Fertility preservation in patients with non-oncological conditions

The Role of Stem Cells and Their Derived Extracellular Vesicles in Restoring Female and Male Fertility

Infertility is a globally recognized issue caused by different reproductive disorders. To date, various therapeutic approaches to restore fertility have been attempted including etiology-specific medication, hormonal therapies, surgical excisions, and assisted reproductive technologies. Although these approaches produce results, however, fertility restoration is not achieved in all cases. Advances in using stem cell (SC) therapy hold a great promise for treating infertile patients due to their abilities to self-renew, differentiate, and produce different paracrine factors to regenerate the damaged or injured cells and replenish the affected germ cells. Furthermore, SCs secrete extracellular vesicles (EVs) containing biologically active molecules including nucleic acids, lipids, and proteins. EVs are involved in various physiological and pathological processes and show promising non-cellular therapeutic uses to combat infertility. Several studies have indicated that SCs and/or their derived EVs transplantation plays a crucial role in the regeneration of different segments of the reproductive system, oocyte production, and initiation of sperm production. However, available evidence triggers the need to testify the efficacy of SC transplantation or EVs injection in resolving the infertility issues of the human population. In this review, we highlight the recent literature covering the issues of infertility in females and males, with a special focus on the possible treatments by stem cells or their derived EVs.

Fertility Preservation in Women: Indications and Options for Therapy

Fertility preservation (FP) is a vital issue for individuals in either reproductive or prepubescent stage of life when future fertility may be compromised. The objective of any FP intervention is to minimize or eliminate primary disease burden and to ensure maintaining or preserving reproductive health. Fertility potential can be affected by cancer therapy and numerous other factors, including advancing age, metabolic conditions, autoimmune diseases, specific surgical interventions, and sex affirmation procedures. A paradigm shift focusing on quality-of-life issues and long-term survivorship has emerged, especially because of advances in cancer diagnostics and treatment. Several FP techniques have been widely distributed, while others are still in the research stage. In addition, specific procedures and some potentially fertoprotective agents are being developed, aiming to minimize the hazards of gonadal damage caused by cancer therapy and decrease the need for more costly, invasive, and time-consuming FP methods. This review highlights the advances, indications, and options for FP, both experimental and well-established, in females of various age groups. An electronic search in PubMed, Embase, and Google Scholar databases was conducted, including retrospective studies, prospective clinical trials, meta-analyses, original reviews, and online abstracts published up to June 30, 2019. The search terms used included fertility preservation, oncofertility, embryo cryopreservation, oocyte cryopreservation, and ovarian tissue cryopreservation. The meeting proceedings of the American Society for Reproductive Medicine and the European Society of Human Reproduction and Embryology were also hand searched.

Role of stem cells in fertility preservation: current insights

While improvements made in the field of cancer therapy allow high survival rates, gonadotoxicity of chemo- and radiotherapy can lead to infertility in male and female pre- and postpubertal patients. Clinical options to preserve fertility before starting gonadotoxic therapies by cryopreserving sperm or oocytes for future use with assisted reproductive technology (ART) are now applied worldwide. Cryopreservation of pre- and postpubertal ovarian tissue containing primordial follicles, though still considered experimental, has already led to the birth of healthy babies after autotransplantation and is performed in an increasing number of centers. For prepubertal boys who do not produce gametes ready for fertilization, cryopreservation of immature testicular tissue (ITT) containing spermatogonial stem cells may be proposed as an experimental strategy with the aim of restoring fertility. Based on achievements in nonhuman primates, autotransplantation of ITT or testicular cell suspensions appears promising to restore fertility of young cancer survivors. So far, whether in two- or three-dimensional culture systems, in vitro maturation of immature male and female gonadal cells or tissue has not demonstrated a capacity to produce safe gametes for ART. Recently, primordial germ cells have been generated from embryonic and induced pluripotent stem cells, but further investigations regarding efficiency and safety are needed. Transplantation of mesenchymal stem cells to improve the vascularization of gonadal tissue grafts, increase the colonization of transplanted cells, and restore the damaged somatic compartment could overcome the current limitations encountered with transplantation.

Social egg freezing under public health perspective: Just a medical reality or a women's right? An ethical case analysis

In recent years, a social trend toward delaying childbearing has been observed in women of reproductive age. A novel technomedical innovation was commercialized for non-medical reasons to healthy, ostensibly fertile women, who wished to postpone motherhood for various reasons such as educational or career demands, or because they had not yet found a partner. As a consequence, these women may be affected by age-related infertility when they decide to conceive, and fertility preservation techniques can be obtained through the so-called social egg freezing. This paper examines, from an ethical point of view, the impact of social egg freezing under some aspects that can involve policy making and resources allocation in public health. Due to the increasing demand for this procedure, some debated issues regard if it is reasonable to include social egg freezing in Public Healthcare System and consequently how to manage the storage of cryopreserved oocytes also from individual donors, how to support these egg banks and how to face, in the future, with the possibility that egg freezing will play a role in enabling childbearing for gays, lesbians, and unmarried persons. Social freezing may be advertised to harmonise gender differences, but we wonder if it is the proper solution to the problem or if it could also create further challenges. An ethical argumentation on these topics should address some questions that will be discussed.

Oocyte in vitro maturation: A sytematic review

In vitro maturation (IVM) is one of the most controversial aspects of assisted reproductive technology. Although it has been studied extensively, it is still not a conventional treatment option and is accepted as an alternative treatment. However, studies have shown that IVM can be used in almost all areas where in vitro fertilization (IVF) is used and it has a strong place in fertility protection and Ovarian Hyperstimulation syndrome management. The aim of this systematic review was to address all aspects of the current knowledge of IVM treatment together with the evolution of IVM and IVF.

In vitro maturation of human immature oocytes for fertility preservation and research material

Aim

In recent years, the importance of fertility preservation (FP) has increased. In vitro maturation (IVM), an important technique in FP, has started to be used in the clinic, but controversies persist regarding this technique. Here, a survey of IVM for FP is provided.

Methods

Based on a literature review, the applications of FP, methods of FP, IVM of oocytes that had been collected in vivo and ex vivo, maturation of oocytes after IVM for FP, cryopreservation of oocytes for FP, explanation of the procedures to patients, and recent research on FP using IVM were investigated.

Results

Although IVM for FP remains controversial, the application of FP is expected to expand. Depending on the age and disease status of the patient, various methods of oocyte collection and ovarian stimulation, as well as various needle types and aspiration pressures, have been reported. The maturation rate of IVM in FP ranges widely and requires optimization in the future. In regard to cryopreservation for matured oocytes, the vitrification method is currently recommended.

Conclusion

Regarding FP for patients with cancer, the treatment of cancer is prioritized; thus, the time and use of medicines are often constrained. As several key points regarding IVM remain unclear, well‐designed and specific counseling for patients is necessary.

Effects of trehalose vitrification and artificial oocyte activation on the development competence of human immature oocytes

Sucrose and trehalose are conventional cryoprotectant additives for oocytes and embryos. Ethanol can artificially enhance activation of inseminated mature oocytes. This study aims to investigate whether artificial oocyte activation (AOA) with ethanol can promote the development competence of in vitro matured oocytes. A total of 810 human immature oocytes, obtained from 325 patients undergoing normal stimulated oocyte retrieval cycles, were in vitro maturated (IVM) either immediately after collection (Fresh group n = 291)) or after being vitrified as immature oocytes (Vitrified group n = 519). These groups were arbitrarily assigned. All fresh and vitrified oocytes which matured after a period of IVM then underwent intra-cytoplasmic sperm injection (ICSI). Half an hour following ICSI, they were either activated by 7% ethanol (AOA group) or left untreated (Non-AOA group). Fertilization, cleavage rate, blastocyst quality and aneuploidy rate were then evaluated. High-quality blastocysts were only obtained in both the fresh and vitrified groups which had undergone AOA after ICSI. Trehalose vitrification slightly, but not significantly, increased the formation rates of high-quality embryos (21.7% VS 15.4%, P > 0.05) and blastocysts (15.7% VS 7.69%, P > 0.05)) when compared with sucrose vitrification. Aneuploidy was observed in 12 of 24 (50%) of the AOA derived high quality blastocysts. High-quality blastocysts only developed from fresh or vitrified immature oocytes if the ICSI was followed by AOA. This information may be important for human immature oocytes commonly retrieved in normal stimulation cycles and may be particularly important for certain patient groups, such as cancer patients. AOA with an appropriate concentration of ethanol can enhance the developmental competence of embryos.

FTY720 and cyclosporin protect ovarian tissue grafted into rabbits

OBJECTIVE

To determine whether FTY720 combined with CsA has immunomodulatory effects on human ovarian tissue transplanted to the back muscle of rabbits for an 8-week period.

STUDY DESIGN

We selected rabbits as recipients of ovarian xenografts with and without treatment by CsA and FTY720. Ovarian fragments from twelve patients were cut into 2 mm × 2 mm, 1-2mm thick pieces and randomly distributed into four groups: Group 1 (FTY720 2 mg/kg/d+CsA 3 mg/kg/d), Group 2 (FTY720 1 mg/kg/d+CsA 3mg/kg/d), Group 3 (FTY720 0.5 mg/kg/d+CsA 3mg/kg/d) and Group 4 for control (CsA 3 mg/kg/d). FTY720 was started three days before transplantation and was given daily after transplantation. CsA was administrated post-transplantation. All the animals were killed 8 weeks post- transplantation. Levels of serum estrogen (E2), interferon-γ (IFN-γ) and interleukin-4 (IL-4) were detected by radioimmunoassay and ELISA. Anti-CD31 and anti-Ki-67 antibodies were used to evaluate neo-vascularization in xenografts and proliferation activity of ovarian follicles. Peripheral CD4+/CD8+ T cells were analyzed by flow cytometry.

RESULTS

Combined treatment with cyclosporin A and FTY720 improved graft survival and reduced peripheral CD4+ and CD8+ T cell counts compared to treatment with cyclosporin A alone. Neovascularization took place in the peripheral zone of the xenograft while granulosa cells, positively stained by Ki-67, were found in early-stage follicles and stromal cells in the combined treatment groups.

CONCLUSION

FTY720 in combination with cyclosporin A maintains human ovarian xenografts in these rabbit models.

Current approach to fertility preservation by embryo cryopreservation

The ovaries are susceptible to damage following treatment with gonadotoxic chemotherapy, pelvic radiotherapy, and/or ovarian surgery. Gonadotoxic treatments have also been used in patients with various nonmalignant systemic diseases. Any women of reproductive age with a sufficiently high risk of developing future ovarian failure due to those medical interventions may benefit from embryo cryopreservation though the tools of assessment of such a risk are still not very precise. Furthermore, the risk assessment can be influenced by many other factors such as the delay expected after chemotherapy and the number of children desired in the future. Embryo cryopreservation is an established and most successful method of fertility preservation when there is sufficient time available to perform ovarian stimulation. This publication will review the current state, approach, and indications of embryo cryopreservation for fertility preservation.

Developmental potential of human oocytes matured in vitro followed by vitrification and activation

Background

Oocyte in vitro maturation (IVM) and cryopreservation at the time of routine ovarian tissue freezing may be offered to cancer patients as an additional option for fertility preservation. This study aimed to investigate the developmental capacity of oocytes isolated from unstimulated ovaries.

Methods

Immature oocytes (n = 63) from seven consenting premenopausal patients were analysed. Oocytes were collected during routine laparoscopic examination with biopsy of an ovary (cystic adnexal mass, n = 3; cervical adenocarcinoma, n = 2) or oophorectomy (sex reassignment surgery, n = 2) without previous stimulation of the ovaries. The stage of the patient’s menstrual cycle was not considered. Oocytes in all visible antral follicles were aspirated from ovaries, cultured in IVM medium and vitrified at the MII stage before being kept in liquid nitrogen for at least one month. After warming, oocytes were subjected to parthenogenetic activation by chemical stimulus. Their further development was recorded at intervals of 24 hours for up to 6 days of culture.

Results

61.9% of oocytes matured in vitro within 48 hours. The survival rate after vitrification and warming was 61.5%. A total of 75% of surviving oocytes were able to respond to artificial activation, 44.4% of the parthenotes developed to early embryonic stage. However, only 1 in 18 (5.6%) of the resulting embryos reached blastocyst stage.

Conclusions

Oocytes matured in vitro from unstimulated ovaries seem to have limited developmental potential after cryopreservation and artificial activation. Although the outcome of IVM for non-stimulated oocytes is poor, it is currently the only chance besides cryopreservation of ovarian tissue for women for whom ovarian stimulation is not possible due to life circumstances. Based on our preliminary results, we suggest that the use of cryopreserved ovaries for fertility preservation in women with cancer warrants further investigation.

Quality and functionality of human ovarian tissue after cryopreservation using an original slow freezing procedure

PURPOSE

To evaluate the efficiency of an original slow freezing protocol on the quality and function of human ovarian cortex.

METHODS

Human ovarian tissues were cryopreserved using a freezing medium supplemented with propanediol and raffinose as cryoprotectants and antioxidants (L-glutamine, taurine). Samples were then frozen using a faster cooling rate than the usual one. Viability and morphology of follicles, DNA fragmentation in follicles and stroma as well as histology of the vascular endothelium were analyzed before and after freezing/thawing. Moreover, a functional analysis was performed based on the evaluation of follicular growth and development in thawed ovarian tissues that were cultured in vitro.

RESULTS

Our freezing/thawing protocol allows preservation of a high proportion of viable follicles and the preservation of the different follicle developmental stages (p>0.05 versus fresh control). 70.5 ± 5.2 % of follicles retained an intact morphology after cryopreservation (p=0.04). Stroma cells but not follicles exhibited a slight increase of DNA fragmentation after thawing (p<0.05). Microvessel endothelium within thawed tissues appeared to be preserved. Granulosa cells showed signs of proliferation in follicles cultured for 12 days. Secretion of 17β-oestradiol significantly increased during in vitro culture.

CONCLUSIONS

This protocol leads to good preservation of ovarian integrity and functionality post-thawing and thus appears as a suitable technique of ovarian tissue cryopreservation in clinical settings. Further research could be extended to optimize conditions of in vitro culture.

Female fertility loss and preservation: threats and opportunities

BACKGROUND

Ovarian aging and cytotoxic treatments are the most common causes for fertility loss in women. With increasing numbers of young female survivors following cytotoxic cancer treatments, the issue of fertility preservation has assumed greater importance.

METHODS

We review the literature on the causes of female fertility loss as well as the recent advances in fertility preservation options and strategies that might be of interest to oncologists. Currently, several methods and techniques exist for fertility preservation of female patients with cancer including embryo freezing, ovarian protection techniques, oocyte cryopreservation, ovarian tissue cryopreservation followed by autotransplantation, and recently in vitro culture of ovarian tissue, follicles, and oocytes. Each method or technique has advantages and disadvantages related to current success rate, required delay in cancer treatment, sperm requirement, and risk of reintroducing cancer cells.

RESULTS

To date, embryo freezing is the only established method successfully and widely used for fertility preservation of female patients with cancer. The other methods are promising but still considered experimental.

CONCLUSION

Patient awareness, physician knowledge, early counseling, costs management, international registry, interdisciplinary networks, and research development are necessary to improve the current care in the field of female fertility preservation.

Concise review: fertility preservation: an update

Fertility preservation is an emerging field in medicine that enables men, women, and children to maintain reproductive health when it is threatened by gonadotoxic treatment. Patients affected by other nononcologic malignancies that can impair spermatogenesis and ovogenesis can also benefit from fertility preservation treatments. Age-related infertility can also be overcome by cryopreserving gametes or embryos. The only established methods for fertility preservation in male patients are sperm cryopreservation in postpubertal age and experimental testicular tissue cryopreservation in prepubertal age. In adult women, oocyte cryopreservation is the preferred option, whereas ovarian tissue cryopreservation is the only possibility for prepubertal girls. Fertility preservation treatments must be addressed through a multidisciplinary approach that involves gynecologists, urologists, oncologists, pediatricians, and professionals in the field of medically assisted reproduction to work in coordination to provide patients with counseling and comprehensive information about fertility issues.

Reproductive potential of a metaphase II oocyte retrieved after ovarian stimulation: an analysis of 23 354 ICSI cycles

BACKGROUND Live birth per cycle and live birth per embryo transfer are commonly used outcome measures for IVF treatment. In contrast, the assessment of the reproductive efficiency of human oocytes fertilized in vitro is seldom performed on an egg-to-egg basis. This approach may however gain importance owing to the increasingly widespread use of oocyte cryopreservation, as the technique is becoming more established. The aim of the current study is to quantify the reproductive efficiency of the oocyte according to ovarian ageing and ovarian response. METHODS We performed a retrospective analysis of the outcome of all consecutive patients attending for treatment between 1992 and 2009. The outcome in terms of live birth after fresh and cryopreserved embryo transfer per mature oocyte was calculated for 207 267 oocytes retrieved in 23 354 ovarian stimulation cycles. The oocyte utilization rate (number of live births per mature oocyte) was further analysed in relation to the ovarian response. RESULTS The oocyte utilization rate in women in the age of ≤ 37 years remains constant with a mean of 4.47% live birth per mature oocyte [95% confidence interval (CI): 4.32-4.61]. From the age of 38 years onwards, a significantly lower oocyte utilization rate was noted, declining from 3.80% at the age of 38 years to 0.78% at 43 years (P < 0.001). In this 38-43 years age group, oocyte utilization rate was no longer dependent on ovarian response (P = 0.87). CONCLUSIONS The major strength of the study, which is also its weakness, is the fact that we included a large number of cycles performed over a long period of time. According to our results, the oocyte utilization rate between 23 and 37 years of age depends largely on ovarian response and to a much lesser extent on age. From the age of 38 years onwards, the utilization rate depends largely on age and to a much lesser extent on ovarian response. Considering the increased use of oocyte freezing for fertility preservation, these data are extremely valuable as they provide an estimate of the number of oocytes needed to achieve a live birth.

Nanoliter droplet vitrification for oocyte cryopreservation

AIM

Oocyte cryopreservation remains largely experimental, with live birth rates of only 2-4% per thawed oocyte. In this study, we present a nanoliter droplet technology for oocyte vitrification.

MATERIALS & METHODS

An ejector-based droplet vitrification system was designed to continuously cryopreserve oocytes in nanoliter droplets. Oocyte survival rates, morphologies and parthenogenetic development after each vitrification step were assessed in comparison with fresh oocytes.

RESULTS

Oocytes were retrieved after cryoprotectant agent loading/unloading, and nanoliter droplet encapsulation showed comparable survival rates to fresh oocytes after 24 h in culture. Also, oocytes recovered after vitrification/thawing showed similar morphologies to those of fresh oocytes. Additionally, the rate of oocyte parthenogenetic activation after nanoliter droplet encapsulation was comparable with that observed for fresh oocytes. This nanoliter droplet technology enables the vitrification of oocytes at higher cooling and warming rates using lower cryoprotectant agent levels (i.e., 1.4 M ethylene glycol, 1.1 M dimethyl sulfoxide and 1 M sucrose), thus making it a potential technology to improve oocyte cryopreservation outcomes.

Cryopreservation of human failed-matured oocytes followed by in vitro maturation: vitrification is superior to the slow freezing method

BACKGROUND

Oocyte cryopreservation is an important method used in a number of human fertility circumstances. Here, we compared the survival, in vitro maturation, fertilization, and early embryonic development rates of frozen-thawed human immature oocytes using two different cryopreservation methods.

METHODS

A total of 454 failed-matured oocytes [germinal vesicle (GV) and metaphase I (MI) stages] were collected from 135 patients (mean age 33.84 +/- 5.0 y) who underwent intracytoplasmic sperm injection (ICSI) cycles between February 2009 and December 2009 and randomly divided into a slow freezing group [1.5 mol/L-1, 2-propanediol (PROH) + 0.2 mol/l sucrose] and vitrification group [20% PROH + 20% ethylene glycol (EG) + 0.5 mol/l sucrose].

RESULTS

The vitrification protocol yielded a better survival rate than the slow freezing protocol at each maturation stage assessed. Regardless of the maturation stage (GV + MI), the slow freezing protocol had a significantly lower survival rate than the vitrification protocol (p < 0.001). In addition, a significant difference was found in the survival rates between GV and MI oocytes regardless of the protocol used (90.1 vs. 64.7%, respectively; p < 0.01). We also found that the maturation rates of GV and MI oocytes from the slow freezing and vitrification groups were 16.7 vs. 24.4% and 50.8 vs. 55.4%, respectively. Regardless of the protocol used, the GV oocytes had significantly lower viability than MI oocytes after 36 h of in vitro maturation (21.2 vs. 54.0%, respectively; p < 0.01). In addition, the GV and MI oocytes from the slow freezing group had a markedly lower maturation rate than those from the vitrification group (33.6 vs. 43.1%, respectively), but no statistical difference was found between the two groups (P > 0.05). For the GV-matured oocytes, no fertilized eggs were obtained in the slow-freezing group, while a 19.0% (4/21) fertilization rate was observed in the vitrification group. For the MI-matured oocytes, fertilization rates for the slow freezing and vitrified groups were 36% and 61.1%, respectively, but no significant difference was found between the two groups (PIn the Methods section in the MS, all procedures were compliant with ethical guidelines, i.e. approved by the Ethical Committee of our university and Informed Consent signed by each patient. > 0.05). In the GV vitrification group, no embryo formed; however, in the MI slow freezing group, 12 oocytes were fertilized, but only two achieved cleavage and were subsequently blocked at the 2-cell stage. In the MI vitrification group, a total of 22 embryos were obtained, five of which developed to the blastocyst stage.

CONCLUSIONS

Vitrification is superior to the slow freezing method in terms of the survival and developmental rates for the cryopreservation of human failed-matured oocytes. In addition, GV oocytes appeared to be more resistant than MI oocytes to the low temperature and cryoprotectant used during cryopreservation.

Artificial oocyte activation and human failed-matured oocyte vitrification followed by in vitro maturation

The investigation presented in this paper was conducted on the effect of oocytes activation on frozen–thawed human immature oocytes followed by in vitro maturation (IVM). A total of 386 failed-matured oocytes (germinal vesicle (GV) and metaphase I (MI) stages) was randomly divided into two groups: fresh group and vitrification group, GV group and MI group, respectively). The matured oocytes were subject to intracytoplasmic sperm injection (ICSI) after IVM had been carried out. The vitrification group was randomly divided into two groups: controlled and artificial oocyte activation (AOA). The injected oocytes in the controlled group were cultured in cleavage medium. The AOA group oocytes were activated by exposing them to 7% anhydrous alcohol for 6 min then cultured in cleavage medium as well. The rates of fertilization and early embryonic development were compared between the controlled and AOA groups. In MI vitrification group, the high-quality embryo formation rate and blastocyst formation rate were significantly higher in the AOA group than in the controlled group (P < 0.01). In the GV vitrification group, the high-quality embryo formation rate was significantly higher in the AOA group than in the controlled group (P < 0.05). These results indicate that AOA may be good for early embryonic development of vitrified immature human oocytes.

Nonmalignant diseases and treatments associated with primary ovarian failure: an expanded role for fertility preservation

Cancer treatments can be detrimental to fertility; recent literature has focused on the efforts of fertility preservation for this patient population. It should be recognized, however, that several nonmalignant medical conditions and therapeutic interventions could be similarly hazardous to fertility. Some of these nonmalignant diseases and their treatments that can adversely impact the reproductive axis are gastrointestinal diseases, rheumatologic disorders, nonmalignant hematologic conditions, neurologic disorders, renal disorders, gynecologic conditions, and metabolic diseases. Their negative effects on reproductive function are only now being appreciated and include impaired ovarian function, endocrine function, or sexual function and inability to carry a pregnancy to term. Complications and comorbidities associated with certain diseases may limit the success of established fertility preservation options. Recent advances in fertility preservation techniques may provide these patients with new options for childbearing. Here, we review several fertility-threatening conditions and treatments, describe current established and experimental fertility preservation options, and present three initiatives that may help minimize the adverse reproductive effects of these medical conditions and treatments by raising awareness of the issues and options: (1) increase awareness among practitioners about the reproductive consequences of specific diseases and treatments, (2) facilitate referral of patients to fertility-sparing or restorative programs, and (3) provide patient education about the risk of infertility at the time of diagnosis before initiation of treatment.

Cryopreservation of human failed maturation oocytes shows that vitrification gives superior outcomes to slow cooling

This study investigated whether failed maturation oocytes could be used to evaluate different cryopreservation procedures. A total of 289 failed maturation oocytes (GV and MI stages), obtained from 169 patients undergoing IVF treatment (mean age 33.84±5.0) were divided into two different slow-cooling groups (1.5 mol/l 1,2-propanediol+0.2 mol/l sucrose in either NaCl (group A) or choline chloride (ChCl) (group B) based cryopreservation solutions) and one vitrification group (15% ethylene glycol+15% dimethyl sulphoxide). Survival rate, in vitro maturation (IVM) rate, fertilization and developmental rate of cryopreserved oocytes were assessed. Regardless of the stage at which cryopreservation was performed (GV+MI), the slow cooling with ChCl based medium always gave significantly lower survival rate than the slow cooling in NaCl based medium (p=0.01) and vitrification (p<0.001). An extended study also showed statistically reduced survival rate between slow-cooling NaCl based medium and vitrification (p<0.05). Global results of in vitro maturation and fertilization showed worse results between both slow-cooling NaCl and ChCl based media versus vitrification. In conclusion, for oocytes that had failed to mature, vitrification gave better survival, maturation, fertilization and also cleavage rates than the slow-cooling protocols. Four cells embryos were obtained only from vitrified in vitro matured MI oocytes.

Fertility preservation: an option for women with cancer?

Many women of childbearing age are diagnosed with cancer in the United States each year. Improved survival rates can give many time to still have their own families if they choose. Although cancer treatments can dramatically increase survivorship, they also can negatively affect future fertility. Women newly diagnosed with cancer may not be aware of the possible damage to their future fertility as their main concern is survival. Women who may have their fertility compromised by cytotoxic treatments should be counseled and referred to reproductive specialists to explore their options. Although receiving a diagnosis of cancer is overwhelming, fertility counseling should be initiated as early as possible so that sufficient time exists to preserve fertility before ovarian damage occurs. Many fertility preservation options, including egg, embryo, and ovarian tissue freezing, can be done in a short period of time so as not to delay the start of cancer treatment. To educate and support women with cancer of childbearing age, oncology nurses should be aware of fertility preservation options and work closely with infertility nurses.

Offering excess oocyte aspiration and vitrification to patients undergoing stimulated artificial insemination cycles can reduce the multiple pregnancy risk and accumulate oocytes for later use

BACKGROUND

The prevention of multiple pregnancies remains a major challenge in patients treated with ovarian stimulation prior to intrauterine insemination (IUI). The pilot study presented here investigates whether multiple pregnancies can be minimized by a microscopically confirmed aspiration of oocytes from supernumerary follicles immediately before intrauterine insemination and evaluates the benefit of concomitant excess oocyte cryopreservation for future use.

METHODS

Thirty-four aspirations of supernumerary follicles were performed immediately prior to IUI in 31 patients undergoing ovarian stimulation. sIUI was only performed if cumulus-oocyte complexes were microscopically observed in the aspirated follicular fluid. All collected mature excess oocytes were cryopreserved using the vitrification technique.

RESULTS

Only four sIUI procedures had to be cancelled due to failed oocyte retrieval or premature ovulation. IUI treatment resulted in a clinical pregnancy rate of 23.5% per cycle. All were singleton pregnancies. A total of 111 oocytes were cryopreserved. Patients with polycystic ovary syndrome (PCOS) had an average of 6.07 oocytes vitrified, whereas patients without PCOS had 1.3 oocytes vitrified per cycle.

CONCLUSION

Microscopically confirmed collection of excess oocytes prior to stimulated IUI reduced cancellation rates, further reduced the risk for multiple pregnancy and may lead to future additional pregnancies because, based on current information, approximately 5% of the vitrified oocytes could potentially establish a pregnancy.

Orthotopic and heterotopic ovarian tissue transplantation

BACKGROUND

Transplantation of ovarian tissue is, at present, the only clinical option available to restore fertility using cryopreserved ovarian tissue. More than 30 transplantations of cryopreserved tissue have been reported, and six babies have been born, worldwide, following this procedure. Despite these encouraging results, it is essential to optimize the procedure by improving the follicular survival, confirming safety and developing alternatives. Here, we review the different factors affecting follicular survival and growth after grafting.

METHODS

Relevant studies were identified by searching Pubmed up to January 2009 with English language limitation. The following key words were used: (ovarian tissue or whole ovary) AND (transplantation) AND (cryopreservation or pregnancy). Using the literature and personal experience, we examined relevant data on the different exogenous and clinical factors affecting follicular development after grafting.

RESULTS

Clinical factors such as the patient's age and the transplantation sites influenced the lifespan of the graft. A heterotopic transplantation site is not optimal but offers some advantages and it may also promote the hormonal environment after a combined heterotopic and orthotopic transplantation. Exogenous factors such as antioxidants, growth factors or hormones were tested to improve follicular survival; however, their efficiency regarding further follicular development and fertility potential remains to be established.

CONCLUSION

Additional evidence is required to define optimal conditions for ovarian tissue transplantation. Alternatives such as whole ovary or isolated follicles transplantations require further investigation but are likely to be successful in humans in the future.

Vitrification of immature mouse oocyte using stepwise equilibration before or after in vitro maturation

Immature mouse oocytes before or after in vitro maturation (IVM) were vitrified by the use of either conventional one-step or three-step equilibration. Although vitrification after IVM using the stepwise method does not affect the cleavage rate, the early embryonic development was profoundly impaired in both protocols.

Sucrose affecting successful transplantation of vitrified-thawed mouse ovarian tissues

PURPOSE

The aim of this experiment is to detect effects of varying levels of sucrose on vitrified ovarian tissues.

METHODS

Ovarian tissues of mice were vitrified-thawed. Mice were randomly assigned to the fresh control group and experimental groups. According to different concentration of sucrose in vitrification solution, the experimental groups were randomly divided into Group I (0.2 M sucrose), Group II (0.4 M sucrose), Group III (0.8 M sucrose) and Group IV (1.6 M sucrose). Cytology was followed throughout the oophorectomy and transplantation period. Hormone levels and density of follicle were measured 1 month after transplantation.

RESULTS

The number of days before the resumption of estrous cycles in control group was significantly smaller than those in all of experimental groups. The serum estradiol levels of mice and the follicular density of ovarian grafts in control group were significantly higher than those in all of experimental groups. In addition, the number of days before the resumption of estrous cycles in Group II and Group III were smaller than those in Group I and Group IV. The serum estradiol levels of mice and the follicular density of ovarian grafts in Group II and Group III were significantly higher than those in Group I and Group IV. However, no difference was observed in the number of days before the resumption of estrous cycles and the serum estradiol levels between Group II and Group III. A similar follicular density was also observed in Group II and Group III.

CONCLUSION

Sucrose concentration of 0.4 M or 0.8 M in cryoprotective media is suitable for vitrifying mouse ovarian tissues.

Cryopreservation of a mother's oocytes for possible future use by her daughter with Turner syndrome: case report

OBJECTIVE

To report a new fertility alternative for women with Turner syndrome, who are rendered infertile, by having their mothers freeze their own oocytes for the purpose of donating to their daughters when they are adults.

DESIGN

Case report.

SETTING

Academic teaching hospital.

PATIENT(S)

A 33-year-old healthy mother of three children; and her second child, a 6-year-old daughter recently diagnosed with Turner syndrome.

INTERVENTION(S)

Mother-to-daughter oocyte donation combined with oocyte vitrification.

MAIN OUTCOME MEASURE(S)

Number of cryopreserved oocytes.

RESULT(S)

After three cycles of ovarian stimulation, 30 oocytes were cryopreserved for the daughter's possible future use.

CONCLUSION(S)

The treatment option presented here opens the door for the banking of a mother's oocytes as a possible donation to a young daughter with a medical condition that leads to infertility, for her possible future use.