Uterus Transplantation: A Rapidly Expanding Field

Adult outcomes of urinary, sexual functions and fertility after pediatric management of differences in sex development: Who should be followed and how?

The management of Differences of Sex Development (DSD) has evolved considerably in recent years. The questioning of systematic early childhood treatment of DSD requires a better understanding of the outcomes of such treatments and long-term studies are therefore essential to better evaluate the prognosis of DSD. Unfortunately, limitations are numerous including the limited size of the series, the absence of standardized methodology, the evaluation of managements that no longer take place today and the absence of prospective and comparative studies. Despite these difficulties, the purpose of this paper is to present the current data on the long-term follow-up of patients with DSD from the urological, sexual and fertility points of view. Even if it remains difficult at present to establish precise recommendations, we recapitulate the most important points that should drive follow-up of these patients especially the constitution of a multidisciplinary team with a holistic approach, the organization of the transition between adolescence and adulthood, a particular attention to psychological care, a careful communication with the patients and his/her family and the use of standardized data collection systems.

Determination of Maximum Tolerable Cold Ischemia Time in a Mouse Model of Cervical Heterotopic Uterus Transplantation

BACKGROUND

Uterus transplantation (UTx) is an emerging treatment for uterine factor infertility. Determining the maximum tolerable cold ischemia time is crucial for successful UTx. However, the limit for cold ischemia in the uterus is unclear. This study aimed to examine cold ischemia's effects on mouse uteri and identify the maximum cold ischemia duration that uteri can endure.

METHODS

We systematically assessed the tolerance of mouse uteri to extended cold ischemia, 24 h, 36 h, and 48 h, using the cervical heterotopic UTx model. Multiple indicators were used to evaluate ischemia-reperfusion injury, including reperfusion duration, macroscopic examination, oxidative stress, inflammation, and histopathology. The function of transplants was evaluated through estrous cycle monitoring and embryo transfer.

RESULTS

Mouse uteri subjected to 48 h of cold ischemia exhibited significant delays and insufficiencies in reperfusion, substantial tissue necrosis, and loss of the estrous cycle. Conversely, uteri that underwent cold ischemia within 36 h showed long survival, regular estrous cycles, and fertility.

CONCLUSIONS

Our study demonstrated that mouse uteri can endure at least 36 h of cold ischemia, extending the known limits for cold ischemia and providing a pivotal reference for research on the prevention and treatment of cold ischemic injury in UTx.

Normothermic Machine Perfusion Systems: Where Do We Go From Here?

Normothermic machine perfusion (NMP) aims to preserve organs ex vivo by simulating physiological conditions such as body temperature. Recent advancements in NMP system design have prompted the development of clinically effective devices for liver, heart, lung, and kidney transplantation that preserve organs for several hours/up to 1 d. In preclinical studies, adjustments to circuit structure, perfusate composition, and automatic supervision have extended perfusion times up to 1 wk of preservation. Emerging NMP platforms for ex vivo preservation of the pancreas, intestine, uterus, ovary, and vascularized composite allografts represent exciting prospects. Thus, NMP may become a valuable tool in transplantation and provide significant advantages to biomedical research. This review recaps recent NMP research, including discussions of devices in clinical trials, innovative preclinical systems for extended preservation, and platforms developed for other organs. We will also discuss NMP strategies using a global approach while focusing on technical specifications and preservation times.

Uterine Transplantation and Fertility Preservation: A Hopeful Horizon for Cancer Survivors

Uterine transplantation, a groundbreaking medical intervention, stands as a beacon of hope for cancer survivors grappling with the dual challenges of a cancer diagnosis and potential fertility loss due to aggressive treatments. This review provides a comprehensive exploration of uterine transplantation as an innovative solution for fertility preservation in the context of cancer survivorship. The multifaceted discussion encompasses the impact of cancer on fertility, the imperative of fertility preservation, and the evolution of uterine transplantation as a transformative procedure. The post-transplantation care section delves into the intricacies of recovery, the delicate balance of immunosuppressive therapy, and the ongoing support required for recipients to embrace the full spectrum of reproductive possibilities and overall well-being. Ethical considerations surrounding uterine transplantation, including donor selection, risk assessment, and societal perspectives, are critically examined to navigate the ethical landscape of this evolving field. In conclusion, uterine transplantation is presented as a medical breakthrough and a symbol of interdisciplinary collaboration, resilience, and unwavering hope. The review underscores the role of collaborative efforts among medical professionals, researchers, ethicists, and psychologists in advancing this transformative field. Looking to the future, uterine transplantation signifies a paradigm shift in fertility preservation, offering a tangible path toward parenthood for cancer survivors. The procedure, grounded in science, ethics, and compassion, illuminates the way forward, inspiring a future where fertility preservation becomes an attainable reality for those whose reproductive dreams were once compromised by cancer treatments.

Current Status of Tissue Regenerative Engineering for the Treatment of Uterine Infertility

With the recent developments in tissue engineering, scientists have attempted to establish seed cells from different sources, create cell sheets through various technologies, implant them on scaffolds with various spatial structures, or load scaffolds with cytokines. These research results are very optimistic, bringing hope to the treatment of patients with uterine infertility. In this article, we reviewed articles related to the treatment of uterine infertility from the aspects of experimental treatment strategy, seed cells, scaffold application, and repair criteria so as to provide a basis for future research.

[Uterine transplantation, ethical and social aspects]

Uterine transplantation is now a possible treatment for absolute uterine infertility. It is currently proposed to women with Mayer-Rokitansky-Küster-Hauser syndrome but indications will likely to expand in the upcoming years. Despite the progressive standardization of the surgical technique and the reduction in perioperative morbidity for both donors and recipients, the number of transplants performed worldwide remains very low compared to the number of women potentially in need. This is partly due to the singularity of uterine transplantation: the uterus is not a vital organ since one can live without a uterus. It is a temporary transplantation that is not performed to extend life but to improve its quality, responding above all to a desire to conceive and bear a child. Beyond the strictly technical aspect, these particularities raise many ethical questions, both on an individual and social level, which should make us question the real place uterine transplantation should take in our society. Answering these questions will allow us to provide better guidance for future eligible couples and to anticipate ethical problems on the long run.

Etiology, Risk Factors, and Management of Asherman Syndrome

Asherman syndrome is characterized by a triad of symptoms including pain, menstrual abnormalities, and infertility and is a result of intrauterine scar tissue after instrumentation of a gravid uterus. Saline sonohysterogram is typically the most sensitive diagnostic tool; however, hysteroscopy is the criterion standard for diagnosis. Treatment includes hysteroscopic-guided lysis of adhesion, with restoration of the anatomy of the uterine cavity. Several modalities are used in an attempt to reduce the reformation of scar tissue after surgery; however, there is no consensus on the ideal method. Stem cells and platelet-rich plasma are being explored as means of regenerative therapy for the endometrium, but data remain limited. At present, most individuals can have restoration of menstrual function; however, lower pregnancy rates and obstetric complications are not uncommon. These complications are worse for patients with a higher grade of disease. Efforts are needed in standardizing classification, reducing uterine instrumentation of the gravid uterus, and referring patients to health care professionals with clinical expertise in this area.

Imaging of Uterine Transplantation

Uterus transplantation (UTx) is a novel procedure being studied as a treatment of absolute uterine factor infertility. Imaging plays an important role throughout the life cycle of a uterus transplant. In this review, we will first describe the surgical technique of UTx. The article will then focus on the importance of imaging in the evaluation of potential recipients and donors and during the immediate post-surgical time course as graft viability is established. Imaging as part of including in vitro fertilization, pregnancy, and complications will also be discussed.

Uterus Transplantation as a Surgical Innovation

Uterus transplantation (UTx) research has been introduced in several countries, with trials in Sweden and the United States producing successful outcomes. The growing interest in developing UTx trials in other countries, such as Spain, the Netherlands, Japan, and Australia, raises important questions regarding the ethics of surgical innovation research in the field of UTx. This paper examines the current state of UTx in the context of the surgical innovation paradigm and IDEAL framework and discusses the ethical challenges faced by those considering the introduction of new trials. We argue that UTx remains an experimental procedure at a relatively early stage of the IDEAL framework, especially in the context of de novo trials, where protocols are likely to deviate from those used previously and where researchers are likely to have limited experience of UTx. We conclude that countries considering the introduction of UTx trials should build on the strengths of the reported outcomes to consolidate the evidence base and shed light on the uncertainties of the procedure. Authorities responsible for the ethical governance of UTx trials are advised to draw on the ethical framework used in the oversight of surgical innovation.

Pregnancy management and outcome after uterus transplantation

Uterus transplantation is a novel approach in women whose uterus is absent or severely abnormal. However, it is still an experimental procedure that poses risks to both mother and baby. To date, 32 live births after uterus transplantation have been reported in peer-reviewed journals, with several maternal, fetal and neonatal complications. The most common complications were preterm delivery, hypertensive disorders and placenta previa. Four patients experienced episodes of transplant rejection during pregnancy. The appropriate management of complicated and non-complicated pregnancies following uterus transplantation is still unresolved. In this review, obstetric outcomes after uterus transplantation and optimal management during pregnancy are discussed in light of the available data. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Ethical considerations regarding penis transplantation surgery in transgender men-an empirical ethics study

Background

The ongoing quest to surgically create the (nearly) ideal neophallus in transgender men has led to the continuous development of transgender medicine and the proposed introduction of penis transplantation. However, both technical and ethical issues arise when developing this treatment.

Aim

We sought to extract ethical considerations among different stakeholder groups regarding penile transplantation surgery in transgender men and to define preliminary clinical recommendations.

Methods

Three semistructured focus groups, consisting of different stakeholders, were organized to participate in discussions of ethical considerations retrieved from the ethics literature of transplantation and transgender medicine. Analysis of the results was performed according to empirical ethics.

Outcomes

Study outcomes were the identification of qualitative themes describing ethical considerations pertaining to penile transplantation in transgender men.

Results

Nineteen people participated in this qualitative study. The main domains that emerged included arguments in favor of and arguments against penile transplantation. Although the participants expressed positive attitudes toward developing this care, with acknowledgement of the current limitations stakeholders of all groups were reluctant to endorse the introduction of penile transplantation for transgender men at this point.

Clinical Implications

Under the present circumstances, all groups expressed both a wide variety of ethical considerations as well as a tendency to prefer developing alternative treatment options or improving the results of currently available treatments in relation to penile transplantation for transgender men.

Strengths and Limitations

This study was the first (empirical) study to focus on this topic and included a diversity of stakeholder perspectives. Limitations included the hypothetical nature of the discussion as well as the clinical setting in which the topic has been studied.

Conclusion

Introducing penile transplantation for transgender men, under the current circumstances, comes with a wide range of ethical considerations, which deal with personal identity, autonomy, medical risks, risk for transgender support and donor willingness, and issues regarding equality. Despite the present hesitancy to use penile transplantation, should the technical side of this treatment option develop, further research in the ethical field of penile transplantation for transgender men is recommended.

Analysis of Predictive Factors for Successful Vascular Anastomoses in a Sheep Uterine Transplantation Model

Uterine transplantation is becoming an increasingly realistic therapeutic for uterine infertility. Surgical training on large animal models such as sheep is a prerequisite for establishing a program in humans. The objective of our study was to analyze the predictive factors for successful vascular anastomoses. We performed 40 autotransplants that involved end-to-side anastomoses from the uterine to the external iliac vessels. We analyzed vessel results in terms of success or failure; a total of 78.7% of arterial and 82.9% of venous anastomoses were successful in the immediate postoperative period. In multivariate analysis, independent factors associated with immediate successful vein anastomoses were as follows: a short warm ischemia time (<2 h, OR = 0.05; 95% CI [0.003−0.88], p = 0.04), the absence of any anastomotic complications (OR = 0.06; 95% CI [0.003−0.099], p = 0.049), and their realization by a vascular surgeon (OR = 29.3; 95% CI [1.17−731.9], p = 0.04). Secondly, we showed that an increase in lactate levels greater than 2.72 mmol/L, six hours after reperfusion was predictive of failure, with a sensibility of 85.7% and a specificity of 75.0%. In order to perfect the management of vascular anastomoses by a vascular surgeon, training on animal models and in microsurgery are mandatory in establishing a uterine transplantation program in humans.

Uterine Factor Infertility, a Systematic Review

Uterine factor infertility (UFI) is defined as a condition resulting from either a complete lack of a uterus or a non-functioning uterus due to many causes. The exact prevalence of UFI is currently unknown, while treatments to achieve pregnancy are very limited. To evaluate the prevalence of this condition within its different causes, we carried out a worldwide systematic review on UFI. We performed research on the prevalence of UFI and its various causes throughout the world, according to the PRISMA criteria. A total of 188 studies were included in qualitative synthesis. UFI accounted for 2.1 to 16.7% of the causes of female infertility. We tried to evaluate the proportion of the different causes of UFI: uterine agenesia, hysterectomies, uterine malformations, uterine irradiation, adenomyosis, synechiae and Asherman syndrome, uterine myomas and uterine polyps. However, the data available in countries and studies were highly heterogenous. This present systematic review underlines the lack of a consensual definition of UFI. A national register of patients with UFI based on a consensual definition of Absolute Uterine Factor Infertility and Non-Absolute Uterine Factor Infertility would be helpful for women, whose desire for pregnancy has reached a dead end.

Uterus Transplantation: Revisiting the Question of Deceased Donors versus Living Donors for Organ Procurement

Uterus transplantation is a surgical treatment for women with congenital or acquired uterine factor infertility. While uterus transplantation is a life-enhancing transplant that is commonly categorized as a vascular composite allograft (e.g., face or hand), it is similar to many solid organ transplants (e.g., kidney) in that both living donors (LDs) and deceased donors (DDs) can be utilized for organ procurement. While many endpoints appear to be similar for LD and DD transplants (including graft survival, time to menses, livebirth rates), there are key medical, technical, ethical, and logistical differences between these modalities. Primary considerations in favor of a LD model include thorough screening of donors, enhanced logistics, and greater donor availability. The primary consideration in favor of a DD model is the lack of physical or psychological harm to a living donor. Other important factors, that may not clearly favor one approach over the other, are important to include in discussions of LD vs. DD models. We favor a stepwise approach to uterus transplantation, one in which programs first begin with DD procurement before attempting LD procurement to maximize successful organ recovery and to minimize potential harms to a living donor.

A review of the effects of estrogen and epithelial-mesenchymal transformation on intrauterine adhesion and endometriosis

Uterus transplantation has become an option for women suffering from some form of infertility. Current review discusses key physiological functions of the endometrium requiring the transition of tissue cells between the mesenchyme and epithelial cell phenotype, a process known as epithelial-mesenchymal transition (EMT). Estrogen and EMT play a key role in the pathogenesis and treatment of intrauterine adhesion and endometriosis. There is also a close regulatory relationship between estrogen and EMT, and investigation of this relationship is of great significance for the treatment of endometrial disorders. The present review discusses the effects of estrogen on endometrial dysfunction, with a focus on the relationship between estrogen and EMT in endometrial disorders, taking into consideration the mechanisms by which receptors that regulate their functions and proteins that regulate their local biological functions interact with the factors involved in EMT. In addition, the review summarizes emerging drugs targeting receptors or proteins and provides information on the direction of new therapies for endometrial disorders.

Resveratrol inhibits the inflammatory response and oxidative stress induced by uterine ischemia reperfusion injury by activating PI3K-AKT pathway

Uterus transplantation is a complex surgical procedure. Uterine ischemia reperfusion (I/R) injury that occurs during this process may cause a loss of function of the uterus and the failure of transplantation. Resveratrol (RSV) is a naturally occurring polyphenol found abundantly in the skin of grapes and red wine, and it has also been used as a dietary supplement in clinical practice. RSV possesses strong anti-inflammatory and anti-oxidative effects, and exhibits a role in immune system regulation. However, the role of RSV in protecting the uterus against I/R-induced injury is yet to be fully elucidated. The aim of the present study was to investigate the effects and mechanisms underlying RSV in I/R-induced uterus injury. A total of 48 Sprague-Dawley rats were randomly divided into four groups: Control (sham operation) group, the uterus I/R group, the 20 mg/kg RSV-pre-treated I/R (I/R+RSV/20) group and the 40 mg/kg RSV-pre-treated I/R (I/R+ RSV/40) group. A regular I/R model was established to induce uterus injury in rats. RSV at 20 or 40 mg/kg was intraperitoneally administrated into rats in both I/R+ RSV groups once per day for five consecutive days prior to ischemia. The control and I/R only groups received an intraperitoneal injection of the vehicle (ethanol) for the same period prior to ischemia. Samples from blood and uterine horns were collected 3 h after reperfusion. Changes in the levels of malondialdehyde, interleukin (IL)-6, tumor necrosis factor-α, IL-10 and IL-37 were determined using ELISA, the activity levels of myeloperoxidase, catalase, and superoxidase dismutase were also determined using ELISA, the protein expression levels of PI3K, phosphorylated (p)-PI3K, AKT and p-AKT were determined using western blot analysis, and the uterine histology was investigated using H&E staining. Results of the present study demonstrated that treatment with RSV increased the capacity of antioxidants and suppressed uterine oxidative injury induced by I/R. Moreover, treatment with RSV decreased the levels of pro-inflammatory cytokines and increased the levels of anti-inflammatory cytokines. In addition, RSV promoted the phosphorylation of PI3K and AKT, thus activating the PI3K-AKT signaling pathway. Therefore, administration of RSV prior to uterine I/R effectively alleviated inflammatory response and oxidative stress via activation of the PI3K-AKT pathway, suggesting that RSV may play a protective role in I/R-induced uterus injury.

Endometrial organoids derived from Mayer-Rokitansky-Küster-Hauser syndrome patients provide insights into disease-causing pathways

The uterus is responsible for the nourishment and mechanical protection of the developing embryo and fetus and is an essential part in mammalian reproduction. Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by agenesis of the uterus and upper part of the vagina in females with normal ovarian function. Although heavily studied, the cause of the disease is still enigmatic. Current research in the field of MRKH mainly focuses on DNA-sequencing efforts and, so far, has been unable to decipher the nature and heterogeneity of the disease, thereby holding back scientific and clinical progress. Here, we developed long-term expandable organoid cultures from endometrium found in uterine rudiment horns of MRKH patients. Phenotypically, they share great similarity with healthy control organoids and are surprisingly fully hormone responsive. Transcriptome analyses, however, identified an array of dysregulated genes that point to potentially disease-causing pathways altered during the development of the female reproductive tract. We consider the endometrial organoid cultures to be a powerful research tool that promise to enable an array of studies into the pathogenic origins of MRKH syndrome and possible treatment opportunities to improve patient quality of life.

Uterine Transplantation: Recipient Patient Populations

Uterine transplantation is an emerging treatment for patients with uterine factor infertility (UFI). In order to determine patient candidacy for transplant, it is imperative to understand how to identify, counsel and treat uterine transplant recipients. In this article, we focus on patient populations with UFI, whether congenital or acquired, including Mayer-Rokitansky-Kuster-Hauser, complete androgen insensitivity syndrome, hysterectomy, and other causes of nonabsolute UFI. Complete preoperative screening of recipients should be required to assess the candidacy of each individual prior to undergoing this extensive treatment option.

Uterus transplantation: the importance of uterine natural killer cells

PURPOSE OF REVIEW

Murine studies have established that uterine natural killer (uNK) cells are critical regulators of normal placentation and fetal development in mammals. However, the biology of uNK cells in humans remains poorly understood. This ignorance represents a costly knowledge gap, as disordered placentation is thought to underpin a variety of pregnancy complications that impact maternal and neonatal health. In the context of uterus transplantation (UTx), uNK cells are anticipated to play a critical role within the allograft. Here, we review the current understanding of uNK cells in pregnancy biology and explore how this critically important cell population may contribute to pregnancy and graft outcomes in uterus transplant recipients.

RECENT FINDINGS

Recent studies have characterized differences in NK cell populations between anatomic compartments in humans. In the endometrium, at least five phenotypically and functionally distinct subpopulations of uNK cells have been identified, with research into mechanisms regulating their differentiation and function currently underway.

SUMMARY

Further elucidating uNK cell biology has the potential to influence the outcomes of pregnancy and UTx and benefit human health. UTx is a unique opportunity to study uNK cell biology and may shed light on mechanisms by which immunological tolerance is established at the maternal-fetal interface.

Uterus procurement from deceased donor for transplantation

Women with absolute uterine factor infertility cannot get pregnant. The current experience in uterine transplantation is limited and the use of a deceased donor uterus in this area is incipient after some initial unsuccessful attempts. The birth of healthy babies through this modality in four different centers has given a new impetus to the use of this transplantation technique. We aimed to develop a technique for uterus procurement and preparation for transplantation from a brain dead donor. Fifteen uteri were retrieved from multi-organ donor patients, 10 of these were used in bench surgeries with the proposed technique. All procedures were performed after obtaining family's consent. This study allowed the clinical use of two of the 15 organs that were procured for transplantation. One of these organs resulted in the first live birth worldwide using a uterus transplanted from a deceased donor, a landmark in reproductive medicine. Another outcome was the optimization of the surgical technique involving less manipulation of the uterine vascular pedicles. The success of this novel technique suggests that the proposed model can be replicated and optimized further to facilitate the transplantation of uterus from deceased donors.

Internal radial perfusion bioreactor promotes decellularized and recellularization of rat uterine tissue

The advances in infertility treatment technologies such as in vitro fertilization (IVF) help many infertile women to be able to get pregnant. However, these infertility treatments cannot be applied to women who are suffering from absolute uterine factor. Fabrication of functional scaffold in tissue engineering approach is believed to play an important role for uterine regeneration and uterus replacement for treating absolute uterine factor infertility. In this research, we developed an internal radial perfusion bioreactor to promote decellularization and recellularization for fabrication of functional engineered uterine tissue. As a result, the DNA contents of the decellularized uterine tissue with high hydrostatic pressure followed by 7 days internal perfusion washing decreased by 90% compared to native tissue. Collagen and proteoglycan contents in the pressurized uterine tissue with the internal perfusion bioreactor, static (control) and shaking treatment with high hydrostatic pressure showed no significant change compared to the native tissue. The newly developed perfusion bioreactor also enabled to recellularize in the decellularized tissue with statistically significant increase of DNA by 614% compared to non-seeded cell groups. Vimentin and 4',6-diamidino-2-phenylindole (DAPI) was homogeneously expressed in the seeded endometrial stromal cells in the recellularized tissue fabricated using the bioreactor. With the developed internal radial perfusion bioreactor, we are the first group to successfully recellularized uterine tissue in all layers including epithelium, endometrium and myometrium. These results showed that the internal perfusion bioreactor has potential to be utilized for fabrication of functional engineered tissue to promote tissue regeneration.

Evolution and Transformation of Uterine Transplantation: A Systematic Review of Surgical Techniques and Outcomes

BACKGROUND

 Uterine transplantation (UTx) is acknowledged to be on the second (2A) of five steps of development in accordance with the staging system for the evaluation of surgical innovations. Accordingly, we aimed to systematically review the available evidence of the surgical techniques and outcomes of UTx in terms of graft survival.

METHODS

 A comprehensive search was conducted across PubMed Medline, Cochrane-EBMR, Scopus, Web of Science, and CENTRAL through November 2020.

RESULTS

 Forty studies, reporting 64 recipients and 64 donors, satisfied inclusion criteria. The surgical time and the estimated blood loss were 515 minutes and 679 mL for graft procurement via laparotomy, 210 minutes and 100 mL for laparoscopic-assisted graft harvest, and 660 minutes and 173 mL for robotic-assisted procedures, respectively. Urinary tract infections (n = 8) and injury to the urinary system (n = 6) were the most common donor complications. Using the donor's internal iliac system, two arterial anastomoses were performed in all cases. Venous outflow was accomplished through the uterine veins (UVs) in 13 cases, a combination of the UVs and the ovarian/uteroovarian veins (OVs/UOVs) in 36 cases, and solely through the OVs/UOVs in 13 cases. Ischemia time was 161 and 258 minutes when using living donors (LD) and deceased donors (DD), respectively. Forty-eight uteri were successfully transplanted or fulfilled the purpose of transplantation, 41 from LDs and 7 from DDs. Twenty-five and four live childbirths from LDs and DDs have been reported, respectively.

CONCLUSION

 UTx is still experimental. Further series are required to recommend specific surgical techniques that best yield a successful transplant and reduce complications for donors and recipients.

Uterine Tissue Engineering: Where We Stand and the Challenges Ahead

Tissue engineering is an innovative approach to develop allogeneic tissues and organs. The uterus is a very sensitive and complex organ, which requires refined techniques to properly regenerate and even, to rebuild itself. Many therapies were developed in 20th century to solve reproductive issues related to uterus failure and, more recently, tissue engineering techniques provided a significant evolution in this issue. Herein we aim to provide a broad overview and highlights of the general concepts involved in bioengineering to reconstruct the uterus and its tissues, focusing on strategies for tissue repair, production of uterine scaffolds, biomaterials and reproductive animal models, highlighting the most recent and effective tissue engineering protocols in literature and their application in regenerative medicine. In addition, we provide a discussion about what was achieved in uterine tissue engineering, the main limitations, the challenges to overcome and future perspectives in this research field.

Building a stem cell-based primate uterus

The uterus is the organ for embryo implantation and fetal development. Most current models of the uterus are centred around capturing its function during later stages of pregnancy to increase the survival in pre-term births. However, in vitro models focusing on the uterine tissue itself would allow modelling of pathologies including endometriosis and uterine cancers, and open new avenues to investigate embryo implantation and human development. Motivated by these key questions, we discuss how stem cell-based uteri may be engineered from constituent cell parts, either as advanced self-organising cultures, or by controlled assembly through microfluidic and print-based technologies.

Uterine transplant: an ethical framework analysis from a Middle Eastern perspective

BACKGROUND

Significant advances in infertility treatment have been achieved over the past several decades, but women with uterine dysfunction, anomaly, or agenesis still need support to carry a pregnancy to term. Recently, advancements in surgical, anesthetic and immunosuppressive therapy have brought the idea of successful uterine transplant closer to reality, but many challenges must be overcome before uterine transplant can become more common, including ethical challenges related to the study and the conduct of this procedure.

METHODS

This was an updated ethical analysis of uterine transplant from a Middle Eastern perspective, using an established ethical framework that has been adapted for the analysis of research in non-Western cultures and developing countries.

RESULTS

Using the ethical framework, this analysis explored research developments in uterine transplant to date, using the following categories: collaborative partnership, social value, scientific validity, a fair selection of study population, favorable risk-benefit ratio, independent review, informed consent, and respect for recruited participants. The analysis revealed a significant need for region- and religion-specific ethical guidelines for uterine transplant procedures.

CONCLUSIONS

The horizons of research need to expand by addressing and researching the ethical issues related to uterine transplant trials and clinical procedures.

LIMITATIONS

Limitations included the challenges related to applying ethical analyses to work in developing countries, and the fact that this analysis was based on the views and interpretations of a single researcher.

Immune response after allogeneic transplantation of decellularized uterine scaffolds in the rat

Data on how the immune system reacts to decellularized scaffolds after implantation is scarce and difficult to interpret due to many heterogeneous parameters such as tissue-type match, decellularization method and treatment application. The engraftment of these scaffolds must prove safe and that they remain inert to the recipient's immune system to enable successful translational approaches and potential future clinical evaluation. Herein, we investigated the immune response after the engraftment of three decellularized scaffold types that previously showed potential to repair a uterine injury in the rat. Protocol (P) 1 and P2 were based on Triton-X100 and generated scaffolds containing 820 ng mg^-1and 33 ng mg^-1donor DNA per scaffold weight, respectively. Scaffolds obtained with a sodium deoxycholate-based protocol (P3) contained 160 ng donor DNA per mg tissue. The total number of infiltrating cells, and the population of CD45⁺leukocytes, CD4⁺T-cells, CD8a⁺cytotoxic T-cells, CD22⁺B-cells, NCR1⁺NK-cells, CD68⁺and CD163⁺macrophages were quantified on days 5, 15 and 30 after a subcutaneous allogenic (Lewis to Sprague Dawley) transplantation. Gene expression for the pro-inflammatory cytokines INF-γ, IL-1β, IL-2, IL-6 and TNF were also examined. P1 scaffolds triggered an early immune response that may had been negative for tissue regeneration but it was stabilized after 30 d. Conversely, P3 initiated a delayed immune response that appeared negative for scaffold survival. P2 scaffolds were the least immunogenic and remained similar to autologous tissue implants. Hence, an effective decellularization protocol based on a mild detergent was advantageous from an immunological perspective and appears the most promising for futurein vivouterus bioengineering applications.

Preimplantation genetic testing for aneuploidy in uterus transplant patients

Uterus transplantation is an emerging treatment for uterine factor infertility. In vitro fertilization with cryopreservation of embryos prior is required before a patient can be listed for transplant. Whether or not to perform universal preimplantation genetic testing for aneuploidy should be addressed by centers considering a uterus transplant program. The advantages and disadvantages of preimplantation genetic testing for aneuploidy in this unique population are presented. The available literature is reviewed to determine the utility of preimplantation genetic testing for aneuploidy in uterus transplantation protocols. Theoretical benefits of preimplantation genetic testing for aneuploidy include decreased time to pregnancy in a population that benefits from minimization of exposure to immunosuppressive agents and decreased chance of spontaneous abortion requiring a dilation and curettage. Drawbacks include increased cost per in vitro fertilization cycle, increased number of required in vitro fertilization cycles to achieve a suitable number of embryos prior to listing for transplant, and a questionable benefit to live birth rate in younger patients. Thoughtful consideration of whether or not to use preimplantation genetic testing for aneuploidy is necessary in uterus transplant trials. Age is likely a primary factor that can be useful in determining which uterus transplant recipients benefit from preimplantation genetic testing for aneuploidy.

Bioengineering of the Uterus

Impairment of uterine structure and function causes infertility, pregnancy loss, and perinatal complications in humans. Some types of uterine impairments such as Asherman’s syndrome, also known as uterine synechiae, can be treated medically and surgically in a standard clinical setting, but absolute defects of uterine function or structure cannot be cured by conventional approaches. To overcome such hurdles, partial or whole regeneration and reconstruction of the uterus have recently emerged as new therapeutic strategies. Transplantation of the whole uterus into patients with uterine agenesis results in the successful birth of children. However, it remains an experimental treatment with numerous difficulties such as the need for continuous and long-term use of immunosuppressive drugs until a live birth is achieved. Thus, the generation of the uterus by tissue engineering technologies has become an alternative but indispensable therapeutic strategy to treat patients without a functional or well-structured uterus. For the past 20 years, the bioengineering of the uterus has been studied intensively in animal models, providing the basis for clinical applications. A variety of templates and scaffolds made from natural biomaterials, synthetic materials, or decellularized matrices have been characterized to efficiently generate the uterus in a manner similar to the bioengineering of other organs and tissues. The goal of this review is to provide a comprehensive overview and perspectives of uterine bioengineering focusing on the type, preparation, and characteristics of the currently available scaffolds.

Options for acquiring motherhood in absolute uterine factor infertility; adoption, surrogacy and uterine transplantation

KEY CONTENT

Following the diagnosis of absolute uterine factor infertility (AUFI), women may experience considerable psychological harm as a result of a loss of reproductive function and the realisation of permanent and irreversible infertility.Adoption enables women with AUFI, and their partners, to experience social and legal parenthood, also often providing benefits for the adopted child.Surrogacy offers the opportunity to have genetically related offspring. Outcomes are generally positive in both surrogates and the children born as a result.Uterine transplantation is the only option to restore reproductive anatomy and functionality. While associated with considerable risk, it allows the experience of gestation and the achievement of biological, social and legal parenthood.

LEARNING OBJECTIVES

To gain an understanding of the routes to parenthood available for women with AUFI experiencing involuntary childlessness, such as adoption, surrogacy and, most recently, uterine transplantationTo consider a suggested management plan to facilitate counselling in women with AUFI who experience involuntary childlessness.

ETHICAL ISSUES

In the UK, while the number of children requiring adoption continues to increase, the number being adopted from care is decreasing.Some cultures may hold ethical or religious beliefs that surrogacy is unacceptable, and its legal position in many jurisdictions is problematic.Restrictive selection criteria and high costs may limit future availability of uterine transplantation.

Infectious complications of vascularized composite allograft transplantation

PURPOSE OF REVIEW

Vascularized composite allograft (VCA) transplants constitute multiple tissues transplanted together as one functional unit. These procedures are increasing in frequency and complexity, yet data about graft survival, quality of life, and infection risk remain limited.

RECENT FINDINGS

Informative guidance for this patient population is often inferred from the solid organ transplantation literature. Yet, it is important to understand that VCA transplantation additionally carries its own significant and distinctive risk factors for infection.

SUMMARY

In this review, we give an overview of previously described infectious complications of VCA transplantation in the literature, discuss risk factors for future infection in these patients, and discuss how to manage such obstacles.

Surrogacy and "Procreative Tourism". What Does the Future Hold from the Ethical and Legal Perspectives?

Background and objectives: To explore the ethical and legal complexities arising from the controversial issue of surrogacy, particularly in terms of how they affect fundamental rights of children and parents. Surrogacy is a form of medically-assisted procreation (MAP) in which a woman "lends" her uterus to carry out a pregnancy on behalf of a third party. There are pathological conditions, such as uterine agenesis or hysterectomy outcomes, that may prevent prospective mothers from becoming pregnant or carry a pregnancy to term; such patients may consider finding a surrogate mother. Many issues relating to surrogacy remain unresolved, with significant disagreements and controversy within the scientific community and public opinion. There are several factors called into play and multiple parties and stakeholders whose objectives and interests need to somehow be reconciled. First and foremost, the authors contend, it is essential to prioritize and uphold the rights of children born through surrogacy and heterologous MAP. Materials and methods: To draw a parallel between Italy and the rest of the world, the legislation in force in twelve European countries was analyzed, eleven of which are part of the European Union (France, Germany, Italy, Spain, Greece, Netherlands, Belgium, Denmark, Lithuania, Czech Republic and Portugal) and three non-members of the same (United Kingdom, Ukraine and Russia), as well as that of twelve non-European countries considered exemplary (United States, Canada, Australia, India, China, Thailand, Israel, Nigeria and South Africa); in particular, legislative sources and legal databases were drawn upon, in order to draw a comparison with the Italian legislation currently in force and map out the evolution of the Italian case law on the basis of the judgments issued by Italian courts, including the Constitutional and Supreme Courts and the European Court of Human Rights (ECHR); search engines such as PubMed and Google Scholar were also used, by entering the keywords "surrogacy" and "surrogate motherhood", to find scientific articles concerning assisted reproduction techniques with a close focus on surrogacy. Results: SM is a prohibited and sanctioned practice in Italy; on the other hand, it is allowed in other countries of the world, which leads Italian couples, or couples from other countries where it is banned, to often contact foreign centers in order to undertake a MAP pathway which includes surrogacy; in addition, challenges may arise from the legal status of children born through surrogacy abroad: to date, in most countries, there is no specific legislation aimed at regulating their legal registration and parental status. Conclusion: With reference to the Italian context, despite the scientific and legal evolution on the subject, a legislative intervention aimed at filling the regulatory gaps in terms of heterologous MAP and surrogacy has not yet come to fruition. Considering the possibility of "fertility tourism", i.e., traveling to countries where the practice is legal, as indeed already happens in a relatively significant number of cases, the current legislation, although integrated by the legal interpretation, does not appear to be effective in avoiding the phenomenon of procreative tourism. Moreover, to overcome some contradictions currently present between law 40 and law 194, it would be appropriate to outline an organic and exhaustive framework of rules, which should take into account the multiplicity of interests at stake, in keeping with a fair and sustainable balance when regulating such practices.

Single bilateral ovarian venous return in uterine transplant: Validation in an orthotopic auto-transplant model in the Yucatan minipig

BACKGROUND

Uterine transplant (UT) represents an opportunity to treat absolute uterine infertility. However, the use of uterine veins for venous return, in addition to ovarian veins, significantly increases the risk of ureteral wounds in the living donor and UT time for the recipient. Our aim was to demonstrate that dual ovarian venous return is sufficient for graft viability and survival.

METHODS

Uterine orthotopic auto-transplant was performed under general anaesthesia in six Yucatan minipig sows. The uterus graft was implanted with termino-lateral anastomoses between the ovarian and external iliac veins, and between the uterine and external iliac arteries, respectively.

RESULTS

The macroscopic physical aspect of the graft was adequate in 83 % of the sows (5/6) 30 min after reperfusion with a surgical time of 439±54 min (mean anastomosis time: 153±49 min). Two sows died the day after surgery. In the four remaining sows, two uteri were necrotic and two were adequately vascularized on Day 7.

CONCLUSIONS

the learning curve was relatively fast, the sole use of bilateral ovarian venous return is possible and might reduce post-surgery morbidity in human living donors as well as UT time for the recipient.

Uterine Transplantation: Evolving Data, Success, and Clinical Importance

Uterine transplantation is an evolving procedure to allow for childbearing in paitents with absolute uterine factor infertility. The objective of this study was to review the existing literature using a comprehensive PubMed literature search. A systematic medical subheadings search strategy was used with the terms "uterus transplant" and "uterine transplantation". Of the 75 full-text articles assessed for eligibility, 68 were included in the qualitative synthesis. Of these, 9 were included in the meta-analysis on living donor uterine transplant, 5 on deceased donor uterine transplant, and 6 case reports of single uterine transplants. In conclusion, uterus transplant is a nascent field undergoing a rapid rate of evolution as programs mature their data and increase the number of procedures performed. The most recent publications and advances are thus summarized in this article to capture the most up-to-date information.

Custodiol-N Is Superior to Custodiol® Solution in Experimental Rat Uterus Preservation

Uterus transplantation (UTx) is the first and only available treatment for women with absolute uterine factor infertility. However, clinical application is limited by the lack of organs, ischemia/reperfusion injury, as well as immunosuppression after UTx. Several different preservation solutions are used in experimental and clinical UTx, including Custodiol^® solution. Recently, the novel Custodiol-N solution was developed with superior results in organ preservation. However, the solution was not tested yet in UTx. Therefore, the aims of this study were to evaluate the effect of Custodiol-N in uterus prolonged cold preservation time (8 and 24 h), compared to Custodiol^® solution. Uterus tissue samples were obtained from adult Sprague Dawley rats (n = 10/group). Cold ischemic injury was estimated by histology, including immunohistochemistry, and biochemical tissue analyses. After 8 h of cold ischemia, higher percentage of tissue edema, necrosis signs and myeloperoxidase expression, as well as lower superoxide dismutase activity were found in Custodiol^® compared to Custodiol-N (p < 0.05). These differences were more pronounced after 24 h of cold preservation time (p < 0.05). This study demonstrated that Custodiol-N protects uterus grafts from cold ischemic injury better than standard Custodiol^® most likely via inhibition of oxidative stress and tissue edema. It seems that iron chelators in the composition of Custodiol-N play an important protective role against cold ischemia.

[Uterus transplantation, current prospect and future indications. State of art with review of literature]

OBJECTIVES

The aim of this review is to summarize the development of UT on worldwide and to develop the new questions posed by this technique in 2020.

METHODS

According to the PRISMA model, via Pubmed, we searched for publications containing the keywords: uterus transplantation; UT and cryopreservation from 2000 to 2020.

RESULTS

At least 76 UTx have been carried out around the world and 19 healthy babies were born. The main indication remains the uterine agenesis (MRKH Syndrome>85% cases) then the history of hysterectomy (hemorrhage of the delivery or cervical cancer) and the non-functional uterus (Asherman's syndrome, diffuse adenomyosis). The 2 types of donors (living and deceased) are developed representing respectively 75% and 25% of the TU; the success rate in terms of return of rules is better in the living donor group and is 79% vs 68% in the deceased donor group. The choice of donor type must take into account the constraints of both procedures. Surgical complications (grade III) for the donor are estimated to be 14% mainly represented by ureter wounds. Technical simplifications concerning the venous return of the graft but also the carrying out of robot-assisted surgery would reduce the operating time for the donor and facilitate the collection process.

CONCLUSION

TU is a complementary alternative to GPA and adoption allowing patients to be surrogates, legal and biological of the baby. An extension of the indications to patients with non absolute uterine infertility is in the process of democratization.

Assisted Reproductive Techniques and Pregnancy Results in Women with Mayer-Rokitansky-Küster-Hauser Syndrome Undergoing Uterus Transplantation: the Czech Experience

STUDY OBJECTIVE

This study aimed to evaluate the reproductive potential of patients with Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) who were candidates for uterus transplantation (UTx) before inclusion in the experimental trial, and to summarize the existing experience with posttransplantation embryo transfers in functionally successful cases.

DESIGN AND SETTING

A prospective study at a tertiary medical center.

PARTICIPANTS

Ten pre-UTx women with MRKHS and 7 successful UTx cases.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Ovarian stimulations, frozen embryo collection, embryo transfers, and incidence of pregnancy in MRKHS women in the pre- and posttransplantation periods.

RESULTS

The average number of ovarian stimulations to collect the required frozen embryos was 1.9 (1-3). On average, the number of aspirated oocytes was 16.4 (7-38), 12.6 (5-26) oocytes were fertilized, and 7.0 (1-18) embryos were cryopreserved per cycle. To date, the average number of embryo transfers per recipient was 4.9 (3-8), and the embryo transfer/pregnancy rate was 8.8% (3 of 34). Three pregnancies have been achieved to date, including a missed abortion in the 8th week, a birth in the 35th week, and an ongoing pregnancy in the 30th week.

CONCLUSIONS

Despite the small number of UTx cases, our data indicated that women with MRKHS showed a good response to ovarian stimulation and blastocyst formation. Although the procedures for fertilization, cryopreservation, and transfer of the embryos were standardized, the success rate per embryo transfer achieved in the study group has been low to date.

First birth from a deceased donor uterus in the United States: from severe graft rejection to successful cesarean delivery

Uterus transplantation is the only known potential treatment for absolute uterine factor infertility. It offers a unique setting for the investigation of immunologic adaptations of pregnancy in the context of the pharmacologic-induced tolerance of solid organ transplants, thus providing valuable insights into the early maternal-fetal interface. Until recently, all live births resulting from uterus transplantation involved living donors, with only 1 prior birth from a deceased donor. The Cleveland Clinic clinical trial of uterus transplantation opened in 2015. In 2017, a 35 year old woman with congenital absence of the uterus was matched to a 24 year old parous deceased brain-dead donor. Transplantation of the uterus was performed with vaginal anastomosis and vascular anastomoses bilaterally from internal iliac vessels of the donor to the external iliac vessels of the recipient. Induction and maintenance immunosuppression were achieved and subsequently modified in anticipation of pregnancy 6 months after transplant. Prior to planned embryo transfer, ectocervical biopsy revealed ulceration and a significant diffuse, plasma cell-rich mixed inflammatory cell infiltrate, with histology interpreted as grade 3 rejection suspicious for an antibody-mediated component. Aggressive immunosuppressive regimen targeting both cellular and humoral rejection was initiated. After 3 months of treatment, there was no histologic evidence of rejection, and after 3 months from complete clearance of rejection, an uneventful embryo transfer was performed and a pregnancy was established. At 21 weeks, central placenta previa with accreta was diagnosed. A healthy neonate was delivered by cesarean hysterectomy at 34 weeks' gestation. In summary, this paper highlights the first live birth in North America resulting from a deceased donor uterus transplant. This achievement underscores the capacity of the transplanted uterus to recover from a severe, prolonged rejection and yet produce a viable neonate. This is the first delivery from our ongoing clinical trial in uterus transplantation, including the first reported incidence of severe mixed cellular/humoral rejection as well as the first reported placenta accreta.

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.

Techniques for successful vaginal anastomosis in the uterine transplantation patient

OBJECTIVE

To demonstrate techniques for successful donor-to-recipient vaginal anastomosis in uterine transplantation including illustration of a tension-free technique.

DESIGN

This video uses live-action footage from surgery, detailed animations, and illustrations to review the step-by-step technique we use for vaginal anastomosis in uterine transplantation. Institutional Review Board approval was obtained for this experimental surgery.

SETTING

Academic medical center.

PATIENT(S)

Patients undergoing uterine transplantation.

INTERVENTION(S)

Preparation of recipient vagina with illustration of challenges and risk secondary to dense adhesions between bladder and neo-vagina. Use of surgical techniques. Key steps include appropriate preparation of both donor and recipient vaginal tissues and a tension-free closure with horizontal mattress stitches.

MAIN OUTCOME MEASURE(S)

Intraoperative techniques in the clinical research trial of uterine transplantation.

RESULTS

Successful vaginal anastomosis in the uterine transplantation patient.

CONCLUSION(S)

This video provides a step-by-step guide to vaginal anastomosis in uterine transplantation patients. Our team has applied techniques from vaginal reconstructive surgery in an attempt to reduce the occurrence of postoperative vaginal strictures, with attention to planned donor and recipient anastomosis site tissue preparation and closure of the anastomosis using a tension-free suturing technique.

Ischemia and reperfusion injury in uterus transplantation: A comprehensive review

Uterus transplantation (UTx) is the only available treatment for human beings who cannot carry children out to term. However, despite several clinical studies with a very limited number of UTx many issues have to be addressed. Up to date, there is a limited number of successful UTx with livebirth and the majority was achieved with live donors. Wide clinical application is inherently limited by the lack of organs, ischemia/reperfusion injury (IRI) as well as immunosuppression after UTx. The objective of this comprehensive literature review is to discuss these arising limitations of UTx with main focus on strategies to reduce IRI. This review showed, that usage of immunosuppressants, opioids or supplements, like amino acids, protects uterus from IRI, improving rising level of antioxidants and decreasing level of oxidative stress markers. The available data of experimental and clinical studies was compiled and will be discussed.

Uterine transplantation and IVF for congenital or acquired uterine factor infertility: A systematic review of safety and efficacy outcomes in the first 52 recipients

Uterine transplantation (UTx) associated with IVF restores fertility in women affected by absolute uterine factor infertility (AUFI). Pregnancies achieved both in women undergoing any solid organ transplantation and following IVF are associated with an increased risk of maternal and neonatal complications. This systematic review evaluated this risk in UTx-IVF treated women focusing on the safety and efficacy features of the treatment. Twenty-two studies and three press releases reporting on 52 UTx-IVF treatments were identified. Regarding the safety of treatment, 38/52 (73,1%) of surgical procedures led to the restoration of uterine function in recipients, 12/52 (23,1%) of recipients experienced post-operative complications requiring hysterectomy, and 2/52 (3,8%) of procedures failed before uterine recipients’ surgery due to intra-operative complications. Regarding the efficacy of treatment, results focused on transplanted patients showing full recovery of organ functioning: 16/38 (42,1%) of patients achieved a pregnancy, including two women who gave births twice. UTx-IVF pregnancies led to 16 deliveries and all new-borns were healthy. Six out of 16 (37,5%) UTx pregnancies faced major complications during gestation. Preterm births occurred in 10/16 (62,5%) UTx deliveries. Our data indicates that the risk of gestational and delivery complications deserves important consideration in AUFI women receiving UTx-IVF treatments. However, these observations are preliminary and need to be revised after larger series of data are published.

Provider Knowledge and Support of Uterus Transplantation: Surveying Multidisciplinary Team Members

Objective

To determine relevant provider opinions on uterus transplantation (UTx).

Patients and Methods

We invited 1933 providers in obstetrics and gynecology, transplant surgery, transplant medicine, internal medicine, and family medicine at a large, integrated health care system to complete an online survey containing a series of questions on their attitudes about the ethics and clinical utility of UTx. The survey was open from June 4, 2018, through July 2, 2018. We received 449 responses overall (23.2% response rate).

Results

Of 433 physicians who responded, 195 (45.0%) believe that UTx is ethically justified, and just over a third (160 of 446 [35.9%]) would introduce the possibility of UTx to a patient with absolute uterine factor infertility (AUFI). Respondents indicated the risks to donor, recipient, and child carried the most weight in their ethical evaluation and were most supportive of UTx in a patient with congenital uterine absence (334 of 743 [45.0%]; participants were allowed to choose more than one answer). A majority stated that a living or cadaveric donor would be an acceptable donor source (238 of 395 [60.3%]).

Conclusion

Provider support for UTx is qualified by safety concerns and its expansion to patient populations other than women with AUFI. This survey suggests that most providers limit their support of UTx to patients with the most demonstrated clinical need, childless women with AUFI.