Guidelines for standardized nomenclature and reporting in uterus transplantation: An opinion from the United States Uterus Transplant Consortium

Doppler Flow Indices and Prediction of Embryo Transfer Success and Pregnancy Outcome in Uterus Transplant Recipients

OBJECTIVE

 Doppler velocimetry of the uterine and umbilical arteries is used to predict preeclampsia and monitor fetal outcomes. There have been no reports of Doppler velocimetry indices in pregnancies conceived after uterus transplantation, which differ from traditional pregnancies because of different uterine vascular inflow and outflow and exposure to immunosuppressive agents. We sought to examine whether Doppler indices can be used to predict embryo transfer success after uterus transplantation and whether Doppler indices across pregnancy predict fetal growth restriction.

STUDY DESIGN

 This was a single-center cohort observational study of 14 uterus transplant recipients who underwent embryo transfer. Of these, 12 women successfully delivered 14 babies. Five Doppler investigations were performed within the cohort: (1) prepregnancy; (2) uterine artery assessment across pregnancy; (3) umbilical artery assessment across pregnancy; (4) successive pregnancies; and (5) fetal growth.

RESULTS

 Prepregnancy uterine artery Doppler indices did not correlate with successful implantation after embryo transfer. Uterine artery Doppler indices in uterus transplant recipients decreased across pregnancy as described in pregnancies without uterus transplantation. The umbilical artery systolic/diastolic velocity ratio was lower at all weeks of gestation after uterus transplantation compared with values described in pregnancies without uterus transplantation. In those women who delivered two successive babies after uterus transplant, umbilical artery Doppler indices were significantly lower during the second pregnancy. There was always forward flow throughout diastole in the umbilical arteries, and no babies experienced fetal growth restriction.

CONCLUSION

 In our study, uterus transplantation was not associated with abnormal blood flow indices in either the uterine or umbilical arteries. Although Doppler indices were not predictive of embryo transfer success, they supported the expectation that pregnancies after uterus transplantation at our center result in normally grown babies.

KEY POINTS

· Uterus transplantation is not associated with abnormal blood flow indices.. · Prepregnancy uterine artery Doppler indices did not correlate with successful embryo implantation.. · Doppler assessment supports the expectation of normal placentation, fetal growth, and healthy live births after uterus transplantation..

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.

Three-year follow-up results of two children born from a transplanted uterus

AIMS

To evaluate the 3-year follow-up results of two children delivered at our institution in 2019 from mothers with a transplanted uterus.

METHODS

Observational data on pregnancy outcomes, neonatal course, and growth trajectory in two children born to mothers after uterus transplantation, including 3-year follow-up and neurodevelopmental status assessed using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III).

RESULTS

Both children were born prematurely via uneventful caesarean sections, to mothers with Mayer-Rokitansky-Küster-Hauser syndrome and a transplanted uterus. An acute caesarean section was performed in one mother because of the onset of regular uterine contractions at 34 weeks and 6 days of pregnancy; in the other mother, an elective caesarean section was performed at 36 weeks and 2 days of gestation. The children were born healthy with no congenital malformations. They had an uneventful postnatal course and showed a normal growth trajectory during 3 years of follow-up. The Bayley-III neurodevelopmental scores of both children were within the normal ranges at ages 2 and 3 years.

CONCLUSION

Though pregnancy after uterus transplantation is associated with the risk of premature delivery, no abnormalities were observed in the neonatal course and 3-year follow-up results, including the neurodevelopmental status, of two children born prematurely to mothers with a transplanted uterus. This is the first report on neurodevelopmental outcomes in children born after uterus transplantation. More data on children born after this radical procedure of uterine factor infertility treatment are required to support our promising results.

Persistence Pays Off: Live Birth after Uterus Transplant, Overcoming Recurrent Pregnancy Loss with Cerclage Placement

Recipients of uterus transplantation have unique factors that may increase their risk of cervical insufficiency. This report describes a uterus transplant recipient with cervical insufficiency resulting in two second-trimester miscarriages. After McDonald cerclages (one that failed), she underwent an interval transabdominal cerclage and delivered a healthy term child in her third pregnancy. The longitudinal information of this case provides observations from which we can propose testable hypotheses that address venous outflow and inflammation. This case also suggests that there could be a role for prophylactic cerclage placement at the time of transplantation.

Imaging of Uterine Transplantation

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

Uterus Transplantation as a Surgical Innovation

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

Immunosuppression in uterus transplantation: from transplant to delivery

INTRODUCTION

Uterus transplantation introduces unique challenges regarding immunosuppression, including the effects of immunosuppressive drugs on the fetus and graft rejection during pregnancy. Although immunosuppressive regimens are based on protocols used after solid organ transplantation, in recipients of uterus grafts, the physician must consider therapy modifications based on the phase of the transplant, from the intra-operative period through to delivery.

AREAS COVERED

This review discusses the current immunosuppressive rationale in uterus transplantation, focusing on the therapy in each phase of the transplant. The authors present an overview of the already approved immunosuppressive medications for solid organ transplantation, their application in uterus transplant prior to pregnancy, during pregnancy and as rejection treatment.

EXPERT OPINION

Most medications used for uterus transplant are adopted from solid organ transplantation experience, especially kidney transplantation, and rejection is treated in standard fashion. Research is needed to clarify the drugs' effects on fetal and neonatal well-being and to develop new medications to achieve better tolerance. Early markers of uterus graft rejection need to be identified, and prior rejection episodes should no longer be a cause to remove the graft during delivery in a recipient who wants a further pregnancy.

Neonatal Outcomes after Uterus Transplantation: Dallas Uterus Transplant Study

OBJECTIVE

Limited data are available on the outcome of infants born after uterus transplantation. Our aim was to describe the hospital course and laboratory findings in the first 2 months of life of the 12 infants born in the Dallas UtErus Transplant Study (DUETS).

STUDY DESIGN

Based on the trial protocol, information about infants was collected in a prospective fashion, including infant demographics, hospital course, and laboratory values.

RESULTS

Twelve infants were delivered, all by cesarean section, from 11 mothers who had undergone uterus transplantation (one mother had two pregnancies and delivered two babies). All pregnancies were singleton. The mothers received immunosuppressive therapy, and one had a rejection episode that was detected during pregnancy. The rejection episode resolved after steroid treatment. The infants had a median gestational age of 36^6/7 weeks (range: 30^6/7-38^0/7 weeks) and median birth weight of 2,920 g (range: 1,770-3,470 g). The lowest Apgar's score at 5 minutes was 8. All infants were appropriate size for gestational age. Two infants presented with bandemia but negative blood cultures. At 2 months of age, all infants achieved the developmental and behavioral milestones outlined by the American Academy of Pediatrics.

CONCLUSION

The 12 infants born from mothers with uterus transplants had a neonatal course that reflected the gestational age at delivery. No baby was born with an identified malformation or organ dysfunction. Longer follow-up and a larger number of infants are needed to confirm these observations.

KEY POINTS

· Normal fetal development after uterus transplantation.. · No baby was born with malformations or showed any organ dysfunction.. · At 2 months, all infants achieved appropriate developmental and behavioral milestones..

Radiologic Evaluation of Uterine Vasculature of Uterus Transplant Living Donor Candidates: DUETS Classification

Uterus transplantation is a treatment solution for women suffering from absolute uterine factor infertility. As much as 19.5% of uterus-transplanted patients underwent urgent graft hysterectomy due to thrombosis/hypoperfusion. The necessity to identify candidates with high-quality uterine vasculature is paramount. We retrospectively evaluated and compared the imaging results with actual vascular findings from the back table. In this article, we present a novel radiologic grading scale (DUETS classification) for evaluating both uterine arteries and veins concerning their suitability for uterus procurement and transplantation. This classification defines several criteria for arteries (caliber, tapering, atherosclerosis, tortuosity, segment, take-off, and course) and veins (caliber, tapering, plethora, fenestrations, duplication/multiplicity, dominant route of venous drainage, radiologist’s confidence with imaging and assessment). In conclusion, magnetic resonance angiography can provide reliable information on uterine venous characteristics if performed consistently according to a well-established protocol and assessed by a dedicated radiologist. The caliber of uterine arteries seems to be inversely related to the time passed since the last delivery. We recommend that the radiologist comments on the reliability and confidence of the imaging study. It cannot be over-emphasized that the most crucial aspect of surgical imaging is the necessity of high-quality communication between a surgeon and a radiologist.

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.

OPTN/SRTR 2020 Annual Data Report: VCA

The first vascularized composite allograft (VCA) transplant in the United States was performed in 1998 in a 40-year-old man who received a laryn-geal transplant after experiencing severe trauma to the throat 20 years before. The following VCA was a hand transplant in 1999 in a 37-year-old man who lost his left hand 13 years before. Since then, the field of VCA transplantation has made significant strides. On July 3, 2014, the Or gan Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) oversight of VCA procurement and transplant in the United States went into effect. In the last decade, the number of candidates listed for and transplanted with VCA has increased. While patient demographic data, whether listed candidates or patients undergoing VCA transplant, is limited by sample size, the trend is a predominance toward a young/middle-aged, White population. Overall outcomes data have been promising, with the vast majority of VCA transplants resulting in functioning grafts.

Technological Advancements in Uterus Transplantation

Uterus transplantation is barely a decade old and in a young, evolving field it is hard to identify "technological advances" since it is, in of itself, a technological advance. Nonetheless, one can still identify advances in diagnostic imaging that have improved donor screening to avoid graft losses, highlight the adoption of robotic surgery to make the living donor uterus procurement more minimally invasive, and look to a future of biotechnology like perfusion pumps and bioengineering such as synthetic uterus to increase donor supply. Additional technologies are on the horizon and promise to shape the field further.

The Future of Uterus Transplantation: Cost, Regulations, and Outcomes

Uterus transplantation (UTx) has evolved rapidly since technical success was first demonstrated, and is now practiced worldwide, using both living and deceased donors. As UTx transitions from an experimental to widely available standard clinical procedure, new challenges and questions are becoming more urgent. These include issues of cost and coverage, the establishment of guidelines and registries to ensure quality of care and monitor outcomes, regulatory oversight (including for the allocation organs from deceased donors), and the extent to which indications for UTx should be expanded.

Uterus transplantation - donor and recipient work-up

PURPOSE OF REVIEW

Uterus transplantation (UTx) is transitioning from an experimental procedure to a clinical treatment for absolute uterine factor infertility (AUFI). Standardized protocols for the evaluation and selection of donors and recipients that maximize chances of success - a healthy live birth - are needed.

RECENT FINDINGS

To date, recipient eligibility has been limited to otherwise healthy women with AUFI who are of childbearing age and are good candidates for in-vitro fertilization (IVF). For donors (living or deceased), selection criteria vary, apart from basic requirements of blood-type compatibility and freedom from critical infectious diseases, but generally require a term birth and a uterus free from uterine pathologies. The stepwise evaluation process for candidate recipients and living donors moves through health screening (medical and psychosocial); initial selection committee review; IVF (recipients only); and final selection committee review. This eliminates candidates with poor chances of success before exposure to unnecessary risks.

SUMMARY

The currently stringent selection criteria for prospective recipients and donors will likely broaden, as UTx becomes more widely available. Continued research is needed to define the donor, recipient and uterine graft factors associated with successful outcomes, and to support the development of standardized selection criteria.

Implementing regulations and policies for uterus transplantation

PURPOSE OF REVIEW

Policy development for uterus transplantation (UTx) is in its infancy. Understanding current oversight of UTx programmes can inform further development.

RECENT FINDINGS

Currently, the United States has the most comprehensive regulations for UTx. Much of the policy outside the USA is focused on candidate selection. In the USA, UTx is categorized as, and follows policies of, a vascular composite allograft. Some considerations for UTx have not yet been addressed in policy, including the need for candidates to have a viable embryo before listing and transplantation, additional factors that may be warranted in organ allocation and the need to report data on the infant as well as the recipient.

SUMMARY

Oversight of UTx falls within the governance of solid organ transplantation with unique aspects to be considered. Guidelines for multidisciplinary care, transplant-focused infrastructure and defined outcome metrics found in other solid organ transplant programmes provide a useful framework for UTx programmes.

Uterus transplantation: state of the art in 2021

PURPOSE

To provide a comprehensive review of uterus transplantation in 2021, including a discussion of pregnancy outcomes of all reported births to date, the donor and recipient selection process, the organ procurement and transplant surgeries, reported complications, postoperative monitoring, preimplantation preparation, and ethical considerations.

METHODS

Literature review and expert commentary.

RESULTS

Reports of thirty-one live births following uterus transplantation have been published from both living and deceased donors. The proper selection of donors and recipients is a labor-intensive process that requires advanced planning. A multidisciplinary team is critical. Reported complications in the recipient include thrombosis, infection, vaginal stricture, antenatal complications, and graft failure. Graft rejection is a common occurrence but rarely leads to graft removal. While most embryo transfers are successful, recurrent implantation failures in uterus transplant patients have been reported. Rates of preterm delivery are high but appear to be declining; more data, including long-term outcome data, is needed.

CONCLUSIONS

Uterus transplantation is an emerging therapy for absolute uterine factor infertility, a condition previously without direct treatment options. It is paramount that reproductive health care providers are familiar with the uterus transplantation process as more patients seek and receive this treatment.

Uterus transplantation-questions and answers about the procedure that is expanding the field of solid organ transplantation

Uterus transplant is a new and rapidly evolving field of solid organ transplantation designed to help women with absolute uterine-factor infertility who desire to carry their own pregnancies. The advent of this procedure and human clinical trials of uterus transplantation have raised technical, clinical, and ethical questions. We address several questions about uterus transplantation based on available literature and the clinical experience at Baylor University Medical Center, which has the largest uterus transplant program in the United States.

Clinical pregnancy rates and experience with in vitro fertilization after uterus transplantation: Dallas Uterus Transplant Study

BACKGROUND

The clinical pregnancy rates among patients with uterus transplantation have been reported by only a limited number of centers, and those centers have not used preimplantation genetic testing for aneuploidy in their protocol.

OBJECTIVE

This study examined clinical pregnancy rates among women with absolute uterine-factor infertility undergoing in vitro fertilization using good-quality, expanded-blastocyst-stage, euploid embryos after uterus transplantation.

STUDY DESIGN

This cohort observational study involved 20 women who underwent uterus transplantation over 3 years. Notably, 14 of these patients had successful transplants and were followed prospectively for a median of 14.1 months (range, 11-34.8 months). In vitro fertilization was performed before subjects underwent uterus transplantation, and good-quality expanded-blastocyst-stage euploid embryos were obtained and frozen for future embryo transfer. Interventions consisted of in vitro fertilization, preimplantation genetic testing for aneuploidy, uterus transplantation, and frozen embryo transfer.

RESULTS

All 14 subjects with successful transplants underwent single embryo transfer of a warmed, good-quality, euploid, expanded blastocyst and had at least 1 documented clinical pregnancy within the uterus. In 71.4%, the first embryo transfer resulted in clinical pregnancy. The median time from successful uterus transplantation to first embryo transfer was 4.5 months; from successful uterus transplantation to first clinical pregnancy, 7.3 months; and from successful uterus transplantation to first live birth, 14.1 months. A total of 13 live births have occurred in 12 subjects.

CONCLUSION

Women with absolute uterine-factor infertility who have surgically successful uterus transplantation and in vitro fertilization using preimplantation genetic testing for aneuploidy can achieve high clinical pregnancy rates. We have reduced the time interval from uterus transplantation to embryo transfer by at least 50% and the interval from uterus transplantation to clinical pregnancy by >6 months compared with previous studies. We believe our approach may shorten the time from transplant to clinical pregnancy and therefore decrease patient exposure to immunosuppressant therapies.

Uterus transplantation: state of the art in 2021

PURPOSE

To provide a comprehensive review of uterus transplantation in 2021, including a discussion of pregnancy outcomes of all reported births to date, the donor and recipient selection process, the organ procurement and transplant surgeries, reported complications, postoperative monitoring, preimplantation preparation, and ethical considerations.

METHODS

Literature review and expert commentary.

RESULTS

Reports of thirty-one live births following uterus transplantation have been published from both living and deceased donors. The proper selection of donors and recipients is a labor-intensive process that requires advanced planning. A multidisciplinary team is critical. Reported complications in the recipient include thrombosis, infection, vaginal stricture, antenatal complications, and graft failure. Graft rejection is a common occurrence but rarely leads to graft removal. While most embryo transfers are successful, recurrent implantation failures in uterus transplant patients have been reported. Rates of preterm delivery are high but appear to be declining; more data, including long-term outcome data, is needed.

CONCLUSIONS

Uterus transplantation is an emerging therapy for absolute uterine factor infertility, a condition previously without direct treatment options. It is paramount that reproductive health care providers are familiar with the uterus transplantation process as more patients seek and receive this treatment.

The path toward ectogenesis: looking beyond the technical challenges

BACKGROUND

Breakthroughs in animal studies make the topic of human application of ectogenesis for medical and non-medical purposes more relevant than ever before. While current data do not yet demonstrate a reasonable expectation of clinical benefit soon, several groups are investigating the feasibility of artificial uteri for extracorporeal human gestation.

MAIN TEXT

This paper offers the first comprehensive and up to date discussion of the most important pros and cons of human ectogenesis in light of clinical application, along with an examination of crucial ethical (and legal) issues that continued research into, and the clinical translation of, ectogenesis gives rise to. The expected benefits include advancing prenatal medicine, improving neonatal intensive care, and providing a novel pathway towards biological parenthood. This comes with important future challenges. Prior to human application, important questions have to be considered concerning translational research, experimental use of human fetuses and appropriate safety testing. Key questions are identified regarding risks to ectogenesis' subjects, and the physical impact on the pregnant person when transfer from the uterus to the artificial womb is required. Critical issues concerning proportionality have to be considered, also in terms of equity of access, relative to the envisaged application of ectogenesis. The advent of ectogenesis also comes with crucial issues surrounding abortion, extended fetal viability and moral status of the fetus.

CONCLUSIONS

The development of human ectogenesis will have numerous implications for clinical practice. Prior to human testing, close consideration should be given to whether (and how) ectogenesis can be introduced as a continuation of existing neonatal care, with due attention to both safety risks to the fetus and pressures on pregnant persons to undergo experimental and/or invasive procedures. Equally important is the societal debate about the acceptable applications of ectogenesis and how access to these usages should be prioritized. It should be anticipated that clinical availability of ectogenesis, possibly first as a way to save extremely premature fetuses, may spark demand for non-medical purposes, like avoiding physical and social burdens of pregnancy.

Preimplantation genetic testing for aneuploidy in uterus transplant patients

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

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

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