Pregnancy after allogeneic uterus transplantation in the rat: perinatal outcome and growth trajectory

A new bicornuate model of rat uterus transplantation

INTRODUCTION

Uterus transplantation has revolutionized reproductive medicine for women with absolute uterine factor infertility, resulting in more than 40 reported successful live births worldwide to date. Small animal models are pivotal to refine this surgical and immunological challenging procedure aiming to enhance safety for both the mother and the child.

MATERIAL AND METHODS

We established a syngeneic bicornuate uterus transplantation model in young female Lewis rats. All surgical procedures were conducted by an experienced and skilled microsurgeon who organized the learning process into multiple structured steps. Animals underwent meticulous preoperative preparation and postoperative care. Transplant success was monitored by sequential biopsies, monitoring graft viability and documenting histological changes long-term.

RESULTS

Bicornuate uterus transplantation were successfully established achieving an over 70% graft survival rate with the passage of time. The bicornuate model demonstrated safety and feasibility, yielding outcomes comparable to the unicornuate model in terms of ischemia times and complications. Longitudinal biopsies were well-tolerated, enabling comprehensive monitoring throughout the study.

CONCLUSIONS

Our novel bicornuate rat uterus transplantation model provides a distinctive opportunity for sequential biopsies at various intervals after transplantation and, therefore, comprehensive monitoring of graft health, viability, and identification of potential signs of rejection. Furthermore, this model allows for different interventions in each horn for comparative studies without interobserver differences contrary to the established unicornuate model. By closely replicating the clinical setting, this model stands as a valuable tool for ongoing research in the field of uterus transplantation, promoting further innovation and deeper insights into the intricacies of the uterus transplant procedure.

Uterus transplantation: from research, through human trials and into the future

Women suffering from absolute uterine factor infertility (AUFI) had no hope of childbearing until clinical feasibility of uterus transplantation (UTx) was documented in 2014 with the birth of a healthy baby. This landmark accomplishment followed extensive foundational work with a wide range of animal species including higher primates. In the present review, we provide a summary of the animal research and describe the results of cases and clinical trials on UTx. Surgical advances for graft removal from live donors and transplantation to recipients are improving, with a recent trend away from laparotomy to robotic approaches, although challenges persist regarding optimum immunosuppressive therapies and tests for graft rejection. Because UTx does not involve transplantation of the Fallopian tubes, IVF is required as part of the UTx process. We provide a unique focus on the intersection between these two processes, with consideration of when oocyte retrieval should be performed, whether, and for whom, preimplantation genetic testing for aneuploidy should be used, whether oocytes or embryos should be frozen and when the first embryo transfer should be performed post-UTx. We also address the utility of an international society UTx (ISUTx) registry for assessing overall UTx success rates, complications, and live births. The long-term health outcomes of all parties involved-the uterus donor (if live donor), the recipient, her partner and any children born from the transplanted graft-are also reviewed. Unlike traditional solid organ transplantation procedures, UTx is not lifesaving, but is life-giving, although as with traditional types of transplantation, costs, and ethical considerations are inevitable. We discuss the likelihood that costs will decrease as efficiency and efficacy improve, and that ethical complexities for and against acceptability of the procedure sharpen the distinctions between genetic, gestational, and social parenthood. As more programs wish to offer the procedure, we suggest a scheme for setting up a UTx program as well as future directions of this rapidly evolving field. In our 2010 review, we described the future of clinical UTx based on development of the procedure in animal models. This Grand Theme Review offers a closing loop to this previous review of more than a decade ago. The clinical feasibility of UTx has now been proved. Advancements include widening the criteria for acceptance of donors and recipients, improving surgery, shortening time to pregnancy, and improving post-UTx management. Together, these improvements catalyze the transition of UTx from experimental into mainstream clinical practice. The procedure will then represent a realistic and accessible alternative to gestational surrogacy for the treatment of AUFI and should become part of the armamentarium of reproductive specialists worldwide.

Involving Animal Models in Uterine Transplantation

Background

Absolute uterine factor infertility affects 0. 2% women of childbearing age around the world. Uterine transplantation (UTx) is a promising solution for many of them since the first birth from UTx was described by the Swedish team in 2014. The success of Utx in humans has become possible after a systematic and meticulous approach involving years of research on animal models. To date, more than 80 UTx procedures have been performed worldwide and 30 children were born.

Material and Method

This review summarizes the research preparation conducted in animals before beginning UTx in humans. It focuses on the advantages and limits of each animal model, their place in surgical training, and current contribution in research to improve UTx successes in humans. The different steps in the process of UTx have been analyzed, such as imaging, surgery, ischemia-reperfusion effects, rejection markers, immunosuppressive treatment, and pregnancy.

Conclusion

Animal models have played an essential role in the implementation of UTx, which is a highly complex procedure. While respecting the 3R requirements (replacement, refinement, and reduction), the surgical training using large animal models, such as notably ewes remain irreplaceable for teams wishing to initiate a UTx program. Furthermore, animal models are still mandatory in current research to improve the success rates of UTx in humans as well as to reduce the morbidity associated with this experimental infertility treatment.

Keio Uterus Transplantation Research: From Basic Research toward Future Clinical Application

Uterus transplantation (UTx) is now a potential option to allow women with uterine factor infertility to give birth. However, UTx is still at an experimental stage, and basic animal studies, including in non-human primates, are needed for the accumulation of data prior to clinical application. Considering that UTx may provide new hope to Japanese women, we launched UTx research in 2009 and have since accumulated a large archive of results in the UTx research field. Furthermore, we have carried out various activities aimed at the implementation of clinical applications of UTx in Japan while clarifying the ethical and social issues involved. Currently, the clinical application of UTx in Japan is just around the corner, and it is expected that UTx research will develop further in the future. Herein, we summarize our basic experiences using non-human primates and our activities with the goal of future clinical applications.

Uterus transplantation for fertility preservation in patients with gynecologic cancer

Cervical and endometrial cancer may impact women interested in future fertility in approximately 5-25% of cases. The recommended treatment for patients with early stage disease is hysterectomy and/or radiation leading to infertility. This is referred to as absolute uterine factor infertility. Such infertility was considered untreatable until 2014, when the first child was born after uterus transplantation. Thereafter, multiple births have been reported, mainly from women with Mayer-Rokitansky-Küster-Hauser syndrome, with congenital uterine absence, although also from a patient with iatrogenic uterine factor infertility caused by radical hysterectomy secondary to an early stage cervical cancer 7 years before uterus transplantation. A live birth after uterus transplantation may be considered promising for many who may not otherwise have this option.Uterus transplantation is a complex process including careful patient selection in both recipients and donors, in vitro fertilization, and complex surgery in the organ procurement procedure including harvesting the vessel pedicles with the thin-walled veins. Thereafter, the transplantation surgery with anastomosis to ensure optimal blood inflow and outflow of the transplanted organ. Knowledge regarding immunosuppression and pregnancy is essential. Lastly there is the hysterectomy component as the uterus must be removed. Multidisciplinary teams working closely are essential to achieve successful uterus transplantation and, ultimately, delivery of a healthy child. Both the living and deceased donor concept may be considered and we address both the advantages and disadvantages. This review summarizes the animal research thus far published on uterus transplantation, the suggested recipient selections including former gynecologic cancer patients, the living and deceased donor uterus transplantation concepts with reported results, and updated fertility outcomes.

Morphologic assessment of hypertonic citrate adenine, histidine-tryptophan-ketoglutarate, and university of Wisconsin solutions for hypothermic uterus preservation in rats

AIM

Optimizing perfusate for static cold storage is one of the key ways of reducing organ dysfunction and rejection in organ transplantation. Here, we tested the effectiveness of the three different solutions for hypothermic uterus preservation.

METHODS

Twenty rats were divided into four groups, five in each group. Uterine grafts were retrieved and perfused in situ. The uteri were preserved at 4°C in normal saline as control group (group NS), hypertonic citrate adenine (group HCA), histidine-tryptophan-ketoglutarate (group HTK), or university of Wisconsin solutions (group UW) for 0, 12, 24, and 48 h, respectively. HE, electron microscopy, TUNEL staining, and Cleaved Caspase3 immunohistochemical staining were assessed at each time point.

RESULTS

There was no significant difference in the uterine retrieval time, perfusion time, and the amount of perfusion solution in NS, HCA, HTK, and UW groups (p > 0.05). HCA and HTK can well preserve the pathological morphology of rat uterine tissues for up to 24 h, and the apoptosis rates of the two groups are 7.2% and 7.1%, respectively, with no statistical difference (p > 0.05). Still, the protective effect of HTK on the ultrastructure of cells was much better than HCA. There was a significant difference in the apoptosis rate of UW (6.5%), HTK (8.8%), and HCA (9.4%) at 48 h, with mitochondrial and endoplasmic reticulum structure well preserved only in UW.

CONCLUSION

At 4°C, normal saline is not suitable to preserve rat uterus for more than 12 h. The morphologic results would favor the use of HTK rather than HCA for short-term hypothermic uterus preservation (≤24 h). UW is better than HTK and HCA for 48 h hypothermic uterus preservation.

Allogeneic uterus transplantation in a rhesus model: A short-term graft viability study

Objective

This study examined the feasibility and safety of allogeneic uterus transplantation (UTx) from a living donor and assessed short-term graft viability in a rhesus model. This research is an important step towards further clinical application of UTx in humans.

Materials and methods

Four female rhesus monkeys with regular menstrual cycles were used in this study, the animals were either donors or recipients depending on ABO blood type compatibility. Retrieval surgery was performed to connect the uterus and uterine arteries together with the ovarian uterine vein from the living donor, and the vagina of the recipient was excised. After the back table had been prepared, bilateral uterine arteries were anastomosed end-to-side with the iliac externa arteries, and bilateral ovarian uterine veins were anastomosed end-to-side with the iliac externa vena. The transplanted uterus was evaluated based on the conditions of arterial blood, and flow was evaluated by transabdominal ultrasonography one month post operation. The conditions of the transplanted uterus were examined by secondary laparotomy. The reproductive function of rhesus monkeys was evaluated on the basis of the menstrual cycle.

Results

All 4 rhesus monkeys received the transplantation surgery without any surgical complications. No injury occurred in the other organs, and no vascular injury was observed in the allogeneic uterus. All recipients survived after the surgery with a 100% short-term survival rate. All recipients resumed normal menstruation within two months after surgery.

Conclusions

Our short follow-up shows that allogeneic UTx surgery is a safe and feasible technology in the rhesus model. The arterial conditions and blood flow of the grafted uterus can be monitored by ultrasonography examination.

First Successful Delivery after Uterus Transplantation in MHC-Defined Cynomolgus Macaques

Delivery following uterus transplantation (UTx)—an approach for treating uterine factor infertility—has not been reported in nonhuman primate models. Here, six female major histocompatibility complex (MHC)-defined cynomolgus macaques that underwent allogeneic UTx were evaluated. Antithymocyte globulin and rituximab were administered to induce immunosuppression and a triple maintenance regimen was used. Menstruation resumed in all animals with long-term survival, except one, which was euthanized due to infusion associated adverse reaction to antithymocyte globulin. Donor-specific antibodies (DSA) were detected in cases 2, 4, and 5, while humoral rejection occurred in cases 4 and 5. Post-transplant lymphoproliferative disorder (PTLD) developed in cases 2 and 3. Pregnancy was attempted in cases 1, 2, and 3 but was achieved only in case 2, which had haploidentical donor and recipient MHCs. Pregnancy was achieved in case 2 after recovery from graft rejection coincident with DSA and PTLD. A cesarean section was performed at full-term. This is the first report of a successful livebirth following allogeneic UTx in nonhuman primates, although the delivery was achieved via UTx between a pair carrying haploidentical MHCs. Experimental data from nonhuman primates may provide important scientific knowledge needed to resolve unsolved clinical issues in UTx.

First live birth after uterus transplantation in the Middle East

Background

The first live birth after uterus transplantation took place in Sweden in 2014. It was the first ever cure for absolute uterine factor infertility. We report the surgery, assisted reproduction, and pregnancy behind the first live birth after uterus transplantation in the Middle East, North Africa, and Turkey (MENAT) region.

A 24-year old woman with congenital absence of the uterus underwent transplantation of the uterus donated by her 50-year-old multiparous mother. In vitro fertilization was performed to cryopreserve embryos. Both graft retrieval and transplantation were performed by laparotomy. Donor surgery included isolation of the uterus, together with major uterine arteries and veins on segments of the internal iliac vessels bilaterally, the round ligaments, and the sacrouterine ligaments, as well as with bladder peritoneum. Recipient surgery included preparation of the vaginal vault, end-to-side anastomosis to the external iliac arteries and veins on each side, and then fixation of the uterus.

Results

One in vitro fertilization cycle prior to transplantation resulted in 11 cryopreserved embryos. Surgical time of the donor was 608 min, and blood loss was 900 mL. Cold ischemia time was 85 min. Recipient surgical time was 363 min, and blood loss was 700 mL. Anastomosis time was 105 min. Hospital stay was 7 days for both patients. Ten months after the transplantation, one previously cryopreserved blastocyst was transferred which resulted in viable pregnancy, which proceeded normally (except for one episode of minor vaginal bleeding in the 1st trimester) until cesarean section at 35 + 1 weeks due to premature contractions and shortened cervix. A healthy girl (Apgar 9-10-10) weighing 2620 g was born in January 2020, and her development has been normal during the first 6 months.

Conclusions

This is the first report of a healthy live birth after uterus transplantation in the MENAT region. We hope that this will motivate further progress and additional clinical trials in this area in the Middle East Region, where the first uterus transplantation attempt ever, however unsuccessful, was performed already three decades ago.

Experimental techniques for the development of a uterus transplantation model in cynomolgus macaques

Uterus transplantation (UTx) is now a treatment for women with uterine factor infertility to have a child. However, UTx is still largely at the experimental stage, and many medical issues remain unsolved. Therefore, adequate studies in large animals including non-human primates are required for validation of these issues. UTx research, especially in non-human primates, can provide important information for its full establishment in humans due to the anatomical and physiological similarities between the two. We accumulated data from UTx studies using cynomolgus macaques since 2009 and established autologous and allogeneic UTx models which led to deliveries after performing the procedure. In this paper, we summarized key points to develop UTx models in cynomolgus macaques based on our experience. UTx models in non-human primates can surely contribute new and beneficial knowledge in this field and can be useful for the further development of UTx in humans.

Human uterine vasculature with respect to uterus transplantation: A comprehensive review

Due to the novelty of uterus transplantation, data on preferable inflow and outflow of the graft are limited. This paper reviews the technique, type of vessels and the outcome. A systematic search of the PubMed database was conducted. We extracted and analyzed data on the arteries and veins utilized, types of anastomosis, types of donors, complications and the outcome. Thirty eight sources reported 51 human uterine transplantations, 10 graft thromboses and 25 live births. Inflow was established with two uterine arteries (UA) with/without the anterior division of the internal iliac artery in 62% (n = 31) of cases, two UA arteries with a segment/patch of the internal iliac artery in 34% (n = 17) of cases or two UA with a conduit in 4% of cases (n = 2). Both cases with a conduit developed thrombosis (n = 2). Arterial thrombosis/ischemia developed in 8 of the 51 cases. In 50% of cases with arterial thrombosis, atherosclerosis was identified as a possible cause. Outflow was established by two internal iliac veins with patches/segments in 27.5% of cases (n = 14) followed by two utero-ovarian veins in 25.5% (n = 13). Venous thrombosis occurred in 3 of the 51 cases. Uterine arteries with/without anterior division of the internal iliac artery were the most frequent arteries used for inflow and produced the highest patency rate. The presence of atherosclerosis and complex arterial reconstruction was associated with a high rate of arterial thrombosis. None of the veins utilized in the procedures appeared to be superior. There are insufficient data to draw a definite conclusion.

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome: a comprehensive update

BACKGROUND

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, also referred to as Müllerian aplasia, is a congenital disorder characterized by aplasia of the uterus and upper part of the vagina in females with normal secondary sex characteristics and a normal female karyotype (46,XX).

MAIN BODY

The diagnosis is often made during adolescence following investigations for primary amenorrhea and has an estimated prevalence of 1 in 5000 live female births. MRKH syndrome is classified as type I (isolated uterovaginal aplasia) or type II (associated with extragenital manifestations). Extragenital anomalies typically include renal, skeletal, ear, or cardiac malformations. The etiology of MRKH syndrome still remains elusive, however increasing reports of familial clustering point towards genetic causes and the use of various genomic techniques has allowed the identification of promising recurrent genetic abnormalities in some patients. The psychosexual impact of having MRKH syndrome should not be underestimated and the clinical care foremost involves thorough counselling and support in careful dialogue with the patient. Vaginal agenesis therapy is available for mature patients following therapeutical counselling and education with non-invasive vaginal dilations recommended as first-line therapy or by surgery. MRKH syndrome involves absolute uterine factor infertility and until recently, the only option for the patients to achieve biological motherhood was through gestational surrogacy, which is prohibited in most countries. However, the successful clinical trial of uterus transplantation (UTx) by a Swedish team followed by the first live-birth in September, 2014 in Gothenburg, proofed the first available fertility treatment in MRKH syndrome and UTx is now being performed in other countries around the world allowing women with MRKH syndrome to carry their own child and achieve biological motherhood.

CONCLUSION

Several advances in research across multiple disciplines have been made in the recent years and this kaleidoscopic review provides a current status of various key aspects in MRKH syndrome and provides perspectives for future research and improved clinical care.

Live birth after cervical ectopic uterus transplantation in mice

An ideal animal model is a prerequisite for the basic research of uterus transplantation. This study aimed to develop a new cervical ectopic uterus transplantation mice model, which was established by vascular anastomosis of the right common iliac artery and vein of the donor with the right common carotid artery and external jugular vein of the recipient, respectively, using the cuff method. The survival status of the transplanted uterus was assessed by macroscopic observation and histological examination after surgery, and the function of the graft uterus was tested by verifying whether the pregnancy is possible. A total of 40 transplants were performed, of which only 1 failed due to donor hemorrhage. After 26 transplants, the total operation time reduced to 52.4 ± 3.8 minutes, of which the total ischemia time took 6.6 ± 1.1 minutes. Sixty days after transplantation, all the graft uteri had a good blood supply and spontaneous contraction. The histology showed no significant difference between the transplanted uterus and the native. Embryo transfer experiments have proven that the transplanted uterus has uterine function. In conclusion, this new model is an effective and simple mice model for the studies of the scientific issues related to uterus transplantation.

Uterus transplantation: transition from experimental to clinical procedure

Uterus transplantation is a novel treatment to treat uterine factor infertility. This type of infertility is due to absence of an anatomical or functional uterus. This review covers important research findings in the field, and this research formed the base for introduction of uterus transplantation as an experimental clinical procedure. The basic animal-research investigated central facets such as surgery, immunosuppression, ischemia-reperfusion injury, rejection, and fertility. The first clinical uterus transplantation trial was started in 2013 and this was a live donor trial. The first live birth was reported in 2014 and this has been followed by a number of births from the initial trial in Sweden and in several other parts of the world. The uterus transplantations procedures and the live births that have been scientifically reported will be discussed in this review. Lastly, some aspects for an efficient transition from an experimental phase into a clinical phase of uterus transplantation will be discussed.

Global results of human uterus transplantation and strategies for pre-transplantation screening of donors

Absolute uterine factor infertility, due to absence or non-function of the uterus, is one of the few major subgroups of infertility that has remained without any treatment. Uterus transplantation has now been proposed as treatment for this type of infertility. The first attempt of human uterus transplantation was in 2000. This was a live donor case, but due to suboptimal surgical solutions it resulted in a necrotic uterus being removed after 99 days. This first human case, although a failure, inspired several research groups around the globe to initiate animal-based studies to investigate uterus transplantation in relation to surgery, immunosuppression, rejection and pregnancy outcome. The research was carried out in several animal species and advanced the field substantially. In 2011, the second uterus transplantation attempt was performed, and this involved a deceased donor procedure. Although the case was surgically successful, with resumed menstruations, clinical pregnancy with live birth could not be achieved. The first clinical trial of uterus transplantation was initiated in Sweden in 2013 and involved nine live donor procedures. The world's first live birth was reported from that trial in September 2014 and this was followed by two more births within that trial in November 2014. Births after uterus transplantation has since been reported from Sweden and other centers in Europe, North America, Latin America, and Asia. Thirty human uterus transplantation procedures have been reported in the scientific literature so far but by our personal knowledge the double number of procedures have been performed. The published cases will be reviewed in detail, and we will also describe the pregnancies of the live births that have been published. A small number of graft failures have occurred. These may in part be linked to suboptimal selection of donors, specifically concerning the quality of the uterine arteries. Consequently, we will also address the issue of strategies for pre-surgical screening of donors.

Uterus Transplantation as a Therapy Method in Mayer-Rokitansky-Küster-Hauser Syndrome

The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is the most common cause of uterine aplasia (underdevelopment or absence) at a frequency estimated to be worldwide of 1/4500 births of new-born female infants.

This is a literature review aiming to determine the sufficiency of the uterine transplantation (UTx) method as a therapeutic protocol for the MRKH syndrome.

Online searches were carried out in PubMed, Embase, CINAHL and Google scholar databases, during January and February 2019. The search included a combination of the various terms (see key words) as well as a combination of these terms in Greek and English so as to identify and display articles that would be as close as possible to the subject of research.

The online search yielded 95 articles. Eighty-five of these were considered as eligible and possible sources from the title and abstract presented but later were excluded, whereas 10 of them were selected to be included in the literature review. The literature review results showed that two therapeutic methods that are now successfully applied are the Vecchietti method and the Davydov method, which is the latest and less invasive technique but with equally if not improved immediate results. However, this treatment is not adequate to satisfy or provide a solution for the reproduction requirements of this patient group. The UTx proved sufficient.

Although uterus transplant could be considered the ideal solution for the management of infertility and the satisfaction of the reproductive and sexual needs of women with MRKH syndrome, since the first successful pregnancy after uterine transplantation is a reality in the recent years, it is early days to be considered as a safe mode of management.

Long-Term Outcome and Rejection After Allogeneic Uterus Transplantation in Cynomolgus Macaques

Uterus transplantation (UTx) is an option for women with uterine factor infertility to have a child, but is still in the experimental stage. Therefore, allogeneic animal models of UTx are required for resolution of clinical issues. In this study, long-term outcomes were evaluated in four recipients (cases 1-4) after allogeneic UTx in cynomolgus macaques. Immunosuppression with antithymocyte globulin induction and a triple maintenance regimen was used. Postoperative ultrasonography and biopsy of the transplanted uterus and immunoserological examinations were performed. All four recipients survived for >3 months after surgery, but continuous menstruation did not resume, although temporary menstruation occurred (cases 1 and 2). All animals were euthanized due to irreversible rejection and no uterine blood flow (cases 1, 2 and 4) and post-transplant lymphoproliferative disorder (case 3). Donor-specific antibodies against MHC class I and II were detected in cases 1, 2 and 4, but not in case 3. Peripheral lymphocyte counts tended to elevate for CD3⁺, CD20⁺ and NK cells in conjunction with uterine rejection, and all animals had elevated stimulation indexes of mixed lymphocyte reaction after surgery. Establishment of allogeneic UTx in cynomolgus macaque requires further exploration of immunosuppression, but the clinicopathological features of uterine rejection are useful for development of human UTx.

The Key Role of Warm and Cold Ischemia in Uterus Transplantation: A Review

Introduction: Uterus transplantation (UTx) is a promising treatment for uterine infertility that has resulted in several births since 2014. Ischemia is a key step in organ transplantation because it may lead to changes jeopardizing graft viability. Method: We performed a systematic review of animal and human studies relating to uterine ischemia. Results: We retained 64 studies published since 2000. There were 35 studies in animals, 24 in humans, and five literature reviews. Modest preliminary results in large animals and humans are limited but encouraging. In small animals, pregnancies have been reported to occur after 24 h of cold ischemia (CI). In ewes, uterine contractions have been detected after 24 h of CI. Furthermore, it has been shown in animals that uterine tolerance to CI and to warm ischemia (WI) can be increased by pharmacological products. In women, mean CI time in studies of births from uteri obtained from live donors was between 2 h 47 min and 6 h 20 min from a deceased donor; with only one birth in this case. Muscle contractions have also been demonstrated in myometrial samples from women, after six or more hours of CI. Conclusion: The uterus seems to be able to tolerate a prolonged period of CI, of at least six hours. Studies of the ischemia tolerance of the uterus and ways to improve it are essential for the development of UTx, particularly for procedures using grafts from deceased donors.

Uterus Allo-Transplantation in a Swine Model: Long-Term Graft Survival and Reproductive Function

Background

The present study examined the feasibility and safety of allogeneic uterus transplantation (UTx) from a living donor and assessed long-term graft survival and the resumption of reproductive function in a swine model.

Material/Methods

Ten female miniature swine with regular menstrual cycles were used; the animals were either donors or recipients (n=5) depending on the sibling. Retrieval surgery included uterus and uterine arteries together with the anterior branches of the internal iliacs from the living donor; the vaginal canal was cut. After the back-table had been prepared, bilateral internal iliac arteries were anastomosed end-to-side with the external iliac arteries. The transplanted uterus was evaluated based on the arterial blood flow by transabdominal ultrasonography and observed by secondary laparotomy after surgery; estrus recovery was stimulated by mating with a male, and artificial embryo transfer was performed in healing swine.

Results

All 5 pigs revealed successful surgery without any surgical complications, injuries to other organs, or unanticipated vascular injury. All recipients survived for >3 months after the surgery, except pig 5, which died due to uterus necrosis 3 days post-surgery. A 100% surgical success rate and 80% long-term survival rate of the receptor were observed. Pig 2 had temporary estrus resumed, and the artificial embryo was transplanted 3 months after surgery; however, apparent gestation was not found by ultrasonography.

Conclusions

This study evaluated the safety and feasibility of the technology of allogeneic UTx, which was performed only by transplant uterine artery system from living-donor surgery in a swine model. Laboratory animals can show long-term survival and resumed estrous after UTx, which can be monitored by ultrasonography to assess the arterial blood flow of the grafted uterus.

Basic research on uterus transplantation in nonhuman primates in Japan

Uterus transplantation (UTx) is now a potential option for women with uterine factor infertility to have a child. However, UTx is still in an experimental stage and basic animal studies including in nonhuman primates are needed for accumulation of data that will provide important information for establishment of UTx in humans. Herein, we summarized our experiences using cynomolgus macaques, with the goal of promoting further development of UTx studies in nonhuman primates. Our basic studies using cynomolgus macaques were summarized, including the results of other teams in nonhuman primates. Our team in Japan launched UTx research in 2009 using cynomolgus macaques and has accumulated a large archive of results in the UTx research field, including examination of uterine blood flow, surgical procedures of autologous and allogeneic UTx, organ perfusion methods in deceased donor models, immunological response and rejection and ischemia/reperfusion injury. We achieved the first delivery after autologous UTx in primates and the first periodic recovery of menstruation after allogeneic UTx in nonhuman primate models. Results from animal studies, including those in nonhuman primates, provide the basis for clinical application of UTx. Therefore, our accumulated data since 2009 and our basic experience in cynomolgus macaque are meaningful for future UTx trials in Japan. In addition, more validation in nonhuman primate models is needed for resolution of medical issues and further development of UTx in humans, despite clinical application of UTx in several countries.

Selecting living donors for uterus transplantation: lessons learned from two transplantations resulting in menstrual functionality and another attempt, aborted after organ retrieval

PURPOSE

To contribute to establishing donor selection criteria based on our experience with two successful living-donor human uterus transplantations (UTx) and an aborted attempt.

METHODS

This interventional study included three patients with uterine agenesis, aged 23, 34, and 23 years, scheduled for UTx, and their uterus-donating mothers, aged 46, 61, and 46 years, respectively. Interventions included preoperative investigations, donor surgery, back-table preparation, and recipient surgery. Preoperative imaging, surgical data, histopathology, menstrual pattern, and uterine blood flow were the main outcome measures.

RESULTS

In the first case (46-year-old mother/23-year-old daughter), donor/recipient surgery took 12.12/5.95 h. Regular spontaneous menstruations started 6-week post-transplantation, continuing at 24-28-day intervals throughout the 6-month observation period. Repeated follow-up cervical biopsies showed no signs of rejection. In the second case (61-year-old donor), surgery lasted 13.10 h; attempts to flush the retrieved uterus failed due to extreme resistance of the left uterine artery (UA) and inability to perfuse the right UA. Transplantation was aborted to avoid graft vessel thrombosis or insufficient blood flow during potential pregnancy. Histopathology revealed intimal fibrosis and initial sclerosis (right UA), extensive intimal fibrosis (parametric arterial segments), and subtotal arterial stenosis (myometrial vascular network). In the third case (46-year-old mother/23-year-old daughter), donor/recipient surgery took 9.05/4.52 h. Menstruations started 6-week post-transplantation. Repeated cervical biopsies showed no signs of rejection during the initial 12-week follow-up period.

CONCLUSIONS

Meticulous preoperative evaluation of potential living uterus donors is essential. This may include selective contrast-enhanced UA angiograms and limitation of donor age, at least in donors with risk factors for atherosclerosis.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03048396.

Uterus transplantation: From animal models through the first heart beating pregnancy to the first human live birth

Absolute uterine factor infertility affects 3-5% of the general population, and unfortunately this condition is untreatable. There are some available options, including surrogacy or adoption, but neither of these suits each and every woman who desires to have her own genetic child. With recent advances in surgery and transplant immunology, uterus transplantation may be a source of hope for these women with uterine infertility. In the last decade, a number of animal species including rats, mice, rabbits, pigs, sheep, and primates have been used as experimental models, and pregnancies were achieved in some of these. Human data consist of 11 subjects yielding positive pregnancy results with no live births in the second trial from Turkey and, more fortunately, live births from the latest trial from Sweden. In the light of all these studies, uterus transplantation has been proven to be a viable option for women with uterine factor infertility.

Uterus transplantation: Toward clinical application in Japan

Background

In recent years, uterus transplantation (UTx) has been applied as the treatment for patients with uterine factor infertility worldwide. Thus, the clinical application of UTx in Japan should be considered through both the history of UTx technology development in the world and future prospects.

Methods

Recent information on UTx was collected via a literature survey and the Internet.

Results

Basic research using various animals has been done mainly since 2000. In 2014, the world's first UTx baby was born in Sweden. In total, 24 UTx procedures have been performed at 10 institutes in nine countries and five births were obtained (as of May, 2017). In Japan, the "Project Team for Uterus Transplantation" initiated UTx experiments in 2008 and the "Japan Society for Uterus Transplantation" was organized in March, 2014. In the rest of the world, the "International Society for Uterus Transplantation" was established in January, 2016.

Conclusion

Uterus transplantation is still under development as a reproductive medicine tool and organ transplant procedure. A collaborative system that is not limited by facilities and specialties should strive to build an "all-Japan" team.

Womb transplants with live births: an update and the future

INTRODUCTION

Absolute uterine factor infertility, with a uterine absence or presence of a nonfunctional uterus, has during the last decades been the only remaining, major group of female infertility. Uterus transplantation (UTx) has now emerged as the first therapy for these women that have traditionally been regarded as unconditionally infertile. Areas covered: This review summarizes the research preparations in several experimental animal species that paved the way for the clinical introduction of UTx. The article also describes the human UTx attempts that have been reported up until today and the several live births that have occurred after the initial UTx baby was born in 2014. Future developments in human UTx and efforts to create a bioengineered uterus are also discussed. Expert opinion: UTx has already at this early phase of experimental introduction in the human setting proved to be a highly effective treatment for absolute uterine factor infertility. The UTx procedure has now been introduced at several centers worldwide within clinical research studies and with variations in techniques. The outcome and data from these studies will further optimize the UTx procedure to become a safe and highly effective infertility treatment.

Monitoring of Human Uterus Transplantation With Cervical Biopsies: A Provisional Scoring System for Rejection

Until now, absolute uterine factor infertility has been the major untreatable form of female infertility. Uterus transplantation has recently proven to be the first successful treatment for absolute uterine factor infertility, with demonstration of live births. In this study, live donation uterus transplantation was performed in nine women. In total, 163 cervical biopsies (149 protocol, 14 follow-up) were taken to detect histopathological signs of rejection. Based on experience from animal experiments, we used a three-grade scoring system to evaluate biopsies systematically. Nine episodes of rejection were diagnosed in five patients: grade 1 in six episodes, grade 2 in two episodes, and grade 3 in one episode. Treatment decisions were based on histopathology, and all rejection episodes were reversed after treatment. The biopsies were reviewed retrospectively, and immunohistochemistry was performed to characterize the inflammatory infiltrates. A borderline category was introduced to avoid overtreatment of patients. Based on our review of all biopsies, we put forward a simple grading system for monitoring of rejection and to guide immunosuppressive treatment in uterus transplantation.

The history behind successful uterine transplantation in humans

This paper aimed to describe the basic aspects of uterine transplant (UTx) research in humans, including preliminary experiences in rodents and domestic species. Studies in rats, domestic species, and non-human primates validated and optimized the UTx procedure in terms of its surgical aspects, immunosuppression, rejection diagnosis, peculiarities of pregnancy in immunosuppressed patients, and patients with special uterine conditions. In animal species, the first live birth from UTx was achieved in a syngeneic mouse model in 2003. Twenty-five UTx procedures have been performed in humans. The first two cases were unsuccessful, but established the need for rigorous research to improve success rates. As a result of a controlled clinical study under a strictly designed research protocol, nine subsequent UTx procedures have resulted in six healthy live births, the first of them in 2014. Further failed UTx procedures have been performed in China, Czech Republic, Brazil, Germany, and the United States, most of which using living donors. Albeit still an experimental procedure in, UTx is the first potential alternative for the treatment of absolute uterine factor infertility (AUFI).

Uterus transplantation and beyond

Uterus transplantation is today the only available treatment for absolute uterine factor infertility which is caused by either congenital/surgical uterine absence or that a present uterus is non-functioning. Structured animal-based research, from rodents to nonhuman primates, was the scientific basis for a successful introduction of uterus transplantation as a clinical procedure. The patient groups for uterus transplantation, the preclinical research and data from the published human cases will be covered herein. During recent years the concept of bioengineering of organs and tissues has emerged. Creation of a bioengineered uterus is in the initial research state, with experiments performed in rodents. The research that has been performed to create a bioengineered uterus will be summarized. In conclusion, uterus transplantation is now a clinical experimental procedure for treatment of uterine factor infertility. In parallel to the establishment of this combined assisted reproduction technique and transplantation procedure as a routine clinical procedure, we predict that uterus bioengineering will develop further towards introduction within the human setting, but that this process will take several years.

Sheep Model for Uterine Transplantation: The Best Option Before Starting a Human Program

OBJECTIVE:

This study reports the first four cases of a uterine transplant procedure conducted in sheep in Latin America. The aim of this study was to evaluate the success of uterine transplantation in sheep.

METHOD:

The study was conducted at Laboratory of Medical Investigation 37 (LIM 37) at the University of São Paulo School of Medicine. Four healthy mature ewes weighing 40-60 kg were used as both the donor and recipient for a transplant within the same animal (auto-transplant). Institutional guidelines for the care of experimental animals were followed.

RESULTS:

The first two cases of auto-transplant were performed to standardize the technique. After complete uterine mobilization and isolation of the blood supply, the unilateral vascular pedicle was sectioned and anastomosed on the external iliac vessels. After standardization, the protocol was implemented. Procurement surgery was performed without complications or bleeding. After isolation of uterine arteries and veins as well as full mobilization of the uterus, ligation of the distal portion of the internal iliac vessels was performed with subsequent division and end-to-side anastomosis of the external iliac vessels. After vaginal anastomosis, the final case presented with arterial thrombosis in the left uterine artery. The left uterine artery anastomosis was re-opened and flushed with saline solution to remove the clot from the artery lumen. Anastomosis was repeated with restoration of blood flow for a few minutes before another uterine artery thrombosis appeared on the same side. All four animals were alive after the surgical procedure and were euthanized after the experimental period.

CONCLUSION:

We describe the success of four uterine auto-transplants in sheep models.

Tacrolimus in the prevention of adverse pregnancy outcomes and diabetes-associated embryopathies in obese and diabetic mice

BACKGROUND

T2DM is a high-risk pregnancy with adverse fetal and maternal outcomes including repeated miscarriages and fetal malformations. Despite the established association between placental insufficiency and poor maternal Th1-adaptability to the development of pregnancy complications in T2DM, there have been no established data to assess benefits of pre-pregnancy immunosuppression relative to gestational outcomes in T2DM. We hypothesized that pre-pregnancy macrolide immune suppression can re-establish normal placental development and uterine vascular adaptation in a mouse model of obesity-associated T2DM.

METHODS

Fetal live birth rate, postnatal variability, mid-gestational uterine and umbilical flow dynamics and certain morphological features of spiral artery modification were examined in the New Zealand Obese (NONcNZO10/Ltj) female mice (n = 56) weaned to ages of 32 weeks on a 60% calories/g high-fat diet (also referred to as HFD-dNONcNZO), and which received either tacrolimus (0.1 mg/kg s.c. q2d) , its vehicle (castor oil and ethanol) or metformin (in drinking water 200 mg/dL p.o. ad libitum). HFD-BALBc-Rag2/IL2-gc female mice (n = 24) were used as HFD-immunodeficient controls.

RESULTS

Treatment of the HFD-dNONcNZO female mice with tacrolimus improved live birth rates and postnatal viability scores (p < 0.01), normalized OGTT (p < 0.001), inhibited fetal malformation rates, restored morphology of spiral arterial modification; and improved uterine arterial and umbilical blood flow (p < 0.01). Placental production of TNFαand IL16 in the tacrolimus-treated HFD-dNONcNZO dams were restored to non-diabetic levels and the treatment resulted in the inhibition of aberrant monocyte/macrophage activation during pregnancy in the HFD-dNONcNZO dams.

CONCLUSIONS

Our present data suggest a casual association between chronic maternal overnutrition and aberrancy in the maternal Th1-immune maladaptation to pregnancy and defective spiral artery modification, placental insufficiency and adverse fetal outcomes in the T2DM subjects. Further safety studies into the use of tacrolimus in the pre-pregnancy glycemic control may be beneficial.

Uterus Transplantation: Current State and Future Perspectives

Absolute uterine factor infertility (AUFI) has traditionally been regarded as untreatable. Gestational surrogacy (GS) is not permitted in most countries and societies in the world due to ethical, religious or legal reasons. The interest in uterus transplantation (UTx) as a treatment for AUFI started in the 1960s and, after some disappointing results, raised again in the new century, when our and other groups obtained live off-spring after UTx in the mouse, and here we review extensively the results of animal research. In September 2014, the first baby was born after human UTx and this proof-of-concept of UTx as an infertility treatment has been followed by several more births. All cases described in the literature are also reviewed.

The overall evidence suggests that the clinical introduction of UTx as the first available treatment for AUFI has been successful. However, UTx will stay at experimental stage for several years whilst optimizing the procedure and ensuring its safety from a medical and psychological perspective.

Human uterus transplantation in focus

INTRODUCTION

Uterus transplantation (UTx) is introduced as the first treatment for absolute uterine factor infertility (AUFI), affecting 1:500 fertile aged women. This review presents potential patients, research and human UTx cases.

SOURCES OF DATA

Published articles and our research experience.

AREAS OF AGREEMENT

The first UTx live births in 2014 established UTx as a possible treatment for AUFI. This was proceeded by 15 years of systematic research.

AREAS OF CONTROVERSY

Is a deceased donor UTx as effective as the proven successful live donor UTx?.

GROWING POINTS

Human UTx trials will accumulate data on risks, effectiveness and long-term consequences for donors, recipients and children. These should also include aspects of quality of life, psychological well-being and cognitive/neuropsychiatric development of children.

AREAS TIMELY FOR DEVELOPING RESEARCH

All new activities in human UTx within the coming years should be conducted as prospective observational studies, and data should also be collected within an international registry.

Special issues in fertility preservation for gynecologic malignancies

Gynecologic malignancies account for 1,09 million new cancer cases worldwide consisting of about 12% of tumors affecting female population. About 10% of all female cancer survivors are younger than 40 years of age. Since cancers affecting female genital organs are usually treated by radical surgery, chemotherapy or chemoradiation approaches that induce permanent damage of reproductive functions, the development of strategies for fertility preservation represent one of the most important goals for gynecologic oncology. In this scenario, the newly defined oncofertility discipline acquires increasing interest, offering patients maximal chances to make an adequate decision about future fertility, based on their oncologic diagnosis and prognosis. However, the majority of physicians do not pay particular attention to these issues, even if impressive progresses have been made in this field in the last decades. Possibly, it is due to the lack of strong evidences from clinical trials without an adequate number of cases to establish safety and efficacy of these procedures. In this review we will discuss the most recently debated options for fertility preservation in gynecologic oncology, highlighting issues and controversies related to oncofertility.