Uterus transplantation: animal research and human possibilities

Uterus transplantation: A bibliometric review of six-decade study from 1960 to 2024

INTRODUCTION

Some women are unable to become pregnant because they do not have a functional uterus. Over the last decade, it has become possible for these women to get pregnant through uterus transplantation, which has been the subject of numerous research studies. Therefore, the purpose of this study is to review published articles in the uterus transplantation area.

MATERIAL AND METHODS

We conducted a cross-sectional bibliometric review to study the 100 highly cited papers in the Web of Science and Scopus databases from 1960 to 2024. Our research applied bibliometric analysis to these top 100 highly cited papers. Document citation and co-occurrence analysis were used for the data study. VOSviewer along with Bibliometrix® software was used to design the maps.

RESULTS

The trend of uterus transplantation publications increased exponentially after 2010. Sweden is the leading country, followed by the USA and Spain. Fertility and Sterility, Lancet, American Journal of Transplantation, and Human Reproduction were the highly cited journals. Collaboration among countries showed that the most collaboration took place between Sweden and Spain (18), Sweden and the USA (14), the USA and Spain (8), Sweden and Australia (6), and the USA and the United Kingdom (6). Furthermore, the results found that more than one-third of the highly cited papers were review papers (39%) and 27% were clinical trial studies.

CONCLUSIONS

This bibliometric review provides a valuable contribution to the literature on uterine transplantation by synthesizing and analyzing existing research findings. It offers insights into current trends, key themes, geographic distribution, and potential areas for future research within this rapidly evolving field.

Uterus transplantation: A clinical breakthrough after systematic preclinical research

Background

Uterus transplantation is a groundbreaking solution for absolute uterine factor infertility, offering women the potential for full biological motherhood. Since the first human trial in 2012 and the birth of the first baby in 2014, over 140 procedures have been performed globally, resulting in more than 70 live births.

Methods

This review synthesizes data from foundational animal research, patient eligibility criteria, and advancements in surgical techniques for uterus transplantation. It examines live and deceased donor grafts, the role of assisted reproductive technologies, and obstetrical outcomes.

Main Findings

Animal studies have been pivotal in transitioning uterus transplantation into clinical practice. Surgical advancements, including robotic-assisted live donor hysterectomy, have improved precision. Protocols for in vitro fertilization have evolved, optimizing treatment before and after transplantation and reducing the time between transplantation and embryo transfer. Obstetrical outcomes show increased risks, such as hypertensive disorders and preterm births, underscoring the importance of thorough monitoring during pregnancy.

Conclusion

Despite its complexities, uterus transplantation represents a transformative advance in reproductive medicine. It provides a viable path to biological motherhood for women with uterine infertility and marks significant progress in both transplantation and fertility treatments, paving the way for further refinement and broader application.

Perfusion magnetic resonance imaging in Asherman syndrome

BACKGROUND

Microvascular scarring compromises the functionality of the endometrium, and vascular flow at the junctional zone (JZ) may be the key to understanding poor reproductive outcomes in women with Asherman syndrome (AS).

AIMS

To investigate whether vascular perfusion of the uterus, measured by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is impaired in women with intrauterine adhesions (IUA) and AS.

MATERIALS AND METHODS

A prospective observational cohort pilot study of 23 women with IUA treated with hysteroscopic synecholysis and a control group of two patients with cervix cancer were subject to DCE-MRI with gadolinium to assess uterine vascularity. Twelve regions of interest (ROIs) were allocated on the DCE-MRI image incorporating the JZ, with control ROI placed at the psoas muscle. Individual ROIs were compared to the mean total perfusion (TP) in the same uterus. Pre- and post-operative perfusion analyses were performed on five women. Receiver operator curves (ROC) were used to analyse MRI as a predictor of IUA.

RESULTS

There was no significant difference in perfusion; a trend toward reduced perfusion was observed in women with IUA compared to the controls. The ROC was predictive of higher-grade and inoperable IUA.

CONCLUSIONS

Reduced perfusion on DCE-MRI as assessed by ROC predicted higher-stage AS. The results of this study support further investigation of DCE-MRI as a prognostic tool for AS prior to surgical intervention to assist in providing prognostic guidance for women suffering from AS.

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.

Reproductive, obstetric, and long-term health outcome after uterus transplantation: results of the first clinical trial

OBJECTIVE

To evaluate reproductive, obstetric, and long-term health of the first completed study of uterus transplantation (UTx).

DESIGN

Prospective.

SETTING

University hospital.

PATIENT(S)

Nine live donor UTx procedures were conducted and seven were successful. Donors, recipients, and children born were observed.

INTERVENTION(S)

In vitro fertilization was performed with embryo transfer (ET) of day 2 or day 5 embryos in natural cycles. Pregnancies and growth trajectory of the children born were observed. Health-related quality of life, psychosocial outcome, and medical health of donors and recipients were evaluated by questionnaires.

MAIN OUTCOME MEASURE(S)

The results of in vitro fertilization, pregnancies, growth of children, and long-term health of patients were reported.

RESULT(S)

Six women delivered nine infants, with three women giving birth twice (cumulative birth rates of 86% and 67% in surgically successful and performed transplants, respectively). The overall clinical pregnancy rate (CPR) and live birth rate (LBR) per ET were 32.6% and 19.6%, respectively. For day 2 embryos, the CPR and LBR per ET were 12.5% and 8.6%, respectively. For day 5 embryos, the CPR and LBR per ET were 81.8% and 45.4%, respectively. Fetal growth and blood flow were normal in all pregnancies. Time of delivery (median in full pregnancy weeks + days [ranges]) by cesarean section and weight deviations was 35 + 3 (31 + 6 to 38 + 0) and -1% (-13% to 23%), respectively. Three women developed preeclampsia and four neonates acquired respiratory distress syndrome. All children were healthy and followed a normal growth trajectory. Measures of long-term health in both donors and recipients were noted to be favorable. When UTx resulted in a birth, scores for anxiety, depression, and relationship satisfaction were reassuring for both the donors and recipients.

CONCLUSION(S)

The results of this first complete UTx trial show that this is an effective infertility treatment, resulting in births of healthy children and associated with only minor psychological and medical long-term effects for donors and recipients.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02987023.

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.

Uterus transplantation worldwide: clinical activities and outcomes

PURPOSE OF REVIEW

Women with absolute uterine factor infertility, because of uterine absence, or the presence of a nonfunctional uterus, were regarded as being untreatable until 2014 when the first birth following uterus transplantation (UTx) took place in Sweden. This proof-of-concept occurred in a woman with Mayer-Rokitansky-Küster-Hauser syndrome (MRKHs) with congenital uterine absence, who received a uterus from a 61-year-old live donor (LD). Since then, several births after UTx have occurred in Sweden and subsequently in other countries, including both LD and deceased donor (DD) transplants. A great majority of the recipients were women with MRKHs. The efficiency and safety of UTx can be determined only when a complete study cohort of transplanted women have reached the definitive endpoint of graft hysterectomy. The different outcomes of transplanted women include graft failure, as well as graft survival with failure to achieve livebirth, or livebirth(s). Published data from a completed trial are not yet available. The results that we have to rely on are reports of completed surgeries and interim outcomes that may be as early as a few months after surgery and up to several years after UTx. The purpose of this review is to give an update on all published clinical UTx data and major results, including live births up to mid 2021.

RECENT FINDINGS

The interim results of a number of UTx studies have been published. LD UTx procedures have been reported from four European countries (Sweden, the Czech Republic, Germany, Spain), four Asian nations (Saudi Arabia, India, China, Lebanon), as well as some from the USA. DD UTx procedures have been reported from Turkey, the Czech Republic, the USA and Brazil. To our knowledge, there also exist unpublished UTx cases from some of the countries mentioned above and from at least four other countries (Serbia, France, Mexico, Italy). We estimate that at least 80 UTx procedures have been performed, resulting in more than 40 births. The present study includes only data from published, peer-reviewed, research papers. The results of 62 UTx cases show an overall surgical success rate, as defined by a technically successful transplantation with a subsequent regular menstrual pattern, of 76%. The success rates for LD and DD UTx procedures were 78% and 64%, respectively. The rate of serious postsurgical complications requiring invasive or radiological intervention was 18% for LDs and 19% for recipients. The cumulative live birth rate in successful UTx procedures is estimated to be above 80%. Twenty-four births after UTx have been reported and the results show a high rate of preterm birth, with an associated high proportion of respiratory distress syndrome.

SUMMARY

UTx has proven to be a successful treatment for uterine factor infertility at several centers around the world. The modest success rate and the fairly high complication rate among LDs, indicate that further research and development under strict governance are needed before this option should be widely offered.

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.

Uterus transplantation in a sheep model: novel surgical technique with long-term survival and uterus vitality. First case series in Argentina

OBJECTIVE

To develop a sheep autologous uterus transplantation (UT) program with an innovative surgical technique and assess long term uterus vitality and animal survival.

METHODS

A novel surgical technique consisting of the procurement of the complete uterus and the two ovaries, back table vascular reconstruction, and subsequent implantation in the same animal, performing only two arterial and two venous anastomoses.

RESULTS

Four autologous transplantations were performed; anesthesia and surgery were well tolerated by all the animals without complications. Direct observation and Doppler US performed a week after UT and laparoscopy performed three months later confirmed uterus vitality. All animals were alive more than a year after transplantation.

CONCLUSIONS

Our study was the first to describe a novel surgical technique for sheep uterus autologous transplantation in Latin America, showing long-term survival and uterus vitality.

The costs of human uterus transplantation: a study based on the nine cases of the initial Swedish live donor trial

STUDY QUESTION

What are the costs of live donor uterus transplantation in a European setting?

SUMMARY ANSWER

The total costs for preoperative investigations, including IVF, and live donor uterus transplantation including postoperative costs for 2 months, were calculated to be €74 564 (mean), with the costs of recipient being somewhat higher than for donor and the cost components of total costs distributed between sick leave (25.7%), postoperative hospitalization (17.8%), surgery (17.1%), preoperative investigations (15.7%), anaesthesia (9.7%), drugs (7.8%), tests after surgery (4.0%) and for re-hospitalization (2.2%).

WHAT IS KNOWN ALREADY

Uterus transplantation has proved to be successful by demonstrations of live births, both after live donor and deceased donor procedures. The transplantation is considered as a complex and expensive infertility treatment. There exist no analyses of costs involved in uterus transplantation.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included nine uterus transplantations procedures, performed in Sweden in 2013. Study duration of this health economic study included 6-12 months of pre-transplantation investigations and the time interval from transplantation to 2 months after.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Nine triads of uterus recipient, partner of recipient and uterus donor participated. All prospective recipients were in stable relationships and performed IVF with their partners before transplantation. The nine donors were relatives or family friends. The recipients and donors underwent pre-transplantation investigations with imaging, laboratory tests and psychological/medical screening prior to transplantation. Transplantation was by laparotomy in both donor and recipient. Standard immunosuppression and postoperative medication were used. After discharge from the hospital, the recipients were followed frequently with laboratory tests and examinations.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean costs for preoperative investigations, including IVF, and live donor uterus transplantation with postoperative costs for 2 months, were calculated to be €74 564 (range €50 960-€99 658), from a societal perspective. The four largest components were cost of sick leave (€19 164), cost of postoperative hospitalization (€13 246), surgery cost (€12 779) and costs for preoperative investigations, including IVF (€11 739). Smaller components were costs for anaesthesia (€7207), costs for drugs (€5821), costs for post-surgical tests (€2985) and costs for re-hospitalization (€1623). The costs of the recipient (€42 984) were somewhat higher than the costs of the donor (€31 580), but in terms of costs, they should be viewed as one entity. By using a health care perspective, excluding cost for productivity loss, the total costs would be reduced by 26%.

LIMITATIONS, REASONS FOR CAUTION

A limitation is the restricted sample size and that this is in the experimental, clinical stage of development.

WIDER IMPLICATIONS OF THE FINDINGS

The results provide the first information concerning the costs for pre-transplantation investigations and uterus transplantation procedures with postoperative follow-up. We consider the total estimate to be in the higher interval, because of the extensive research protocol. It is likely that the cost of live donor uterus transplantation will vary between countries and that the costs will be lower in a future clinical setting.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from the Jane and Dan Olsson Foundation for Science; the Knut and Alice Wallenberg Foundation; an ALF grant from the Swedish state under an agreement between the government and the county councils; and the Swedish Research Council. None of the authors have a conflict of interest with regard to the study.

TRIAL REGISTRATION NUMBER

NCT01844362.

Novel approaches in uterus transplantation

PURPOSE OF REVIEW

Uterus transplantation (UTx) is the first existing infertility treatment for women with no uterus and for women with a present nonfunctional uterus, which is unable to carry a pregnancy. This type of transplantation is a novel addition within the field of vascularized composite allografts and is the first ephemeral kind of transplantation, with the graft intended for only a restricted number of years, until the desired numbers of children have been born and with subsequent graft removal. The proof-of-concept of UTx, as an infertility treatment for women with uterine factor infertility, came with the report of the first live birth after UTx, occurring in Sweden in 2014. This UTx live birth has been followed by around 30 births, taking place in four continents. Despite the initial clinical success, UTx should still be regarded as an experimental procedure, at a developmental phase. The clinical UTx activities at several centers around the globe take place within scientific clinical trials and aim to advance UTx further. This review describes certain developmental areas around UTx. These relate to surgery, donor selection, assisted reproduction, and inclusion of new recipient groups.

RECENT FINDINGS

Successful UTx procedures, with live births, have been reported both after live and deceased donor transplantation. There exist developments in the areas of robotic surgery for live donor hysterectomy, of alternate vascular connections to the graft, modifications of inclusion criteria/investigations of donors, assisted reproduction in conjunction with UTx, as well as discussions concerning expanding the pool of eligible recipients.

SUMMARY

Uterus transplantation has repeatedly proven to be a feasible infertility treatment for women with absolute uterine factor infertility. Ongoing studies aim to increase safety and efficiency of the procedure as well as to better define suitable donors and recipients.

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.

Towards uterus tissue engineering: a comparative study of sheep uterus decellularisation

Uterus tissue engineering may dismantle limitations in current uterus transplantation protocols. A uterine biomaterial populated with patient-derived cells could potentially serve as a graft to circumvent complicated surgery of live donors, immunosuppressive medication and rejection episodes. Repeated uterine bioengineering studies on rodents have shown promising results using decellularised scaffolds to restore fertility in a partially impaired uterus and now mandate experiments on larger and more human-like animal models. The aim of the presented studies was therefore to establish adequate protocols for scaffold generation and prepare for future in vivo sheep uterus bioengineering experiments. Three decellularisation protocols were developed using vascular perfusion through the uterine artery of whole sheep uteri obtained from slaughterhouse material. Decellularisation solutions used were based on 0.5% sodium dodecyl sulphate (Protocol 1) or 2% sodium deoxycholate (Protocol 2) or with a sequential perfusion of 2% sodium deoxycholate and 1% Triton X-100 (Protocol 3). The scaffolds were examined by histology, extracellular matrix quantification, evaluation of mechanical properties and the ability to support foetal sheep stem cells after recellularisation. We showed that a sheep uterus can successfully be decellularised while maintaining a high integrity of the extracellular components. Uteri perfused with sodium deoxycholate (Protocol 2) were the most favourable treatment in our study based on quantifications. However, all scaffolds supported stem cells for 2 weeks in vitro and showed no cytotoxicity signs. Cells continued to express markers for proliferation and maintained their undifferentiated phenotype. Hence, this study reports three valuable decellularisation protocols for future in vivo sheep uterus bioengineering experiments.

Targeting connexins with Gap27 during cold storage of the human donor uterus protects against cell death

Uterus transplantation is an experimental infertility treatment for women with uterine factor infertility. During donor uterus retrieval and subsequent storage, ischemia and other stressors are likely to occur, resulting in the delayed restoration of organ function and increased graft rejection. The uterus expresses connexin-based hemichannels, the opening of which can promote ischemic cell death, as well as gap junctions that may expand cell death by bystander signaling. We investigated if connexin channel inhibition with connexin channel inhibitor Gap27 could protect the uterus against cell death during the storage period. The study involved 9 female patients undergoing gender-change surgery. Before uterus removal, it was exposed to in situ warm ischemia with or without reperfusion. Uterus biopsies were taken before, during, and after ischemia, with or without reperfusion, and were subsequently stored under cold (4ᵒC) or warm (37ᵒC) conditions. TUNEL cell death assay was done at various time points along the combined in vivo/ex vivo experimental timeline. We found that Gap27 protected against storage-related cell death under cold but not warm conditions when the uterus had experienced in situ ischemia/reperfusion. For in situ brief ischemia without reperfusion, Gap27 reduction of cell death was delayed and significantly less, suggesting that protection critically depends on processes initiated when the organ was still in the donor. Thus, the inclusion of the connexin channel inhibitor Gap27 during cold storage protects the uterus against cell death, and the degree of protection depends on the history of exposure to warm ischemia. Gap27 protection may be indicated for uteri from deceased donors, in which ischemia is likely because life-saving organs have retrieval priority.

Report of the first live birth after uterus transplantation in People's Republic of China

OBJECTIVE

To present the first live birth after uterine transplantation (UTx) in the People's Republic of China.

DESIGN

Case study.

SETTING

University hospital.

PATIENT(S)

A 22-year-old woman with Mayer-Rokitansky-Kuster-Hauser syndrome and previous surgery for vaginal reconstruction and UTx.

INTERVENTION(S)

Endometrial preparation, frozen embryo transfer, pregnancy follow-up, and cesarean section.

MAIN OUTCOME MEASURE(S)

Results of in vitro fertilization, frozen embryo transfer, ultrasound measurements during pregnancy, rejection diagnosis and treatment, delivery, live birth, and histology of uterus.

RESULTS(S)

Frozen embryo (cleavage stage) transfer started 1.5 years after UTx. The first embryo transfer (n = 2) resulted in a biochemical pregnancy. The second, third, and fourth embryo transfer (n = 2, 2, 3) did not result in pregnancy. The fifth embryo transfer (n = 3) resulted in pregnancy with two gestational sacs, but with spontaneous disappearance of one in early pregnancy. During early pregnancy three episodes of vaginal bleedings occurred (gestational weeks 6 + 2, 13 + 1, and 16 + 3), with a spontaneously resorbing subchorionic hematoma diagnosed at the last bleeding episode. Bleeding episodes were treated with corticosteroids and tacrolimus. During pregnancy, blood flow velocity waveforms and fetal growth parameters were normal. A subacute cesarean section was performed at gestational week 33 + 6 due to uterine contraction pattern suggesting imminent labor. A healthy boy (2,000 g) with Apgar scores of 10, 10, 10 was delivered. The uterus was kept for a possible second pregnancy.

CONCLUSION(S)

The first live birth after UTx in the People's Republic of China is reported and this occurred after a robotic-assisted laparoscopic uterus retrieval from the mother.

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.

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.

Novel Technique in a Sheep Model of Uterine Transplantation

INTRODUCTION

Uterine transplantation (UTx) is a surgical therapeutic modality designed for the treatment of patients with exclusive uterine factor infertility. Experimental models are paramount to study this transplant modality, and as the ewes' uteri are very similar to that of humans, they are frequently used with this purpose. The aim of this study is to describe a novel technical variation for UTx in sheep.

METHODS

This study was conducted at Laboratory of Medical Investigation 37 of the University of São Paulo School of Medicine in São Paulo, Brazil, and was approved by the Ethics Committee of Animal Use of the university. We used 3 adult female sheep that weighed approximately 45 kg and were not pregnant. We performed the technique of uterine autotransplantation with a novel technical variation that we called sequential vascularization: first, we performed the right uterine artery and vein anastomoses, after which the uterine graft was vascularized, and then the contralateral vascular anastomoses were performed.

CONCLUSION

We described 3 successful uterine autotransplants in sheep models with sequential vascularization. This variation technique will probably allow warm ischemia time in UTx to significantly decrease.

New Frontier: Role of the Radiologist in Uterine Transplantation

Uterine transplantation (UT) is a novel treatment for absolute uterine factor infertility (AUFI) that is currently being performed under experimental protocols in multiple medical centers worldwide. At the time of this publication, there have been at least 10 live births by women with a transplanted uterus. As successful outcomes from this innovative procedure increase, it is likely that more centers will perform UT. Imaging is performed in multiple steps of the UT process, including preoperative imaging of potential donors and recipients, posttransplant surveillance, and monitoring of pregnancy. Fetal imaging is performed by maternal-fetal medicine professionals, but most imaging examinations in UT are performed by radiologists. Given the significant role of imaging in this groundbreaking surgery, radiologists must be familiar with the causes of AUFI and the role of imaging in establishing this diagnosis. Radiologists working in medical centers where UT is performed should understand the role of imaging in preoperative planning and postoperative surveillance. While data regarding complications of UT are preliminary at best, radiologists must be aware of the risk of vascular compromise and graft failure and their imaging features. The authors provide a brief history of UT and define the radiologist's role in pre- and postoperative imaging assessments.^©RSNA, 2019.

Laparoscopic uterine graft procurement and surgical autotransplantation in ovine model

Currently, uterus transplantation (UTx) is a clinical option for infertile women. Over the past three decades, treating benign or malignant gynecological diseases with minimally invasive gynecological surgery has improved, providing significant advantages over conventional open surgery. This study addresses the method used for laparoscopic live-donor ovariohysterectomy and graft harvest from a sheep model. Using a microsurgical practice, ten grafts were autotransplanted after uterine perfusion. End-to-end anastomosis techniques were used to approximate veins and arteries. Follow-ups were carried out 2-months after surgery and postoperative studies included ultrasound scan, diagnostic hysteroscopy, vascular angiography, and exploratory laparoscopy. All transplants were completed without complications. After vascular anastomosis, total reperfusion of the tissue was accomplished in all animals without confirmation of arterial or venous thrombosis. Angiographic explorations did not show any statistically significant dissimilarity in the arterial diameters between the different examination times. 3-months after uterine transplantation all animals underwent assisted reproduction techniques. Patent uterine arteries were observed 4, 8 and 12 months after the transplant. 6-months after transplantation, six sheep (60%) became pregnant with assisted reproduction practices. We noticed an increase in the degree of fibrosis of the cervix samples in non-pregnant animals of the transplant group. Laparoscopic surgery can be an advantageous approach for the uterus retrieval procedure during uterine transplantation. However, larger sample sized reports are needed in order to accomplish validation, standardization and wider use of this route.

Screening and evaluation of potential recipients and donors for living donor uterus transplantation: results from a single-center observational study

OBJECTIVE

To report our experience with the screening and selection of potential recipients and living donors of our uterus transplantation (UTx) program.

DESIGN

Part of an observational program.

SETTING

University hospital.

PATIENT(S)

Patients with absolute uterine factor infertility (AUFI).

INTERVENTION(S)

Screening by e-mail and telephone, selection during surgical consultation, and preoperative investigations according to a multistep procedure for living donation.

MAIN OUTCOME MEASURE(S)

Age, cause of AUFI, exclusion reasons, and preoperative workup.

RESULT(S)

A total of 212 potential recipients expressed interest in participation. Among the 46 potential recipients and 49 directed donors were 4 potential recipients, each with 2 directed donors. Mean (range) age of potential recipients was 29.6 (19-41) years. Of the potential recipients, 39 (84.8%) had congenital AUFI and 7 (17.3%) had acquired AUFI. Ultimately, 15 potential recipients with 16 directed donors were selected for participation, with 1 potential recipient having 2 directed donors. Mean age of included potential recipients was 28.9 (22-35) years, and mean donor age was 51.3 (37-62) years. Fourteen potential recipients (93.3%) had congenital AUFI, and one potential recipient (6.7%) had undergone hysterectomy for obstetric complications.

CONCLUSION(S)

The number of potential candidates for UTx is not inconsiderable, with congenital AUFI being the leading cause of AUFI in our cohort. However, our findings highlight that large numbers of AUFI patients need to be screened, considering our exclusion rates were >50%, owing to ABO incompatibility, unavailability of a directed donor, and self-withdrawal. Moreover, meticulous preoperative screening, including in-depth psychological assessment, is mandatory to maximize living donor safety and UTx success.

Intra- and Postoperative Blood Flow Monitoring in a Sheep Model of Uterus Transplantation

BACKGROUND

The introduction of the opportunity to transplant a viable uterus into women for fulfilling their desire to have a child has awakened high expectations worldwide.

MATERIALS AND METHODS

A sheep model was used to evaluate tools for optimizing measurement of blood flow in uterine transplantation. Intraoperatively, blood flow was measured using unidirectional Doppler and indocyanine green (ICG) fluorescence imaging. Postoperatively, an implantable Doppler probe served as a tool for clinical monitoring the patency of anastomosed vessels.

RESULTS

ICG imaging showed complete vascularization of the uterus before and in short-term evaluation after surgery. The implantable Doppler probe proved to be highly suitable for assessing patency of vessels in a non-invasive way. Results of histology, and real-time polymerase chain reaction demonstrated viability of the transplanted uterus.

CONCLUSION

Different methods to monitor vasculature patency have proven to be advantageous in supporting both surgeons and researchers in ensuring successful implementation of uterine transplantation.

Uterine transplantation: Review in human research

Uterine transplantation is the solution to treat absolute uterine fertility. In this review, we present the historical, medical, technical, psychological and ethical perspectives in human uterine transplantation research. We reviewed the PubMed database following PRISMA guidelines and added data presented by several research teams during the first international congress on uterine transplantation.

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.

Nonhuman Primates: A Vital Model for Basic and Applied Research on Female Reproduction, Prenatal Development, and Women's Health

The comparative biology of reproduction and development in mammalian species is remarkable. Hence, because of similarities in environmental and neuroendocrine control of the reproductive axis, the cyclic function of the ovary and reproductive tract, establishment and control of the maternal-fetal-placental unit during pregnancy, and reproductive aging from puberty through menopause, nonhuman primates (NHPs) are valuable models for research related to women's reproductive health and its disorders. This chapter provides examples of research over the past 10+ years using Old World monkeys (notably macaque species), baboons, and to a lesser extent New World monkeys (especially marmosets) that contributed to our understanding of the etiology and therapies or prevention of: (1) ovarian disorders, e.g., polycystic ovary syndrome, mitochondrial DNA-based diseases from the oocyte; (2) uterine disorders, for example, endometriosis and uterine transplantation; and (3) pregnancy disorders, for example, preterm labor and delivery, environmental factors. Also, emerging opportunities such as viral (e.g., Zika) induced fetal defects and germline genomic editing to generate valuable primate models of human diseases (e.g., Huntington and muscular dystrophy) are addressed. Although the high costs, specialized resources, and ethical debate challenge the use of primates in biomedical research, their inclusion in fertility and infertility research is vital for continued improvements in women's reproductive health.

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.

Modified human uterus transplantation using ovarian veins for venous drainage: the first report of surgically successful robotic-assisted uterus procurement and follow-up for 12 months

OBJECTIVE

To report the 12-month results of the first human uterus transplantation case using robot-assisted uterine retrieval. This type of transplantation may become a treatment for permanent uterine factor infertility.

DESIGN

Case study.

SETTING

University hospital.

PATIENT(S)

A 22-year-old woman with complete müllerian agenesis who underwent a previous surgery for vaginal reconstruction. The live uterine donor was her mother.

INTERVENTION(S)

The uterus transplantation procedure consisted of robot-assisted uterine procurement, orthotopic replacement and fixation of the retrieved uterus, revascularization, and end-to-side anastomoses of bilateral hypogastric arteries and ovarian-uterine vein to the bilateral external iliac arteries and veins.

MAIN OUTCOME MEASURE(S)

Data from preoperative investigations, surgery, and follow-up (12 months).

RESULT(S)

The duration of the donor and recipient surgeries were 6 and 8 hours, 50 minutes, respectively. No immediate perioperative complications occurred in the recipient or donor. The recipient experienced menarche 40 days after transplant surgery, and she has had 12 menstrual cycles since the surgery. No rejection episodes occurred in the recipient.

CONCLUSION(S)

These results demonstrate the feasibility of live-donor uterine transplantation with a low-dose immunosuppressive protocol and the role of DaVinci robotic assistance during human uterine procurement.

CLINICAL TRIAL REGISTRATION NUMBER

XJZT12Z06.

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.

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.

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.

Uterine Tissue Engineering and the Future of Uterus Transplantation

The recent successful births following live donor uterus transplantation are proof-of-concept that absolute uterine factor infertility is a treatable condition which affects several hundred thousand infertile women world-wide due to a dysfunctional uterus. This strategy also provides an alternative to gestational surrogate motherhood which is not practiced in most countries due to ethical, religious or legal reasons. The live donor surgery involved in uterus transplantation takes more than 10 h and is then followed by years of immunosuppressive medication to prevent uterine rejection. Immunosuppression is associated with significant adverse side effects, including nephrotoxicity, increased risk of serious infections, and diabetes. Thus, the development of alternative approaches to treat absolute uterine factor infertility would be desirable. This review discusses tissue engineering principles in general, but also details strategies on how to create a bioengineered uterus that could be used for transplantation, without risky donor surgery and any need for immunosuppression. We discuss scaffolds derived from decellularized organs/tissues which may be recellularized using various types of autologous somatic/stem cells, in particular for uterine tissue engineering. It further highlights the hurdles that lay ahead in developing an alternative to an allogeneic source for uterus transplantation.

Uterine transplantation: a systematic review

Up to 15% of the reproductive population is infertile, and 3 to 5% of these cases are caused by uterine dysfunction. This abnormality generally leads women to consider surrogacy or adoption. Uterine transplantation, although still experimental, may be an option in these cases. This systematic review will outline the recommendations, surgical aspects, immunosuppressive drugs and reproductive aspects related to experimental uterine transplantation in women.

Multispectral imaging of organ viability during uterine transplantation surgery in rabbits and sheep

Uterine transplantation surgery (UTx) has been proposed as a treatment for permanent absolute uterine factor infertility (AUFI) in the case of the congenital absence or surgical removal of the uterus. Successful surgical attachment of the organ and its associated vasculature is essential for the organ’s reperfusion and long-term viability. Spectral imaging techniques have demonstrated the potential for the measurement of hemodynamics in medical applications. These involve the measurement of reflectance spectra by acquiring images of the tissue in different wavebands. Measures of tissue constituents at each pixel can then be extracted from these spectra through modeling of the light–tissue interaction. A multispectral imaging (MSI) laparoscope was used in sheep and rabbit UTx models to study short- and long-term changes in oxygen saturation following surgery. The whole organ was imaged in the donor and recipient animals in parallel with point measurements from a pulse oximeter. Imaging results confirmed the re-establishment of adequate perfusion in the transplanted organ after surgery. Cornual oxygenation trends measured with MSI are consistent with pulse oximeter readings, showing decreased StO2 immediately after anastomosis of the blood vessels. Long-term results show recovery of StO2 to preoperative levels.

Multispectral imaging of organ viability during uterine transplantation surgery in rabbits and sheep

Uterine transplantation surgery (UTx) has been proposed as a treatment for permanent absolute uterine factor infertility (AUFI) in the case of the congenital absence or surgical removal of the uterus. Successful surgical attachment of the organ and its associated vasculature is essential for the organ’s reperfusion and long-term viability. Spectral imaging techniques have demonstrated the potential for the measurement of hemodynamics in medical applications. These involve the measurement of reflectance spectra by acquiring images of the tissue in different wavebands. Measures of tissue constituents at each pixel can then be extracted from these spectra through modeling of the light–tissue interaction. A multispectral imaging (MSI) laparoscope was used in sheep and rabbit UTx models to study short- and long-term changes in oxygen saturation following surgery. The whole organ was imaged in the donor and recipient animals in parallel with point measurements from a pulse oximeter. Imaging results confirmed the re-establishment of adequate perfusion in the transplanted organ after surgery. Cornual oxygenation trends measured with MSI are consistent with pulse oximeter readings, showing decreased StO2 immediately after anastomosis of the blood vessels. Long-term results show recovery of StO2 to preoperative levels.

Psychological Issues Associated With Absolute Uterine Factor Infertility and Attitudes of Patients Toward Uterine Transplantation

CONTEXT

Uterine transplantation (UTx).

OBJECTIVE

To explore patients' knowledge of and attitudes toward UTx before and after a short educational intervention via a video and question and answer (Q&A) session.

DESIGN

Large, in-depth survey investigating patients' motivations, aims, and beliefs on UTx.

SETTING

Imperial College London.

PARTICIPANTS

Women diagnosed with absolute uterine factor infertility (AUFI) who were seeking information on UTx and had already volunteered to participate in the study.

INTERVENTION

A semistructured interview involving a brief baseline questionnaire before a Q&A session and a 20-minute video exploring the main risks and benefits for UTx.

MAIN OUTCOME MEASURES

Attitudes of self-referred patients with AUFI toward UTx before and after education focusing on UTx. Rank order of importance of key UTx-related issues.

RESULTS

Forty women were interviewed. Following the video presentation and Q&A session, 97.5% (n = 39) would undergo UTx ahead of surrogacy and adoption in full knowledge that the latter 2 options would be ultimately safer for their own well-being and the fact that the graft could fail even prior to conception. All felt that UTx should take place, and 92.5% saw UTx as achievable.

CONCLUSION

The study demonstrates a keen interest in UTx, partly because other options seem difficult to access. It is worth noting that people appear to be distancing themselves from the risk. This requires careful assessment in any clinical program. This study is the first to demonstrate a qualitative relationship between patients with AUFI and their curiosity and desire for UTx. It paves the way for forming the introduction into the psychological assessment of a potential patient.