Human Uterus Transplantation from Living and Deceased Donors: The Interim Results of the First 10 Cases of the Czech Trial

Living-Donor Uterus Transplantation: A Clinical Review

Uterus transplantation (UTx) is currently the only available treatment for absolute uterine factor infertility. More than 90 uterus transplantations have been performed worldwide, mostly from living donors. Living-donor (LD) UTx is a challenging surgical procedure since it poses ethical issues, and it is a high-risk and invasive surgery with higher hysterectomy-related risks compared to conventional hysterectomy. A total of 59 living-donor hysterectomies have been reported in the literature, including 35 performed with a laparotomic approach, 20 with a robotic approach and 4 with a laparoscopic approach. The mean donor age was 45.6 ± 9.1 years, and 22 were unrelated with the recipients, 34 were emotionally related (27 mothers, 5 sisters, 2 mother's sisters). The mean recipient age was 28.8 ± 4.5 years. Mayer-Rokitansky-Küster-Hauser syndrome was the most common indication for uterus transplant. Robotic living-donor hysterectomy had the longest operative time but resulted in a lower blood loss and postoperative stay compared to laparotomic and laparoscopic approaches. Twenty-nine births from LD-UTx have been reported, four after robotic living-donor hysterectomy and twenty-five after a laparotomic procedure. UTx is now an effective treatment for women with UFI. While living-donor UTx in some cases may be considered an experimental procedure, it offers the extraordinary possibility to give women the opportunity to have a pregnancy. Many efforts should be made to reduce the potential risks for donors, including the use of mini-invasive techniques, and the efficacy of UTx in the recipients, giving the potential harm of immunosuppression in a recipient of a non-life-saving organ.

Unique risk factors for unplanned preterm delivery in the uterus transplant recipient

STUDY QUESTION

Do characteristics of the lower uterine segment and cervix modify the risk of preterm delivery in uterus transplant (UTx) recipients?

SUMMARY ANSWER

The cervical length showed little association with preterm delivery, however, cervical inflammation deserves further exploration as a cause of preterm delivery.

WHAT IS KNOWN ALREADY

UTx recipients do not have the risk factors normally used to stratify pregnancies that would benefit from cervical length assessment. In addition, unique factors related to absent tissues, a different blood supply, inflammatory processes of rejection, cervical biopsies, and a different microbiome challenge the normal progressive remodeling of the cervix and thus cervical competence.

STUDY DESIGN, SIZE, DURATION

This is a subanalysis of a clinical trial of 20 women undergoing uterus transplantation at Baylor University Medical Center from 2016 to 2020, in addition to two women who received transplantation outside of a research protocol at our institution through September 2022. In this report, the first 16 UTx recipients that achieved live birth are included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The focus of this study was 20 pregnancies that reached the second trimester in 16 women following UTx. We analyzed recipient, transplant, and donor factors to determine if characteristics were associated with delivery outcome. We compared obstetrical outcomes, including planned versus unplanned delivery, by factors such as number of superior venous anastomoses, warm ischemia and cold ischemia times, donor factors including cesarean sections, cervical biopsy results, and cervical ultrasound results.

MAIN RESULTS AND THE ROLE OF CHANCE

Planned term deliveries occurred in 44% (8/18) of live births. Of the preterm births, 30% (3/10) were planned and 70% (7/10) were unplanned. Unplanned deliveries occurred in women with spontaneous preterm labor, severe rejection, subchorionic hematoma, and placenta previa. Cervical length in UTx recipients averaged 33.5 mm at 24 weeks and 31.5 mm at 28 weeks, comparable to values from the general population. No relationship was seen between delivery outcome and number of veins used, ischemic time, or number of previous cesarean sections.

LIMITATIONS, REASONS FOR CAUTION

The study's small size allows limited conclusions. The obstetric history of all donors was limited to mode of delivery.

WIDER IMPLICATIONS OF THE FINDINGS

Cervical length measurements in the UTx population are not expected to deviate from those with a native uterus. While cervical length surveillance remains important, attention must be paid to the results of cervical biopsies which are obtained to monitor rejection. Inflammatory processes seem most predictive of preterm delivery.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was provided for this study. The authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

NCT02656550.

Miracles of science: Birth after uterus transplantation

AIM

The concept of regaining childbearing ability via uterus transplantation (UTx) motivates many infertile women to pursue giving birth to their own children. This article provides insight into maternal and neonatal outcomes of the procedure globally and facilitates quality of care in related medical fields.

METHODS

The authors searched ISI Web of Science, MEDLINE, non-PubMed-indexed journals, and common search engines to identify peer-review publications and unpublished sources in scientific reference databases.

RESULTS

The feasibility of the procedure has been proven with 46 healthy children in 88 procedures so far. Success relies upon dedicated teamwork involving transplantation surgery, obstetrics and reproductive medicine, neonatology, pediatrics, psychology, and bioethics. However, challenges exist owing to donor, recipient, and fetus. Fetal growth in genetically foreign uterine allograft with altered feto-maternal interface and vascular anatomy, immunosuppressive exposure, lack of graft innervation leading to "unable-to-feel" uterine contractions and conception via assisted reproductive technology create notable risks during pregnancy. Significant portion of women are complicated by at least one or more obstetric problems. Preeclampsia, gestational hypertension and diabetes mellitus, elevated kidney indices, and preterm delivery are common complications.

CONCLUSIONS

UTx has short- and long-term satisfying outcome. Advancements in the post-transplant management would undoubtedly lead this experimental procedure into mainstream clinical practice in the near future. However, both women and children of UTx need special consideration due to prematurity-related neonatal problems and the long-term effects of transplant pregnancy. Notable health risks for the recipient and fetus should be discussed with potential candidates for UTx.

Hypothermic machine perfusion for uterus transplantation

OBJECTIVE

To describe the feasibility of hypothermic machine perfusion (HMP) in uterus transplantation (UT) to potentially improve the preservation of the uterus and enhance graft preservation in the donation after brainstem death (DBD) context. Uterus transplantation is a new surgical approach to treating absolute uterine infertility; it can be performed after living donation or after DBD. In the DBD context, the uterus is typically the last organ removed after other vital organs, with the exception of the Baylor team, which removes the uterus first. This key aspect imposes an unavoidable mild temperature ischemia for >1 hour on the uterus during the removal of the vital abdominal and chest organs. In renal transplantation, the perfusion machine reduces the risk of delayed graft function; thus, we hypothesized that machine perfusion could result in a reduction of uterus graft dysfunction. The uterus graft dysfunction could be expressed by a low embryo implantation rate, pregnancy loss, or vascular pregnancy diseases such as preeclampsia or fetal growth restriction." To date, static cold storage of the uterus is the only standard method for preservation before transplantation. HMP is an emerging method that could potentially improve the preservation of the uterus to enhance graft preservation in the DBD context.

DESIGN

This video article shows all the technical details of using the HMP for uterine transplantation.

SETTING

University.

ANIMALS

Porcine model.

INTERVENTION

Porcine uterus was retrieved from a DBD domestic animal model and flushed with KPS MP (Bridge To Life Ltd in UK) at 4 °C. After vascular preparation on the back table, the uterus was perfused using KPS MP through a cannula in the aorta using the VitaSmart device (Bridge To Life Ltd in UK) for 18 hours. Then, the uterus was transplanted to the porcine recipient.

MAIN OUTCOME MEASURES

The macroscopic appearance of the uterus at the end of HMP and the assessment of the uterus vascularization after transplantation in the recipient compared with the native uterus.

RESULTS

This video shows the cannulation of the iliac vessels, cooling and removal of the uterus on a porcine model, uterus preservation using HMP during 18 hours, and then UT in a new recipient pig with the reperfusion of the transplanted uterus next to the native, intact uterus of the recipient. The macroscopic appearance of the uterus at the end of HMP appeared viable and was perfectly flushed. The assessment of the uterus vascularization after transplantation in the recipient was similar to that of the native uterus. To our knowledge, we describe here for the first time the UT procedure in DBD context on an animal model and the use of HMP for uterus preservation in UT programs; this could increase the number of uterine grafts available for a greater number of female recipients.

CONCLUSION

Hypothermic machine perfusion could allow the duration of cold ischemia to be prolonged without altering the uterine graft. Nevertheless, this assertion has to be validated in a human context.

Reproducibility of Rejection Grading in Uterus Transplantation: A Multicenter Study

Background

Diagnosis of rejection after uterus transplantation is based on histopathological examination of ectocervical biopsies. Inflammation at the stromal-epithelial interface is the backbone of the histopathological classification proposed by our group in 2017. However, the reproducibility of this grading scheme has not been tested, and it is unclear whether it covers the full morphological spectrum of rejection.

Methods

We present a multicenter study in which 5 pathologists from 4 uterus transplantation centers performed 2 rounds of grading on 145 and 48 cervical biopsies, respectively. Three of the centers provided biopsies. Additionally, the presence of perivascular stromal inflammation was recorded. During discussions after the first round, further histological lesions (venous endothelial inflammation and apoptosis) were identified for closer evaluation and added to the panel of lesions to score in the second round. All participants completed a questionnaire to explore current practices in handling and reporting uterus transplant biopsies.

Results

Cervical biopsies were commonly performed in all centers to monitor rejection. Intraobserver reproducibility of rejection grading (performed by 1 rater) was excellent, whereas interobserver reproducibility was moderate and did not improve in the second round. Reproducibility of perivascular stromal inflammation was moderate but unsatisfactory for venous endothelial inflammation and apoptosis. All lesions were more frequent in, but not restricted to, biopsies with rejection patterns.

Conclusions

Grading of rejection in cervical biopsies is reproducible and applicable to biopsies from different centers. Diagnosis of rejection may be improved by adding further histological lesions to the grading system; however, lesions require rigorous consensus definition.

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

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

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.

Who should provide the uterus? The ethics of live donor recruitment for uterus transplantation

Uterus transplantation (UTx) is an experimental surgery likely to face the issue of organ shortage. In my article, I explore how this issue might be addressed by changing the prevailing practices around live uterus donor recruitment. Currently, women with children - often the mothers of recipients - tend to be overrepresented as donors. Yet, other potentially eligible groups who may have an interest in providing their uterus - such as transgender men, or cisgender women who do not wish to gestate or to have children - tend to be excluded as potential donors. Moving forward, I recommend that donor inclusion criteria for UTx be broadened to be more inclusive of these latter groups.

Graft Failure after Uterus Transplantation in 16 Recipients: A Review

Uterus transplantation (UTx) is now an alternative to surrogacy and adoption for women with uterine factor infertility to have children; however, there are still unresolved clinical and technical issues. One of these is that the graft failure rate after transplantation is somewhat higher than that of other life-saving organ transplants, which is a critical concern. Herein, we summarize the details of 16 graft failures after UTx with living or deceased donors using the published literature in order to learn from these negative outcomes. To date, the main causes of graft failure are vascular factors (arterial and/or venous thrombosis, atherosclerosis, and poor perfusion). Many recipients with thrombosis develop graft failure within one month of surgery. Therefore, it is necessary to devise a safe and stable surgical technique with higher success rates for further development in the UTx field.

Differences between living and deceased donation in human uterus transplantation: A narrative review

The decision to use a living or deceased donor to perform uterus transplantation (UTx) is an evaluation of benefit and harm and is based on the medical team's choices. The current study determines the differences between living and deceased donation in human UTx according to determinant factors in choosing the donor type. For this review study, the PubMed database was searched without time, language, and location limitations up to May 2022. From 113 identified articles, 45 papers were included in the study for review. According to the results, in comparison to living donation, the biggest advantage of deceased donation is the lack of surgical and or psychological risks for the donor. In contrast, a comprehensive pre-transplantation medical assessment is less possible in deceased donation, and preplanned surgery cannot be realized. According to published peer-reviewed clinical trials on UTx, the graft failure rates in living and deceased donor UTx are 21% and 36%, respectively. Supposing all recipients who did not have graft failure underwent embryo transfer, live birth rates in living and deceased donor UTx procedures are almost 63% and 71%, respectively. Currently, considering the occurrence of live births from both donations, particularly from nulliparous deceased donor, increased demand for UTx in the near future, shortage of uterus grafts, and lack of sufficient data for a comprehensive comparison between the 2 types of donation, the use of both donations still seems necessary and rational.

Early Uterine Transplant Graft Loss Due to Thrombosis: Single-Center Experience With Causes, Prevention, Diagnosis, and Treatment

Uterus transplantation (UTx) is a promising treatment option for women who wish to give birth but suffer from absolute uterine factor infertility. This paper presents an interim analysis of a trial focusing on the causes, prevention, diagnosis, and management of graft thrombosis. Our team analyzed 10 cases of UTx (recipients numbered 1 to 10). Early thrombosis developed in 2 of 10 (20 %) recipients, and thrombectomy and temporary viability preservation were achieved in both cases. However, re-thrombosis developed in both cases, and a graft hysterectomy was carried out. In recipient number 2, vascular changes might have contributed to graft thrombosis. The histopathological finding of the explant revealed subintimal excentric fibrosis with focal sclerotic changes. In recipient number 8, thrombosis was facilitated by external compression of the vascular pedicles by the hematoma as well as production of de novo donor-specific antibodies. Thrombosis led to graft loss in both cases despite an attempt at a thrombectomy. Therefore, the focus must be on the prevention including a thorough evaluation of the donor candidate. In the postoperative course, perfusion is closely followed-up with an ultrasound, Doppler flow monitoring, and macroscopic evaluation of the cervix. In the case that findings are unclear, a relaparotomy should be promptly indicated. If thrombosis is revealed, a thrombectomy and an attempt to salvage of the graft are indicated; however, the role of this strategy is questionable due to the low chance of long-term success. The indication of upfront graft removal and early re-transplantation in the treatment of uterine graft remains debatable.

Contralateral and Ipsilateral Arterial Vasculature of the Human Uterus: The Pilot Results of an Anatomical Study

Arterial blood to the human uterus is provided by a pair of uterine arteries (UA) and supported by terminal branches of ovarian (OA) and vaginal arteries (VA). Literature reports the existence of ipsilateral and contralateral anastomoses between these arteries and the UA, but data on the prevalence of such anastomoses are discrepant. The aim of this trial is to study whether contralateral and ipsilateral anastomoses exist. We studied nine human uterine specimens, which were obtained from (i) human cadavers (n = 6), (ii) uterine transplant recipients (n = 2), and (iii) one altruistic uterine donor (n = 1). We injected India ink into the graft through the UA of each specimen (n = 8) or OA (n = 1). We semiquantitatively observed and evaluated the extent of the injection on horizontal, vertical, and transmural levels. The dye permeated beyond the midline in 9/9 (100 %) cases. Near-complete/complete permeation to the contralateral side was observed in 6/9 (66 %) cases. The dye permeated ipsilaterally throughout all uterine levels in 8/8 cases (100 %) of UA injection. The entire wall of the myometrium was permeated in 2/9 (22 %) cases. In 7/9 (78 %) cases, the wall of the myometrium was permeated less than halfway through. In conclusions, the preliminary results of this study prove the existence of ipsilateral and contralateral anastomoses. Complete transmural injection was observed in only 22 % of cases; however, this finding does not provide information about the functional capacity of these anastomoses. More data and studies are necessary to make definitive conclusions.

A multi-institutional study of renal outcomes and renal-related pregnancy outcomes in uterus transplant recipients

Uterus transplantation (UTx) is an effective treatment option for uterine factor infertility. However, the need for immunosuppression and congenital renal anomalies that coexist with uterine agenesis in about 30% of women with Mayer-Rokitansky-Kuster-Hauser syndrome create a risk for renal dysfunction. We therefore examined renal function trajectory and related pregnancy complications in an international cohort of 18 UTx recipients from September 2016-February 2020 who had at least one live birth. All UTx recipients had a diminution in their renal function that was apparent starting at 30 days posttransplant and in half the reduction in eGFR was at least 20%; the decrease in eGFR persisted into the early post-partum period. Half met criteria for Stage 1 acute kidney injury (AKI) as defined by the AKI Network criteria during their pregnancy. Overall, 28% of UTx recipients developed pre-eclampsia. eGFR was lower at embryo transfer and throughout pregnancy among those who developed pre-eclampsia, reaching statistical significance at week 16 of pregnancy. This effect was independent of tacrolimus levels. Mean eGFR remained significantly lower in the first 1-3 months after delivery. In the subgroup who reached 12 months of postpartum follow up and had a graft hysterectomy (n = 4), there was no longer a statistical difference in eGFR (pretransplant 106.7 ml/m ± 17.7 vs. 12 mos postpartum 92.6 ml/m ± 21.7, p = .13) but the number was small. Further study is required to delineate long term renal risks for UTx recipients, improve patient selection, and make decisions regarding a second pregnancy.

Contralateral and Ipsilateral Arterial Vasculature of the Human Uterus: The Pilot Results of an Anatomical Study

Arterial blood to the human uterus is provided by a pair of uterine arteries (UA) and supported by terminal branches of ovarian (OA) and vaginal arteries (VA). Literature reports the existence of ipsilateral and contralateral anastomoses between these arteries and the UA, but data on the prevalence of such anastomoses are discrepant. The aim of this trial is to study whether contralateral and ipsilateral anastomoses exist. We studied nine human uterine specimens, which were obtained from (i) human cadavers (n = 6), (ii) uterine transplant recipients (n = 2), and (iii) one altruistic uterine donor (n = 1). We injected India ink into the graft through the UA of each specimen (n = 8) or OA (n = 1). We semiquantitatively observed and evaluated the extent of the injection on horizontal, vertical, and transmural levels. The dye permeated beyond the midline in 9/9 (100 %) cases. Near-complete/complete permeation to the contralateral side was observed in 6/9 (66 %) cases. The dye permeated ipsilaterally throughout all uterine levels in 8/8 cases (100 %) of UA injection. The entire wall of the myometrium was permeated in 2/9 (22 %) cases. In 7/9 (78 %) cases, the wall of the myometrium was permeated less than halfway through. In conclusion, the preliminary results of this study prove the existence of ipsilateral and contralateral anastomoses. Complete transmural injection was observed in only 22 % of cases; however, this finding does not provide information about the functional capacity of these anastomoses. More data and studies are necessary to make definitive conclusions.

Early Uterine Transplant Graft Loss Due to Thrombosis: Single-Center Experience With Causes, Prevention, Diagnosis, and Treatment

Uterus transplantation (UTx) is a promising treatment option for women who wish to give birth but suffer from absolute uterine factor infertility. This paper presents an interim analysis of a trial focusing on the causes, prevention, diagnosis, and management of graft thrombosis. Our team analyzed 10 cases of UTx (recipients numbered 1 to 10). Early thrombosis developed in 2 of 10 (20 %) recipients, and thrombectomy and temporary viability preservation were achieved in both cases. However, re-thrombosis developed in both cases, and a graft hysterectomy was carried out. In recipient number 2, vascular changes might have contributed to graft thrombosis. The histopathological finding of the explant revealed subintimal excentric fibrosis with focal sclerotic changes. In recipient number 8, thrombosis was facilitated by external compression of the vascular pedicles by the hematoma as well as production of de novo donor-specific antibodies. Thrombosis led to graft loss in both cases despite an attempt at a thrombectomy. Therefore, the focus must be on prevention including a thorough evaluation of the donor candidate. In the postoperative course, perfusion is closely followed-up with an ultrasound, Doppler flow monitoring, and macroscopic evaluation of the cervix. In the event that findings are unclear, a relaparotomy should be promptly indicated. If thrombosis is revealed, a thrombectomy and an attempt to salvage the graft are indicated; however, the role of this strategy is questionable due to the low chance of long-term success. The indication of upfront graft removal and early re-transplantation in the treatment of uterine graft remains debatable.

Transgender Males as Potential Donors for Uterus Transplantation: A Survey

Uterus transplantation is a new treatment for patients with absolute uterine infertility that is conducted in order to enable them to carry their own pregnancy. One of the limitations for its development is donor availability. Some transgender males undergo a hysterectomy in the gender-affirming surgery process, and might be interested in donating their uterus for transplantation. In this manuscript, we report the results of a survey designed to determine the attitudes of such individuals regarding donation of their uterus for this purpose. Over 32 years (January 1989-January 2021), 348 biological women underwent hysterectomy at our hospital as part of gender-affirming surgery. The survey was sent to 212 of the 348 prospective participants (for 136, we lacked postal or email addresses). Among the 212 surveys sent, we obtained responses from 94 individuals (44%): 83 (88.3%) stated they would agree to donate, of whom 44 would do so for altruism, 23 for the usefulness of the gesture and 16 out of understanding of the desire to have a child; 63 (75.5%) wanted to know the recipient and 45 (54.2%) wanted to know the result of the donation. According to this survey, a high proportion of transgender males surveyed would be interested in donating their uterus for uterus transplantation.

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.

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.

Strategic Planning and Essential Steps for Establishing a Uterine Transplant and Rehabilitation Program: From Idea to Reality

UTx is performed to address absolute uterine infertility in the presence of uterine agenesis, a nonfunctional uterus, or after a prior hysterectomy. After the initial success of UTx resulting in a livebirth (2014) in Sweden, there are over 70 reported UTx surgeries resulting in more than 40 livebirths worldwide. Currently, UTx has been performed in over 10 countries. As UTx is transitioning from an "experimental procedure" to a clinical option, an increasing number of centers may contemplate a UTx program. This article discusses essential steps for establishment of a successful UTx program. These principles may be implemented in cis- and transgender UTx candidates.

Immunologic and Infectious Concerns in Uterus Transplantation

Pharmacologic immunosuppression is required for the success of uterus transplantation but can provoke several complications for the transplant recipient. In this review, we discuss the immunologic complications that can occur in the uterus transplant recipient. First, we provide the latest update on immunosuppression regimens used by programs throughout the world. Next, we discuss the prevalence, mechanisms, treatment, and outcome of rejection in uterus transplant recipients. Finally, we discuss infectious complications of varying severity alongside their treatment and impact.

Risk constellations, viral infections, and prophylaxis in uterine transplantation

PURPOSE OF REVIEW

Uterine transplantation (UTx) is a burgeoning new category of solid organ transplantation (SOT) that is practiced at several centers worldwide (first transplantation in 2013). Although there are still relatively low numbers of transplants (<75 published in literature), they are increasing in frequency and thus we attempt to discuss the current documented infections in this population as well as theoretical infectious risks and summarize prophylaxis and treatment strategies of centers current performing these procedures.

RECENT FINDINGS

The most reported posttransplantation infection is not surprisingly urinary tract infections, with other documented infections including bacterial infections at site of graft (Enterococcus), herpes simplex virus, cytomegalovirus (CMV), human papillomavirus, Candida, and reportedly posttransplant lymphoproliferative disorder. The net state of immunosuppression and host factors (host colonization and serologic status of viral exposures) plays a significant role in infectious risk and with low numbers of infections documented, much of our guidance surrounding prophylaxis is inferred from SOT literature.

SUMMARY

In this review, we give an overview of described infections in UTx and theoretical infectious risks, detailing how to tailor prophylaxis base on host risk, with specific focus that the goal of transplantation is completion of a successful pregnancy as the desired outcome. Special considerations should be given to pregnant recipients when managing infectious complications and further data collection and reporting regarding infectious complications is crucial to advance this field as numbers of transplantation continue to increase.

Immunosuppression after uterus transplantation

PURPOSE OF REVIEW

Clinical uterus transplantation (UTx) is growing rapidly. The procedure represents the only therapy for women with absolute uterine factor infertility to give birth to a biological baby. Immunosuppression after UTx needs to carefully balance effects with the healthy mother and baby. Unique for UTx is the 'temporary' character of the procedure with a transplant hysterectomy being performed after delivery. Most of the practice on immunosuppression in UTx is currently based on the experience in solid organ transplantation (SOT).

RECENT FINDINGS

Clinical UTx-trials have been performed in centers worldwide during the recent years and experience on immunosuppression has accumulated.

SUMMARY

Immunosuppression in UTx has been successfully applied as maintenance treatment in addition to effectively treating acute T- and B-cell mediated rejections. Understanding the biology of UTx in more detail is expected to refine future approaches.

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 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.