and new strategies have been implemented to minimize the contamination risk. In summary, although sperm vitrification has not yet been applied in routine sperm cryopreservation, its potential as a standard procedure is growing.

Sequential interval micro-droplet loading in closed hemi-straw carrier system: A convenient and efficient method for ultra-rapid cryopreservation in extreme oligozoospermia

Cryopreservation of human spermatozoa with low concentration while maintaining adequate post-thawing motility remains a major challenge for male fertility preservation. A convenient and efficient ultra-rapid freezing method for small amounts of human spermatozoa in a closed Hemi-Straw carrier system (CHS) was developed. Spermatozoa from 60 healthy men were involved in a parameter refining test and another 15 extreme oligozoospermic specimens were assigned to a verification test. A commercialized sperm freezing medium, Quinn's Advantage® Sperm Freeze medium (glycerol and sucrose as the cryoprotective agent) was used in the study. The results showed that the highest recovery rates would be obtained via the method of 2 μl single droplet sequential interval loading, by placing the straw at 1 cm above the liquid nitrogen (LN₂) surface for 60 s during freezing and 2 cm above the LN₂ for 2 min during thawing. This method was applied in cryopreservation for the normozoospermic specimens and compared with a conventional slow freezing method. The results were better than those in the control group in the total motility recovery rate (77.8 ± 11.2% vs 56.6 ± 11.9%, P < 0.01), progressive motility recovery rate (77.6 ± 13.2% vs 47.7 ± 14.6%, P < 0.01), 24 h survival index (60.9 ± 13.4% vs 42.1 ± 14.1%, P < 0.01) and the sperm DNA fragment index (4.2 ± 3.7% vs 5.8 ± 3.7%, P = 0.126). This method was applied to the oligozoospermic specimens. Motile spermatozoa could be found in 12 of 15 cases in the ultra-rapid freezing group, while only in 7 cases in control group. The results indicated that this freezing method was simple, convenient and bio-safe for cryopreservation of severe oligozoospermic specimens.

Evaluation and improvement of the novel method for vitrification of a few human sperms

RESEARCH QUESTION

The purposes of this study are to evaluate the performance of the novel SpermVD device on vitrification of a few human sperms, and determine whether PICSI dish and density gradient centrifugation can improve the quality of sperm after thawing.

DESIGN AND METHODS

In order to determine the suitable preparation methods, both washed sperm and neat sperm were selected in ICSI dish and PICSI dish, and frozen with the novel SpermVD device. The selected sperms were transferred to freezing droplets with 1 μl droplet of a 50/50 v/v mixture of QA Sperm Freezing Medium and QA Medium w/Hepes on the SpermVD wells. And the device was exposed to vapor of liquid nitrogen for 5 min and then placed into LN₂ immediately. The sperms were thawed in a 37℃ oil filled dish which contained QA Medium w/Hepes droplets and they were searched and revaluated immediately. The frozen effects of sperm were evaluated by progressive motility, motility, viability and recovery rates of freezing-thawing sperm.

RESULTS

After freezing-thawing, the overall sperm recovery rate was 94.2% with 70% viability, 20.7% progressive motility, and 36.2% motility. The progressive motility, motility, viability and recovery rates of washed sperm were lower than that of the neat sperm, with a significant difference (P <  0.01) at both viability and motility rates. In addition, the viability rate was significantly higher in PICSI dish group than that of ICSI dish group (P <  0.01) and the motility, recovery and progressive motility rates were not significantly different between the two groups (P > 0.05).

CONCLUSIONS

The spermVD device was one of the effective platforms for freezing a few human sperms and using PICSI dish to select mature neat sperms could improve the quality of sperm after thawing. Density gradient centrifugation might be not required or suitable sperm preparation methods before freezing.

Outcome of Oocyte Vitrification Combined with Microdissection Testicular Sperm Extraction and Aspiration for Assisted Reproduction in Men

Background

As a safety and efficacy protocol, oocyte vitrification has been widely used in IVF treatment. The aim of this study was to evaluate the outcome of ICSI-ET utilizing vitrified oocytes with sperm obtained from non-obstructive azoospermia (NOA) patients via micro-TESE.

Material/Methods

A total of 150 NOA patients underwent micro-TESE. Ten patients were unable to ejaculate and refused to accept TESA at the time of oocyte retrieval; later, these patients underwent TESA. A total of 174 obstructive azoospermia (OA) patients underwent TESA. Vitrified oocytes were used with micro-TESE in 35 cycles (group 1), and TESA in 10 cycles (group 2). Fresh oocytes were used with micro-TESE in 38 cycles (group 3) and TESA in 174 cycles (group 4).

Results

The overall sperm retrieval rate of the 150 NOA patients was 48.7% (73/150). A total of 257 cycles of ICSI-ET were conducted with testicular spermatozoa; 212 cycles utilized fresh oocytes and 45 cycles utilized vitrified oocytes. No differences were observed with fertilization (73.8%, 77.2%,72.8%, 73.6%), implantation (33.3%, 34.7%, 33.8%, 37.5%), or clinical pregnancy rates (51.4%, 60%, 52.6%, 51.7%) for groups 1 through 4, respectively (P>0.05). Developmental competence was greatest among couples using sperm obtained via TESA rather than micro-TESE, not dependent on whether vitrified or fresh oocytes were utilized. Fertilization, implantation, and clinical pregnancy rates did not differ between using fresh vs. vitrified oocytes, nor did they differ between using testicular sperm derived from men with NOA vs. men with OA.

Conclusions

Vitrified oocytes combined with micro-TESE showed similar clinical efficacy when compared with fresh oocytes.

A new insight into male fertility preservation for patients with completely immotile spermatozoa

BACKGROUND

Sperm cryopreservation is the most effective method to preserve male fertility but this is normally used for motile spermatozoa. Thus, only motile spermatozoa are used for cryopreservation in most reproductive medicine centers worldwide. The immotile spermatozoa from some problematic patients are usually discarded, resulting in a missed opportunity of sterility cryopreservation for future assisted reproductive treatments. Many studies have shown that successful fertilization can be obtained after selection of viable sperm from the completely immotile spermatozoa before ICSI. Whether the completely immotile spermatozoa are worth of freezing has not been realized The aim of this study is to explore the clinical value of cryopreservation of immotile spermatozoa.

METHODS

Completely immotile spermatozoa were collected and frozen, and subsequently viable but immotile frozen-thawed spermatozoa were selected by laser plus for ICSI. Main outcomes included spermatozoa survival index, fertilization rate and good quality embryo rate.

RESULTS

After identification by laser, the fresh samples of spermatozoa presented with a mean survival rate of 54.86% and 26.05%, and this was reduced to 44.13% and 18.13% in frozen-thawed spermatozoa samples, which showed a frozen-thawed spermatozoa survival index of 0.80 and 0.70 in the testicular and ejaculate sperm, respectively. There were no statistically differences in fertilization rate (80% vs80.51%, 75.00% vs 81.48%), cleavage rate (95.45% vs 98.95%, 100.00% vs 95.45%) and good quality embryo rate (40.48% vs 52.13%, 33.33%vs38.10%) between the frozen-thawed immotile spermatozoa group and the routine fresh immotile spermatozoa ICSI group in both testicular and ejaculate sperm, respectively.

CONCLUSIONS

The results of the study show that completely immotile spermatozoa can be frozen in order to preserve male fertility as long as viable spermatozoa are present. This procedure provides a further possibility for fertility preservation for patients with completely immotile spermatozoa.