Neonatal Outcomes after Uterus Transplantation: Dallas Uterus Transplant Study

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.

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.

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.

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.

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.

The First 5 Years of Uterus Transplant in the US

Importance

Uterus transplant is a viable surgical treatment for women affected by absolute uterine-factor infertility, which affects 1 in 500 women.

Objective

To review transplant and birth outcomes of uterus transplant recipients in the US since the first case in 2016.

Design, Setting, and Participants

In this cohort study, 5 years of uterus transplant outcome data were collected from the 3 centers performing uterus transplants in the US: Baylor University Medical Center, Dallas, Texas; Cleveland Clinic, Cleveland, Ohio; and University of Pennsylvania, Philadelphia. A total of 33 women with absolute uterine-factor infertility who underwent uterus transplant between February 2016 and September 2021 were included.

Main Outcomes and Measures

Graft survival, live birth, and neonatal outcome.

Results

Of the 33 included uterus transplant recipients, 2 (6%) were Asian, 1 (3%) was Black, 1 (3%) was South Asian, and 29 (88%) were White; the mean (SD) age was 31 (4.7) years; and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 24 (3.6). Most uterus transplant recipients (31 of 33 [94%]) had a congenitally absent uterus (Mayer-Rokitansky-Küster-Hauser syndrome), and 21 of 33 (64%) received organs from living donors. Mean (range) follow-up was 36 (1-67) months. There was no donor or recipient mortality. One-year graft survival was 74% (23 of 31 recipients). Through October 2021, 19 of 33 recipients (58%) had delivered 21 live-born children. Among recipients with a viable graft at 1 year, the proportion with a live-born child was 83% (19 of 23). The median (range) gestational age at birth of neonates was 36 weeks 6 days (30 weeks, 1 day to 38 weeks), and the median (range) birth weight was 2860 (1310-3940) g (median [range], 58th [6th-98th] percentile). No congenital malformations were detected.

Conclusions and Relevance

Uterus transplant is a surgical therapy that enables women with uterine-factor infertility to successfully gestate and deliver children. Aggregate data from US centers demonstrate safety for the recipient, living donor, and child. These data may be used to counsel women with uterine-factor infertility on treatment options.