Cryopreservation Of Gametes Research Articles

Gonadal Failure and Infertility in Cancer Survivors: Clinical Management and Strategies for Prevention.

Modern advances in oncological treatments determined a significant improvement in survival rates for several malignancies. Nevertheless, survivorship and quality of life of cancer survivors may be negatively impaired by metabolic and endocrine side effects related to anticancer treatments, including alterations of pituitary-gonadal axis function. In fact, both medical (chemo- and radiotherapy) and surgical approaches may negatively impact on gonadal function, leading to transient or permanent hypogonadism and infertility. In view of these considerations, fertility preservation (FP) should be a primary concern in all oncological patients who may potentially achieve parenthood, irrespectively from their sex and pubertal status at treatment, and adequate counselling should be provided before undergoing gonadotoxic therapy or gonadectomy. Cryopreservation of gametes, when feasible, represents the mainstay for FP in postpubertal age, while procedures involving storage of tissue specimens or stem cells should still be considered as experimental. Given the complexity of both hormonal and psychological implications in this clinical setting, a multidisciplinary approach is advisable for optimal FP and for early diagnosis and treatment of hypogonadism.

Generation of reproductively mature offspring from the endangered green and golden bell frog Litoria aurea using cryopreserved spermatozoa.

Amphibians are becoming increasingly reliant on captive breeding programs for continued survival. Assisted reproductive technologies including gamete cryopreservation and IVF can help reduce costs of breeding programs, provide insurance against extinction and assist genetic rescue in wild populations. However, the use of these technologies to produce reproductively mature offspring has only been demonstrated in a few non-model species. We aimed to optimise sperm cryopreservation in the threatened frog Litoria aurea and generate mature offspring from frozen-thawed spermatozoa by IVF. We tested three concentrations (1.4, 2.1 and 2.8M) of the cryoprotectants dimethylsulfoxide (DMSO) and glycerol with 0.3M sucrose. Using DMSO was more likely to result in recovery of sperm motility, vitality and acrosome integrity than glycerol, regardless of concentration, with forward progressive motility being most sensitive to damage. The lowest concentrations of 1.4 and 2.1M provided the best protection regardless of cryoprotectant type. Spermatozoa cryopreserved in 2.1M DMSO outperformed spermatozoa cryopreserved in equivalent concentrations of glycerol in terms of their ability to fertilise ova, resulting in higher rates of embryos hatching and several individuals reaching sexual maturity. We have demonstrated that sperm cryopreservation and subsequent offspring generation via IVF is a feasible conservation tool for L. aurea and other threatened amphibians.

Can COVID-19 Be Transmitted Sexually by Semen?

Information on the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has amplified quickly since its spread; however, many issues remain unclear. SARS-CoV-2 is mainly transmitted through respiratory secretions. However, the potential for SARS-CoV-2 sexual transmission by semen is worthy of study. The cell-receptors of SARS-CoV-2, the angiotensin-converting enzyme-2 receptors, are highly expressed in human testis and may enable this virus to cause testicular tissue damage with bad effect on male fertility. SARS-CoV-2 presentation ranges from asymptomatic carriage to acute respiratory distress and fatal pneumonia, and elderly persons with underlying comorbidities usually suffer from a severe clinical picture. Asymptomatic individuals can spread the virus through their respiratory secretions and possibly through sexual transmission. SARS-CoV-2 can persist viable if cryopreserved in semen samples in sperm cryobankes. As far as I know, there is a gap in knowledge about SARS-CoV-2 transmission through semen, indicating the need for further research. This review attempts to understand the SARS-CoV-2 sexual transmission by semen. One recent study confirmed the theoretical risk of SARS-CoV-2 transmission by semen, but few studies negate this theory. Given that, an increasing number of asymptomatic and reactivated SARS-CoV-2 cases are being reported, attention to semen safety and SARS-CoV-2 transmission should be considered particularly in high-risk areas, to ensure the safety of male gametes for artificial reproduction and the general public. Avoiding cryopreservation of male gametes, condom use or even abstinence might be of paramount importance for these persons.

PROSPECTS OF APPLICATION OF ARTIFICIAL FERTILIZATION FOR OBTAINING PIG EMBRYOS IN VITRO

Literary data about the method using artificial insemination for receiving pigs’ embryos in vitro (intracytoplasmic injection spermatozoon in oocyte (ICSI – Intracytoplasmic sperm injection)) for application of such approach to preserve and improve the gene pool of domestic pig breeds were presented.
 In pig breeding there is a threat of extinction of breeds due to periodic outbreaks of infectious diseases. Scientists are constantly paying attention to the preservation of the gene pool of this species, but approaches to cryopreservation of gametes and embryos still do not provide stable and high results. Some biotechnological manipulations were only informative, although practical approaches to gene pool conservation are essential.
 The ICSI method is an artificial insemination of oocytes in vitro during which one spermatozoon is injected into a mature oocyte at the stage of metaphase II meiosis. It is currently well established on female oocytes, but for oocytes of other mammalian species remains insufficiently optimized to achieve the same percentage of fertilization and embryo formation. In our country there is very little data on the use of ICSI method for artificial insemination of animals, including pigs, although this method will increase the efficiency of fertilization and the formation of full-fledged pig embryos in vitro.
 It was shown that the level of blastocyst formation in pigs that were cleaved from thawed immature oocytes fertilized by ICSI was 5.2%.
 It has been proven that the efficiency of fertilization by a modified ICSI method increases when using hyaluronic acid for sperm selection called PICSI. Because only mature sperm have a receptor for hyaluronic acid, which is contained on the zona pellucida of the oocyte, so only mature spermatozoa are selected for fertilization.
 It has long been thought that damage to the head of the sperm leads to damage to the genetic material, which in turn leads to lack of fertilization or the formation of abnormal embryos. Therefore, among the requirements for ICSI the main was the damage of the tail and avoidance of the sperm head and neck injury. Disulfide bridges of the sperm head, which are formed through the passage through the epididymis, have been shown to make the sperm nucleus resistant to chemical and physical ruptures.
 Chinese scientists published in 2020 the results of studies on the treatment of oocytes during the ICSI procedure with urhodeoxycholic acid and showed that this approach increases the percentage of zygotes obtained. This phenomenon is explained by the ability of this substance to reduce oxidative stress caused during this procedure in the endoplasmic reticulum and prevent apoptosis.
 Thus, the ICSI method provides effective fertilization with the involvement of a minimum number of sperm, which is extremely convenient in working with extinct species and species that are on the verge of extinction.
 Our data on the application of the ICSI method with various modifications indicate the prospects for the application of the ICSI method for its implementation in practice.

The Evolution of the Cryopreservation Techniques in Reproductive Medicine—Exploring the Character of the Vitrified State Intra- and Extracellularly to Better Understand Cell Survival after Cryopreservation

Nowadays, cryopreservation of gametes and embryos is a fundamental, integral, and indispensable part of infertility treatment or fertility preservation. Cryopreservation is not only needed for the policy of single embryo transfer and cryopreservation of surplus embryos, but for deferring embryo transfer in the case of ovarian hyperstimulation syndrome, uterine pathologies, and suboptimal endometrium built-up or when preimplantation genetic testing is needed. Several current strategies in assisted reproduction technology (ART) would be inconceivable without highly efficient cryopreservation protocols. Nevertheless, cryopreservation hampered for a long time, especially in terms of low survival rates after freezing and thawing. Only the technical progress during the last decades, namely, in regard to the implementation and advancement of vitrification, leveraged its application, and thus, even allows the cryopreservation of human oocytes—a process that is far from being easy. This review aims to provide a deeper insight into the physical processes of cryopreservation and to explore the character of the vitrified state in the extra and intracellular milieu in order to demonstrate that the common denominator to all cryopreservation procedures is the establishment of an intracellular amorphous condition that hinders the likelihood of crystallization.

Sperm quality parameters of Iberian toothcarp (Aphanius iberus) and Valencia toothcarp (Valencia hispanica): New conservation tools from a gamete perspective

The sensitive state of conservation of several endemic fish species such as Iberian toothcarp (Aphanius iberus) and Valencia toothcarp (Valencia hispanica) has led governments to consider the implementation of conservation measures to preserve their populations. However, limited knowledge about the reproductive biology of these species makes it necessary to investigate different aspects of their reproductive cycle. In this sense, the main objectives of this work were i) to advance knowledge of the breeding biology of both species, and ii) to develop protocols for the conservation of gametes for the future management and conservation.During the spring of 2019 a temporal series of samplings were carried out in different places in the Comunitat Valenciana. Sperm samples were collected and sperm motion parameters were assessed for the first time in both species. Kinetic patterns were similar showing high motility and velocity values during the first 30 s, and a rapid decrease from that point. At the same time, an in-depth morphometric analysis was carried out using computer-assisted sperm analysis software. Spermatozoa from A. iberus and V. hispanica showed similar sizes and shapes to other external fertilizers belonging to Cyprinodontiformes, with small spherical heads, uniflagellated and without acrosomes.In addition, a new cryopreservation protocol was designed for cryobanking the sperm of these threatened species. Cryopreserved samples showed lower motility than fresh samples but reaching acceptable percentages of motile cells after thawing of around 20 and 25% (A. iberus and V. hispanica, respectively). This study is the first of its kind to successfully achieve gamete cryopreservation of these two endemic and endangered species from the Iberian Peninsula, providing new and useful tools to complement the management and conservation programs that are being developed for both species.

Effects of slow freezing and vitrification on embryo development in domestic cat.

Cryopreservation of gametes and embryos is used to maintain genetic diversity of domestic and wild felids. However, felid oocytes and preimplantation embryos contain large amount of intracellular lipids, which affect their cryosensitivity. The objective was to compare the effects of slow freezing and vitrification and to study lipid phase transition (LPT) during cooling in cat embryos. In vitro-derived embryos were cultured 48hr up to 4-8 cell stage, thereafter were either slow frozen or vitrified. Propylene glycol (PG) alone was used as a cryoprotective agent (CPA) for slow freezing, and a mixture of PG and dimethyl sulfoxide (DMSO) were used as CPAs for vitrification. After thawing/warming, embryos were in vitro cultured additionally for 72hr. The total time of in vitro culture was 120hr for all the groups including non-frozen controls. Effects of both cryopreservation procedures on the subsequent embryo development and nuclear fragmentation rate in embryonic cells were compared. There was no significant differences among the percentages of embryos achieved morula and early blastocyst stage in frozen-thawed group (36.4% and 20.0%), in vitrified-warmed group (34.3% and 28.6%) and in controls (55.6% and 25.9%). Cell numbers as well as nuclear fragmentation rate did not differ in these three groups. Average lipid phase transition (LPT) temperature (T*) was found to be relatively low (-2.2±1.3°C) for the domestic cat embryos. It is supposed that the low LPT of LDs may provide a good background for successful application of slow freezing to domestic cat embryos. Generally, our study indicates that slow freezing and vitrification are both applicable for domestic cat embryo cryopreservation.

Vitrification-induced activation of lysosomal cathepsin B perturbs spindle assembly checkpoint function in mouse oocytes.

As the age of child-bearing increases and correlates with infertility, cryopreservation of female gametes is becoming common-place in ART. However, the developmental competence of vitrified oocytes has remained low. The underlying mechanisms responsible for reduced oocyte quality post-vitrification are largely unknown. Mouse cumulus-oocyte complexes were vitrified using a cryoloop technique and a mixture of dimethylsulphoxide, ethylene glycol and trehalose as cryoprotectants. Fresh and vitrified/thawed oocytes were compared for chromosome alignment, spindle morphology, kinetochore-microtubule attachments, spindle assembly checkpoint (SAC) and aneuploidy. Although the majority of vitrified oocytes extruded the first polar body (PB), they had a significant increase of chromosome misalignment, abnormal spindle formation and aneuploidy at metaphase II. In contrast to controls, vitrified oocytes extruded the first PB in the presence of nocodazole and etoposide, which should induce metaphase I arrest in a SAC-dependent manner. The fluorescence intensity of mitotic arrest deficient 2 (MAD2), an essential SAC protein, at kinetochores was reduced in vitrified oocytes, indicating that the SAC is weakened after vitrification/thawing. Furthermore, we found that vitrification-associated stress disrupted lysosomal function and stimulated cathepsin B activity, with a subsequent activation of caspase 3. MAD2 localization and SAC function in vitrified oocytes were restored upon treatment with a cathepsin B or a caspase 3 inhibitor. This study was conducted using mouse oocytes, therefore confirming these results in human oocytes is a prerequisite before applying these findings in IVF clinics. Here, we uncovered underlying molecular pathways that contribute to an understanding of how vitrification compromises oocyte quality. Regulating these pathways will be a step toward improving oocyte quality post vitrification and potentially increasing the efficiency of the vitrification program.

SARS-CoV-2 pandemic and repercussions for male infertility patients: A proposal for the individualized provision of andrological services.

The prolonged lockdown of health facilities providing non‐urgent gamete cryopreservation—as currently recommended by many reproductive medicine entities and regulatory authorities due to the SARS‐CoV‐2 pandemic will be detrimental for subgroups of male infertility patients. We believe the existing recommendations should be promptly modified and propose that the same permissive approach for sperm banking granted for men with cancer is expanded to other groups of vulnerable patients. These groups include infertility patients (eg, azoospermic and cryptozoospermic) undergoing medical or surgical treatment to improve sperm quantity and quality, as well as males of reproductive age affected by inflammatory and systemic auto‐immune diseases who are about to start treatment with gonadotoxic drugs or who are under remission. In both scenarios, the “fertility window” may be transitory; postponing diagnostic semen analysis and sperm banking in these men could compromise the prospects of biological parenthood. Moreover, we provide recommendations on how to continue the provision of andrological services in a considered manner and a safe environment. Our opinion is timely and relevant given the fact that fertility services are currently rated as of low priority in most countries.

Controversies Regarding Ovarian Suppression and Infertility in Early Stage Breast Cancer.

A common side effect of chemotherapy in breast cancer is early menopause in premenopausal patients, which is mainly a result of an indirect form of ovarian ablation, and is associated with substantial impairment of quality of life. Suppressing the production of ovarian estrogen has been shown to reduce the recurrence of hormone receptor-positive early breast cancer in premenopausal women, but whether it has an added advantage over tamoxifen is being discussed. Types of permanent ablation of the ovarian function include surgical oophorectomy and radiation-induced ovarian failure. Both are associated with similar response rates in hormone receptor-positive metastatic breast cancer. Medical castration with luteinizing hormone-releasing hormone analogs (LHRHa) has the benefit of being a reversible approach. Another advantage that premenopausal patients who wish to reduce the risk of developing premature ovarian insufficiency induced by chemotherapy may be offered LHRHa irrespective of whether they desire pregnancy and their age at diagnosis. This also helps reduce the risk of menopausal signs and symptoms as well as the loss of bone density in the long-term, which are primary concerns for women. This is of utmost importance to premenopausal women who do not want to conceive after treatment or are not candidates for fertility preservation strategies because of age. It should be emphasized that for women who are interested in fertility preservation, gamete cryopreservation remains the first option, and LHRHa is not an alternative. During chemotherapy, however, temporary ovarian suppression with LHRHa may be given to women who either have no access to a fertility clinic or who have declined chemotherapy or have contraindications.

Managed wildlife breeding-an undervalued conservation tool?

Knowledge of and the technologies and resources applied to the ex situ care for wildlife have improved greatly in recent years. This has resulted in numerous successes bringing back populations from the brink of extinction by the reintroduction or restoration of animals from conservation breeding programmes. Controlled breeding of wildlife by humans is discussed controversially in society and in scientific circles and it faces a number of significant challenges. When natural breeding fails, Assisted Reproduction Technologies (ART) have been postulated to increase reproductive output and maintain genetic diversity. Furthermore, technical advances have improved the potential for successful collection and cryopreservation of gametes and embryos in many wildlife species.With the aim of creating a better understanding of why ex situ and in situ conservation of threatened species must complement each other, and under which circumstances ART provide additional tools in the rescue of a threatened population, we elucidate the current situation here by using as examples three different megavertebrate families: elephantidae, rhinoceridae and giraffidae.These mammal families consist of charismatic species, and most of their members are currently facing dramatic declines in population numbers. On the basis of these and other examples, we highlight the importance of captive zoo and other managed wildlife populations for species survival in a human dominated world. Without the possibility to study reproductive physiology in trained or habituated captive individuals, major advances made in wildlife ART during the past 20 years would not have been possible. This paper reviews the benefits and future challenges of large mammal conservation breeding and examines the role of assisted reproduction in such efforts.

New directions in assisted breeding techniques for fish conservation.

Fish populations continue to decline globally, signalling the need for new initiatives to conserve endangered species. Over the past two decades, with advances in our understanding of fish germ line biology, new exsitu management strategies for fish genetics and reproduction have focused on the use of germ line cells. The development of germ cell transplantation techniques for the purposes of propagating fish species, most commonly farmed species such as salmonids, has been gaining interest among conservation scientists as a means of regenerating endangered species. Previously, exsitu conservation methods in fish have been restricted to the cryopreservation of gametes or maintaining captive breeding colonies, both of which face significant challenges that have restricted their widespread implementation. However, advances in germ cell transplantation techniques have made its application in endangered species tangible. Using this approach, it is possible to preserve the genetics of fish species at any stage in their reproductive cycle regardless of sexual maturity or the limitations of brief annual spawning periods. Combining cryopreservation and germ cell transplantation will greatly expand our ability to preserve functional genetic samples from threatened species, to secure fish biodiversity and to produce new individuals to enhance or restore native populations.

Reproductive Injustice and the Politics of Trans Future in France

Abstract This article tackles the issue of trans futures through a critical discussion of trans reproductive injustice in France. Most notably, it focuses on one of its many facets: the cisnormative administration of publicly funded gamete cryo-preservation. For a long time trans people in France have been excluded from the possibility of banking their gametes. Only recently the situation is starting to change, but the right of all trans people to cryo-preserve their gametes is far from being fully recognized. The first part of the article traces the genealogy of the exclusion of trans people from gamete cryo-preservation by offering some historical background of the necropolitical governance of trans reproduction in France. The second part explores in detail a public controversy over trans gamete cryo-preservation that emerged in 2013. Through a close reading of this controversy, the article tackles the discursive and material underpinnings of this cisnormative regulation of gamete cryo-preservation.

Amphibian conservation using assisted reproductive technologies: Cryopreserved sperm affects offspring morphology, but not behavior, in a toad

With increasing rates of global biodiversity decline, strategies such as reintroduction or supplementation, have become increasingly important in conserving our remaining biodiversity. To sustain reintroduction programs, insurance colonies are established and bred in captivity. Captive-bred offspring are then released to augment wild populations or establish new populations. A key issue determining the success of reintroduction programs, therefore, is the fitness of captive-bred individuals and their ability to survive once released. Unfortunately, little is known about the quality of captive-bred offspring produced using assisted reproductive technologies, such as gamete cryopreservation. To fill this gap in scientific knowledge and conservation practice, we examined differences in tadpole morphology, tadpole behavior, metamorph morphology, and duration of larval stage between Fowler's toad (Anaxyrus fowleri) offspring produced using cryopreserved sperm (experimental, cryo-derived individuals) and offspring produced by amplectant adults (control individuals). Results indicated cryo-derived individuals were smaller as tadpoles and emerged as smaller metamorphs. However, predator-avoidance behavior was not significantly different between the two treatment groups. Smaller body size in cryo-derived individuals can negatively affect their post-release survivorship and reproductive output, thus limiting the potential success of reintroduction programs. This pioneering study provides insights into the quality and competency of individuals produced using cryopreserved sperm across two distinct life-stages. We show that although cryopreservation has often been proposed as a promising way of contributing to wildlife conservation, more detailed examinations are needed to assess the quality of offspring produced for it to be an effective conservation tool.

THE EVALUATION OF THE EFFICIENCY OF THE CRYOPRESERVATION OF HUMAN'S GAMETES AND EMBRYOS IN ASSISTED REPRODUCTIVE TECHNOLOGY PROGRAM

Cryopreservation of gametes and embryos is the essential of modern reproductive medicine. This study aimed to evaluate the efficiency of the native and frozen material in the assisted reproductive technology programs. We investigated 120 semen samples of healthy males (sperm donors). One hundred cases (83%) demonstrate mobility attenuation after defrosting from 67% to 84% versus initial value. During the investigation of 35 native and 23 frozen oocytes, we taped an insignificant decreasing of cleavage rate (from 98,4% to 84,2%, p=0,018). We performed 1289 defrosted gametes and embryos transfers and used closed (n=611, CryoTip, USA) and open (n=678, CryoTop, Japan) type carriers. The majority of indicators was better when we used open type carriers: survival (84,8% for closed type, 95,1% for open type, p <0,0001), pregnancy rate (39,5%, 44,2%, p=0,001), labors rate (72,7%, 67,3%, p=0,003), losses rate (27,3%, 24,3%, p=0,044). The obtained data allow us to conclude that the vitrification of morphologically normal gametes doesn't deteriorate the efficiency of cryo-program and keeps their reproductive status. Open type carriers for vitrification and storage of embryos demonstrates higher survival of embryos, pregnancy rate and lower losses rate after cryopreservation as compared to closed type carriers. Highly likely it occurs due to direct contact of an embryo with liquid nitrogen and high freezing speed. It can be the crucial factor defining the success of the vitrification in open type carriers.

Overexpression of Mitochondrial Genes (Mitochondrial Transcription Factor A and Cytochrome c Oxidase Subunit 1) in Mouse Metaphase II Oocytes following Vitrification via Cryotop.

Background: Gamete cryopreservation is an inseparable part of assisted reproductive technology, and vitrification is an effective approach to the cryopreservation of oocytes. The aim of this study was to investigate vitrification effects on the expression levels of mitochondrial transcription factor A (Tfam) and mitochondrial-encoded cytochrome c oxidase subunit 1 (Cox1) in mouse metaphase II oocytes. Methods:Oocytes were selected by simple random sampling and distributed amongst five experimental groups (control [n=126], docetaxel [n=132], docetaxel+cryoprotectant agent [CPA] [n=134], docetaxel+vitrification [n=132], and vitrification [n=123]). After the warming process, the oocytes were fertilized and cultured into a 2-cell stage. Then, the effects of vitrification on the expression of the Tfam and Cox1 genes were determined via real-time reverse transcriptase polymerase chain reaction. Each group was compared with the control group. The data were analyzed with ANOVA using GraphPad and SPSS, version 21. Results:A significant decrease was observed in the fertilization rate of each group in comparison with the control group (P=0.001). The rate of 2-cell formation after in vitro fertilization was significantly lower in both vitrification groups (docetaxel+vitrification and vitrification) than in the non-vitrification groups (fresh control and docetaxel) and control group (P=0.001 and P=0.004). The expression level of Cox1 was significantly higher in the vitrification group than in the control group (P=0.01), while it was lower in the docetaxel group than that in the control group (P=0.04). The expression level of the Tfam gene was significantly high in the vitrification group (vitrification+docetaxel) and the non-vitrified group (docetaxel+CPA) in comparison with the control group (P=0.01). Conclusion:This study indicated that the vitrification of mouse MII oocytes increased the expression of the Tfam and Cox1 genes.

Cryopreservation of both male and female gametes leads to reduced embryo development and implantation potential

Cryopreservation of both male and female gametes leads to reduced embryo development and implantation potential

Out of the Freezer and into the Policy Fire: Quandaries in Reproductive Cryopreservation.

The field of assisted reproduction is advancing rapidly and is ripe for regulation and guidance. In 2018, over four thousand frozen eggs and embryos were lost to approximately one thousand patients at Ahuja University Hospital in Cleveland, Ohio, due to an accidental thaw of a cryopreservation tank. The precedent that will be set by the Ahuja class-action case is significant for both past events and future possibilities and is core to the discussion of policy involving the cryopreservation of gametes and embryos.

Oocyte Retrieval during Laparoscopic Vaginoplasty to Reduce Invasiveness in the Treatment of Mayer-Rokitansky-Küster-Hauser Syndrome

To evaluate the treatment of patients with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome with a combination of oocyte retrieval and surgical vaginoplasty in a single laparoscopic procedure. A case series. The study was conducted at 2 tertiary referral facilities for MRKH syndrome in Milan, Italy, between July 2017 and September 2018. Eleven patients presented with MRKH and required surgical vaginoplasty while expressing a desire for future fertility. Two experienced surgeons and an expert in assisted reproductive technology performed concomitant vaginoplasty according to the modified technique of Davydov and laparoscopic oocyte retrieval for gamete cryopreservation. Before the procedure, patients underwent extensive counseling and gave written consent. At the start of surgery, 10.4 ± 4.4 (mean ± standard deviation [SD]) oocytes were retrieved laparoscopically, and 8.8 ± 3.1 (SD) mean mature oocytes were cryopreserved. After oocyte retrieval, the steps of the modified Davydov technique were followed. The total operative time was 116 ± 16 minutes (mean ± SD), and no intraoperative/postoperative complications were observed. This is the first report of combined oocyte retrieval and vaginoplasty for patients with MRKH syndrome. The approach was found to be feasible in patients with a desire for future fertility. It is our belief that physicians treating patients with MRKH should refer patients to centers with expertise in both vaginoplasty and assisted reproductive technology.

The Use of Antifreeze Proteins in the Cryopreservation of Gametes and Embryos.

The cryopreservation of gametes and embryos is a technique widely used in reproductive biology. This technology helps in the reproductive management of domesticated animals, and it is an important tool for gene banking and for human-assisted reproductive technologies. Antifreeze proteins are naturally present in several organisms exposed to subzero temperatures. The ability for these proteins to inhibit ice recrystallization together with their ability to interact with biological membranes makes them interesting molecules to be used in cryopreservation protocols. This mini-review provides a general overview about the use of antifreeze proteins to improve the short and long term storage of gametes and embryos.