Ovary and uterus transplantation

Preservation of fertility in female: Indications, available options, and current status in Saudi Arabia

Refinement of therapies continues to improve the prognosis and survival of cancer patients. However, women of reproductive age face a risk of premature ovarian failure due to the gonadotoxicity of aggressive oncological treatment, which may also be used to treat other nonmalignant disorders. Development of cryobiology and assisted reproduction has allowed fertility preservation, which is increasingly requested, and can also aid fertility in iatrogenic and noniatrogenic conditions. Established protocols including embryo and oocyte freezing are only performed for adult women; however, ovarian tissue cryopreservation is an approach that can also assist prepubertal girls. Medical fertility cryopreservation for females has been recently legalized in Saudi Arabia. However, prior to implementing the service in clinical practice in Saudi Arabia, guidelines on patient selection criteria and adequate staff training are essential. Moreover, worldwide registry data and the findings of long-term studies involving many patients on the safety of ovarian tissue freezing are required to conclusively establish medical fertility cryopreservation as a safe procedure. Progress can be achieved in oncofertility by improving and optimizing techniques that include immature oocyte growth and maturation and artificial ovary development.

Female fertility preservation: past, present and future

Anti-cancer therapy, particularly chemotherapy, damages ovarian follicles and promotes ovarian failure. The only pharmacological means for protecting the ovaries from chemotherapy-induced injury is gonadotrophin-releasing hormone agonist, but its efficiency remains controversial; ovarian transposition is used to shield the ovary from radiation when indicated. Until the late 1990s, the only option for fertility preservation and restoration in women with cancer was embryo cryopreservation. The development of other assisted reproductive technologies such as mature oocyte cryopreservation andin vitromaturation of oocytes has contributed to fertility preservation. Treatment regimens to obtain mature oocytes/embryos have been modified to overcome various limitations of conventional ovarian stimulation protocols. In the last decades, several centres have begun cryopreserving ovarian samples containing primordial follicles from young patients before anti-cancer therapy. The first live birth following implantation of cryopreserved-thawed ovarian tissue was reported in 2004; since then, the number has risen to more than 130. Nowadays, ovarian tissue cryopreservation can be combined within vitromaturation and vitrification of oocytes. The use of cryopreserved oocytes eliminates the risk posed by ovarian implantation of reseeding the cancer. Novel methods for enhancing follicular survival after implantation are presently being studied. In addition, researchers are currently investigating agents for ovarian protection. It is expected that the risk of reimplantation of malignant cells with ovarian grafts will be overcome with the putative development of an artificial ovary and an efficient follicle class- and species-dependentin vitrosystem for culturing primordial follicles.

In vivo and in vitro strategies to support caprine preantral follicle development after ovarian tissue vitrification

The aim of the present study was to compare fresh and vitrified goat ovarian tissue after autotransplantation and in vitro culture. Adult goats were completely ovariectomised and each ovarian pair was sliced and distributed among six different treatment groups: fresh control, fresh transplant, fresh culture, vitrified control, vitrified transplant and vitrified culture. Follicular morphology, development, growth, density, revascularisation and hormone production were evaluated in all groups. Three antral follicles (two in the fresh transplant and one in the vitrified transplant groups) were observed on the surface of the graft 90 days after transplantation. The percentage of morphologically normal follicles was similar in the fresh control, fresh transplant and vitrified transplant groups. The percentage of developing (transition, primary and secondary) follicles was higher after in vitro culture of fresh or vitrified tissue. Transplantation resulted in a lower follicle density. Serum oestradiol concentrations remained constant during the entire transplantation period. In contrast, progesterone production decreased significantly. Expression of CD31 mRNA was lower in fresh culture. In conclusion, restoration of goat ovarian function can be successfully achieved following transplantation of both fresh and vitrified goat ovarian tissue. However, transplantation induced higher follicle loss than in vitro culture.

The Effects and Possible Mechanisms of Puerarin to Treat Uterine Fibrosis Induced by Ischemia-Reperfusion Injury in Rats

Background

Tissues fibrosis is caused by ischemia-reperfusion injury (IRI) and results in organ dysfunction. In this study, we aimed to investigate whether fibrosis occurs after uterine ischemia-reperfusion injury, and to investigate the effects of puerarin (Pur) on the fibrosis process in rats.

Material/Methods

Twenty-four female Wistar rats were randomly divided into three groups (8 in each group): the control group rats only received operation without uterine ischemic, the IRI group and the IRI + Pur group rats received 30-minutes ischemia and 2-weeks of reperfusion. Pur was orally administered at the onset of reperfusion. Picrosirius red staining was used to assess uterine fibrosis. Immunohistochemistry was used to detect the expression levels of transforming growth factor (TGF)-β and α-smooth muscle actin (α-SMA). Western blotting was used to evaluate the expression of chymase, TGF-β, α-SMA, and the activity of the Wnt/β-catenin pathway.

Results

Uterine fibrosis in the IRI+Pur group was significantly decreased compared with the IRI group. In addition, immunohistochemistry reveals that TGF-β and α-SMA were decreased in the IRI+Pur group compared with the IRI group. Western blotting results showed that Pur significantly suppresses the increase in chymase, α-SMA, TGF-β, and β-catenin expression levels induced by IRI.

Conclusions

The results indicated that IRI could induce uterine fibrosis and that Pur had an improvement effect on IRI-induced uterine fibrosis by downregulating the activity of mast cell chymase, TGF-β, α-SMA, and the Wnt/β-catenin pathway.

Extragonadal oocytes residing in the mouse ovarian hilum contribute to fertility

The observation of pups born from recipient and donor mice after ovariectomy followed by ovarian transplant poses the interesting possibility of an extraovarian source of oocytes. However, whether mammalian adult oocytes reside in extragonadal tissues remains elusive. Using transgenic fluorescent reporter mice and transplantation surgeries, we demonstrate the presence of both donor- and recipient-derived corpora lutea and recovery of both donor- and recipient-derived offspring from ovariectomized mice after transplantation of donor ovaries. A potential region for extraovarian oocytes is the hilum, a ligament-like structure between the ovary and the reproductive tract. Immunofluorescent confocal microscopy of mouse ovaries and reproductive tracts revealed that a population of primordial follicles resides outside the ovary within the hilum. Ovariectomy-only controls confirmed that oocytes remain in the recipient hilum after surgery. These results provide evidence that the hilum is a reserve source of follicles, which likely return to the ovary for maturation and ovulation. By identifying a new follicle reservoir, our study addresses a long-standing question in reproductive biology and contributes to new conceptual knowledge about ovarian function and fertility.

Histomorphometric Evaluation of Superovulation Effect on Follicular Development after Autologous Ovarian Transplantation in Mice

The effect of superovulation by pregnant mare serum gonadotropin (PMSG) on autologous transplanted ovaries in the lumbar muscles of mice was histomorphometrically evaluated using the indices of number and volume of different kind of follicles and volume of corpora lutea, ovary, and stroma. Angiogenesis was observed after mouse ovarian transplantation on days 14 and 21 after ovarian grafting. After transplantation, the total number and volume of primary and secondary follicles reduced, while PMSG superovulation increased the total number and total volume of tertiary follicles and also the ovarian volume after transplantation. Transplantation increased the average size of primary, secondary, and tertiary follicles. Therefore, primary and secondary follicles can survive after autologous transplantation but their reservations diminished by increasing the time of transplantation. However, number of tertiary follicles and their response to superovulation increased over time after transplantation.

The effects of tacrolimus on the activity and expression of tissue factor in the rat ovary with ischemia-reperfusion induced injury

In the present study, the effects of tacrolimus on the activity and expression of tissue factor (TF) were investigated in the ovarian ischemia-reperfusion induced injury in rats. Twenty-eight female rats (8-12 weeks, 300-350 g) were divided into four groups: control, ischemia-reperfusion (IR), tacrolimus treated before ischemia (TBI), and tacrolimus treated before reperfusion (TBR) groups (n=7/per group). TF activity was measured using Quick's method, whereas TF expression was examined immunohistochemically. TF activity was significantly higher in all treated groups compared with the control group. Strong ovarian TF expression was demonstrated in the IR and TBR groups. Moreover, tacrolimus decreased TF activity in the TBI group compared with the IR group. The decreased activity of TF in the ovarian IR model may prevent IR-related inflammation during transplant procedure.

Recovery of fertility from adult ovarian tissue transplanted into week-old Japanese quail chicks

Fertility of cryopreserved ovarian tissue from immature chickens and Japanese quail has been recovered by transplantation. This is of special importance for non-mammalian vertebrates in which cryopreservation and in vitro maturation of oocytes are challenging because their oogenesis is characterised by vitellogenesis. This study tested whether fertility of adult quail ovarian tissue could be recovered by transplantation. Ovaries were isolated from mature Japanese quail hens, trimmed, cut into 3- to 4-mm2 pieces and transplanted into ovariectomised, week-old chicks. Recipients were administered an immunosuppressant for two weeks. Ten of 12 recipients survived until sexual maturity and seven laid eggs, but all stopped laying by 17 weeks of age. The age at first egg of recipients laying eggs (75.7 ± 4.2 days) was greater than that of untreated hens (51.8 ± 1.7 days) and egg production of recipients during the laying period (21.7 ± 5.7) was less than that of untreated hens (60.8 ± 3.5). Recipients were paired with males from the WB line for test mating. Only two hens laid eggs during the test period but both produced 100% donor-derived offspring. This research demonstrated that the reproductive potential of ovarian tissue from adult quail hens can be restored by transplantation.

ESHRE Task Force on Ethics and Law 23: medically assisted reproduction in singles, lesbian and gay couples, and transsexual people†

This Task Force document discusses ethical issues arising with requests for medically assisted reproduction from people in what may be called 'non-standard' situations and relationships. The document stresses that categorically denying access to any of these groups cannot be reconciled with a human rights perspective. If there are concerns about the implications of assisted reproduction on the wellbeing of any of the persons involved, including the future child, a surrogate mother or the applicants themselves, these concerns have to be considered in the light of the available scientific evidence. When doing so it is important to avoid the use of double standards. More research is needed into the psychosocial implications of raising children in non-standard situations, especially with regard to single women, male homosexual couples and transsexual people.

Effect of therapeutic ultrasound on folliculogenesis, angiogenesis and apoptosis after heterotopic mouse ovarian transplantation

One of the challenges in ovarian transplantation is ischemia-reperfusion damage. When transitional tissue faces an acute and critical condition in terms of blood supply (immediately after organ transplantation), treatment with low-intensity pulsed ultrasound (LIPUS) seems to be very beneficial. The aim of this study was to evaluate the effects of ultrasound therapy on heterotopic transplanted mouse ovarian tissue. Adult female Naval Medical Research Institute mice were divided into three groups. In the experimental groups, the transplanted ovary was exposed 5 min daily to ultrasound with an intensity of 0.3 W/cm(2), frequency of 3 MHz and pulse mode of 1:4. The grafted ovaries were assessed with the usual histology and immunohistochemistry techniques. Results indicate that more CD31 angiogenic factor was expressed in irradiated animals than in control animals, and ultrasound therapy resulted in better follicular preservation, especially after 14 d. In conclusion, therapeutic ultrasound may accelerate and increase re-angiogenesis and can help to promote ovarian follicular growth.

Bioengineering the ovarian follicle microenvironment

Chemo- and radiation therapies used to treat cancer can have the unintended effect of making patients infertile. Clinically established fertility preservation methods, such as egg and embryo cryopreservation, are not applicable to all patients, which has motivated the development of strategies that involve ovarian tissue removal and cryopreservation before the first sterilizing treatment. To restore fertility at a later date, the early-stage follicles present in the tissue must be matured to produce functional oocytes, a process that is not possible using existing cell culture technologies. This review describes the application of tissue engineering principles to promote ovarian follicle maturation and produce mature oocytes through either in vitro culture or transplantation. The design principles for these engineered systems are presented, along with identification of emerging opportunities in reproductive biology.

Direct comparative analysis of conventional and directional freezing for the cryopreservation of whole ovaries

OBJECTIVE

To compare conventional slow equilibrium cooling and directional freezing for cryopreservation of whole ovaries.

DESIGN

Experimental animal study.

SETTING

Academic research environment.

ANIMAL(S)

Adult ewes.

INTERVENTION(S)

Eighty-one ovaries were randomly assigned to fresh control, conventional freezing (CF), and directional freezing (DF) group. Ovaries of CF and DF groups were perfused via the ovarian artery with Leibovitz L-15 medium, 10% fetal bovine serum, and 1.5 M dimethyl sulfoxide for 5 minutes. Each ovary was inserted into a glass test tube containing 10 mL of the same solution and cooled to -100°C or -70°C, respectively. Ovaries were stored in liquid nitrogen for a minimum of 2 weeks.

MAIN OUTCOME MEASURE(S)

Structural integrity of cortical and medulla regions, vascular integrity, follicle in vitro development, cell proliferation, and DNA damage and repair.

RESULT(S)

All examined parameters indicate that the structure of DF ovaries remains largely intact and comparable to fresh controls, whereas significant damages were observed in CF ovaries.

CONCLUSION(S)

Directional freezing allows good preservation of whole ovaries, with most of the parameters taken into consideration almost identical to those recorded in fresh control samples. This encourages a reconsideration of the possible use of whole-ovary cryopreservation as a viable alternative to cortical fragments.

Memoir of fertility preservation

Fertility preservation has been practiced for at least 50 years using semen banking, pelvic surgery, and radiation shields, but in the past 20 years it has emerged as a rapidly growing subspecialty of reproductive medicine. A dramatic rise in survivorship of young cancer patients and the widespread postponement of family building to the later years of the female reproductive lifespan have been major driving forces. Throughout the history of fertility preservation, low temperature banking has played a pivotal role, first for gametes and later for embryos and immature germ cells, while ovarian transplantation recently began to contribute and spermatogonial stem cell transfer holds future promise for men and prepubertal boys. But there are significant risks with some diseases from reimplanting residual disease, which hopefully can be eliminated by new methods for purging the tissue and germ cell culture. Since all technologies are interim, cryopreservation as a mainstay in this field will likely be swept aside eventually by a stream of progress aimed at managing fertility preservation in vivo.

Ovarian tissue and follicle transplantation as an option for fertility preservation

OBJECTIVE

To review and summarize data from the scientific literature on ovarian tissue and follicle transplantation as an option for fertility preservation.

DESIGN

Review of pertinent literature.

SETTING

University hospital.

PATIENT(S)

Women having undergone ovarian tissue transplantation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Review of the literature.

RESULT(S)

Over the last decade, the field of ovarian transplantation and cryopreservation has significantly progressed, becoming applicable in humans. Indeed, fresh and frozen cortical ovarian tissue transplantations have been successfully reported worldwide, resulting in around 28 healthy babies. Although ovarian-tissue harvesting seems to be safe, the risk of reimplantation of cancer from ovarian cortical transplants cannot be estimated at this time. As a consequence, auto-transplantation of ovarian tissue in women having suffered from systemic hematological malignancies is not recommended. In these situations, reimplantation of isolated ovarian follicles might represent an interesting option in the future.

CONCLUSION(S)

Although the clinical experience is limited, the robust results obtained open new perspectives for the management of premature ovarian failure resulting or not from gonadotoxic treatments.

Fertility preservation in girls and young women

There is increasing interest and experience in the options available to preserve fertility in those about to undergo potentially gonadotoxic chemotherapy or radiation therapy, usually related to treatment for cancer. Recent years have seen the development of methods for prepubertal girls, female adolescents and adult women, although these remain less established than sperm cryopreservation for men. At present, the options for prepubertal boys remain experimental. Embryo cryopreservation following ovarian stimulation and IVF is a routine procedure technically and its success in the management of infertility is established. However, there are no data on uptake or success rates in the context of fertility preservation in women with cancer. Oocyte cryopreservation is technically challenging and requires ovarian stimulation, thus potentially resulting in a delay in cancer treatment. Oocyte vitrification offers increased success rates in comparison with slow freezing; however, this approach is also limited by the number of oocytes that can be obtained. The third possibility, ovarian tissue cryopreservation, can be performed without significant delay and is the only option for prepubertal girls. Worldwide, a small number of children have been born following reimplantation of frozen/thawed ovarian tissue. It is clear that fertility preservation is important for some girls and young women facing treatments that will compromise their fertility, but the availability of all approaches varies widely. Effective approaches for prepubertal boys are also required.

Follicle growth and oocyte development after ovary transplantation into back muscle of immune-intact adult castrated male mice

Ovary grafting is not only a method of investigating follicle and oocyte development, but also a useful model to explore the possibility of the re-establishment of the reproductive axis in male-to-female sexual reversal. This study investigated ovary survival and follicle development after mouse ovaries were transplanted into immune-intact castrated male mice. Ten-day-old mouse ovaries were transplanted into the back muscle of adult outbred castrated male mice treated with immunosuppressants. Twenty-two days later, the ovary structure and the number of follicles present was examined by hematoxylin and eosin staining. The oocytes were harvested, and then used for in vitro maturation (IVM) and IVF. The results showed that primordial and antral follicles were mainly found in the grafts, and there were obvious differences compared with 32-day-old fresh ovaries (P<0.05). Embryos were derived from collected oocytes after IVM and IVF with a 72.4% cleavage rate and 7.9% blastocyst rate; 12 live pups were generated by embryo transfer. The hormone assay showed that plasma concentrations of both estrogen and progesterone increased after ovarian transplantation (P<0.01). In conclusion, immune-intact adult castrated male mice can support ovary survival and further development of follicles with endocrine function after ovarian transplantation.

Robert T. Morris, M.D.--appreciation of an enlightened surgeon and pioneer of ovarian transplantation

OBJECTIVE

To show that ovarian transplantation is a promising strategy for preserving fertility in young women and children who have cryopreserved tissue before undergoing potentially sterilizing treatment for cancer and other conditions.

CONCLUSION

Credit for the first transplants is because of a forgotten pioneer, Robert Morris of New York, who was an innovative surgeon as well as a model clinical investigator over a century ago.

Gene expression profile of rat ovarian tissue following xenotransplantation into immune-deficient mice

Immune-compromised mice have been used as gonadal tissue recipients to develop gametes of various mammalian species. The aim of this research was to determine gene expression differences between fresh and frozen–thawed rat xenotransplanted (XT) ovaries as well the gene expression differences between XT and sexually mature rat ovaries that were non-transplanted (NT). Ovaries from sexually immature female rats were transplanted under the kidney capsule of ovariectomized athymic nude mice either fresh or after freezing. The XT ovaries were collected ∼10–12 weeks after xenografting for microarray analysis. The NT ovaries were collected from sexually mature rats. Gene expression was very similar between fresh and cryopreserved XT ovaries: 125 genes were twofold up- or downregulated, but level of regulation was not statistically significant. Overall patterns of gene expression between XT and NT ovaries were very different indicated by the absence of diagonal relationship between XT and NT ovary gene expression. More than 3000 genes were significantly (P<0.01) up- or downregulated between XT and NT ovaries. Genes involved in metabolic processes, lipid metabolism, and growth were downregulated in XT ovaries, whereas genes involved in immune and inflammatory response were upregulated in XT ovaries. The results showed that ovarian tissue xenografting significantly alters genes responsible for ovarian metabolism and function and leads to an upregulation of genes responsible for graft rejection.

Fertility preservation techniques: laboratory and clinical progress and current issues

Human fertility is dependent on maturation of germ cells through meiosis and their association with supporting cells, which in the female are also the source of sex steroids. These processes are sensitive to both chemotherapy and radiotherapy thus can be damaged by anti-cancer treatments. The uterus is also sensitive to radiotherapy. Our understanding of and the ability to manipulate fertility has increased together with survival rates from many cancers, particularly those affecting children, younger men, and women. The growth of interest in fertility preservation for cancer patients is a natural union of these two fields. Sperm banking has been available for many years, and is a recognized and evidence-based option for men that should be available to all. Options for women and pre-pubertal boys and girls are, however, more experimental, other than for women of committing oocytes to fertilization and cryopreservation as embryos. This Focus Issue of Reproduction aims to address the current status of some of the clinical and laboratory aspects of this burgeoning subspecialty to highlight not only areas of progress but also areas of uncertainty where future developments are required to allow the provision of accurate information, and safe and effective treatments.

The oocyte population is not renewed in transplanted or irradiated adult ovaries

BACKGROUND

According to conventional theory, the oocyte population is not renewed in mammalian ovaries after birth. A new hypothesis proposes that oocytes are generated continuously from haematopoietic progenitor cells. There is, however, no evidence that they can ovulate, although they may partially restore fertility by organizing 'helper follicles'. The hypothesis that follicles can form de novo in adult ovaries has been tested in a transplant model.

METHODS

Ovaries from adult mice were transplanted under the kidney capsule or into the ovarian bursa of histocompatible, transgenic CAG::H2B-EGFP host animals. Some donors were sterilized before transplantation by X-irradiation to ensure 'empty niches' were available for repopulation. The phenotype of follicular oocytes at 2, 4 and 8 weeks post-transplantation was scored by epifluorescence.

RESULTS

A total of 819 oocytes were examined in 30 ovarian grafts. None expressed green fluorescence, as would be predicted if they had formed de novo from germ cell progenitors in the systemic circulation of the host. Furthermore, small follicles eliminated by irradiation were not replaced in transplanted ovaries, and the few growing follicles present were apparently survivors of the original population.

CONCLUSIONS

No evidence was found to support the hypothesis that progenitor cells from extra-ovarian sources can repopulate the adult ovary. The findings are consistent with the conventional view that a limited number of oocytes are formed before birth and declines with age. The study did not, however, rule out the possibility that germline stem cells may reside in the adult ovary.