Transplantation of the uterus

Most women with uterine factor infertility have today no prospect of carrying a pregnancy to term. The development of a method for transplantation of the human uterus would be a means for many of these women to become both genetic and gestational mothers. In this article we review the literature concerning the history and recent development in the area of uterine transplantation. We describe our newly developed model for heterotopic uterine transplantation in the mouse, which we are using for studies of pregnancy outcome and rejection mechanisms. We also address some of the specific questions that need to be solved before attempts to transplant the human uterus should be performed.     

Uterus transplantation: how far away from human trials?

Uterus transplantation is being developed as a possible future method to treat uterus factor infertility. This commentary gives an overview of the animal research that has been conducted in preparation for human uterus transplantation. In addition, requirements for further specific research activities within the field are identified. It is our prediction that uterus transplantation will be introduced as an experimental procedure in the human within a few years.     

Transplantation of the uterus in sheep: methodology and early reperfusion events

AIM: Uterine transplantation is developing into a clinical treatment for uterine factor infertility. An animal model with a similar uterus size and vessels to humans and with pregnancy extending over several months would be beneficial for research on uterine transplantation. The aim of this study was to develop and evaluate autotransplantation of the sheep uterus to an orthotopic position in the pelvis. METHODS: Female sheep (n=7) were subjected to laparotomy with the uterus and its vascular supply and drainage being surgically isolated. The excised uterus was kept ex vivo at +4 degrees C for 60 min and then autotransplanted with vascular end-to-side anastomoses to the external iliac vessels. The effects of uterine blood-reperfusion were assessed by measurements of pCO(2), pO(2), lactate and pH in uterine venous blood. Uterine contractility and histology was assessed after 3 h of reperfusion. RESULTS: Reperfusion of blood was observed in five out of seven transplanted uteri. The pCO(2)/pO(2)-ratio and the lactate level were initially elevated but decreased and became normal after 60 min. After 3 h of reperfusion there was a visible tissue blood flow and spontaneous uterine contractions were seen. Histological analysis revealed a mild inflammation, but no edema or stasis. CONCLUSIONS: This study demonstrates that the sheep uterus can successfully be autotransplanted to an orthotopic position with novel vascular connections. This model is suitable for future experiments studying long-term results concerning uterine viability and pregnancy using a transplanted uterus of similar size to the human uterus.     

Uterus transplantation: where do we stand today and where should we go?

If transplantation of the uterus is developed into a safe method with a reasonable chance for the patient to carry an uneventful pregnancy, this procedure could become a feasible fertility treatment for women with absolute uterus factor infertility. The activity in this research field is growing and during the past 5 years several reports have been published. In this brief review the authors summarize the state of research in this field and also speculate on what might lie ahead.     

Pregnancy in transplanted mouse uterus after long-term cold ischaemic preservation

BACKGROUND: The aim of this study was to evaluate the viability of the transplanted murine uterus after cold ischaemic preservation. METHODS: Uteri of mice (6-8 weeks old) were isolated and kept at 4 degrees C in vitro for 24 or 48 h in 0.154 mol/l NaCl or University of Wisconsin (UW) solution. Viability was evaluated by assessment of morphology and contractility in vitro. Furthermore, uteri were transplanted by vascular anastomoses to syngeneic recipients after 24 or 48 h cold ischaemic preservation in UW solution and morphology, blood flow and capacity to implant transferred blastocysts were assessed 2 weeks later. RESULTS: Uteri that had been preserved for 24 h exhibited normal morphology but after 48 h preservation minimal degenerative changes were seen. Spontaneous contractions occurred in uteri after 24 h as well as 48 h cold ischaemic preservation and prostaglandin F(2alpha)-stimulated responses were preserved. Blood flow and morphology were normal 2 weeks after transplantation in uteri preserved for 24 h, while grafts preserved for 48 h had a decreased blood flow and morphology showed total necrosis of the transplants. Transplanted uteri that had been preserved for 24 h developed pregnancies (in five out of six animals) after embryo transfer, with offspring showing normal weight and growth trajectory. CONCLUSIONS: This study shows for the first time that the mouse uterus tolerates cold ischaemic preservation and that pregnancies can be carried in transplanted uteri that have been preserved for 24 h.     

Uterine transplantation

Uterine factor infertility is either due to congenital malformation or acquired. Most women with uterine factor infertility have no chance to become genetic mothers, except by the use of gestational surrogacy. The logical but radical approach for treatment would be replacement of the unfunctional or absent uterus. Uterine transplantation could allow these women to become both genetic and gestational mothers. The present work reviews the existing literature on the history and recent development around this topic. We also briefly describe a newly developed model for heterotopic uterine transplantation in the mouse, in which pregnancies have been accomplished. Some specific issues that are required to be solved prior any further attempts to transplant the uterus in humans are also addressed.     

Rejection of the transplanted uterus is suppressed by cyclosporine A in a semi-allogeneic mouse model

BACKGROUND: A mouse uterus transplantation model has previously been developed for studies of various aspects of uterine transplantation, which in the future may be used as treatment for uterine infertility. The aim of the study was to evaluate the effect of the immunosuppressant cyclosporine A (CyA) on the rejection of the allotransplanted uterus in the mouse. METHODS: C57BL/6 mice were recipients of uteri from F1 hybrids (C57BL/6 x CBA/ca). Transplanted mice received vehicle (control, n=5), 10 or 20 mg/kg/day of CyA (CyA10, n=5 and CyA20, n=5). Untreated F1 hybrids with syngeneic transplants (n=3) were negative controls. On day 10 post-transplantation, the grafted uteri were examined, and biopsies were taken for histology and quantification of T cells. RESULTS: Histology analysis revealed necrosis of the uterine transplants in controls and to a lesser extent in the CyA groups. Apoptosis and inflammation was prominent in grafts from the CyA10 group but suppressed in the CyA20 group. A similar increase of CD4+ cells was seen in all groups, whereas the number of CD8+ cells was higher (P < 0.05) in the two allogeneic groups receiving CyA compared with the allogeneic vehicle group. CONCLUSIONS: CyA treatment clearly delays the progress of rejection of grafted uteri but is insufficient to suppress T cell infiltration. Interestingly, the number of CD8+ cells was higher in groups receiving CyA, possibly reflecting a CyA-dependent depression of activation-induced cell death (AICD) of cytotoxic T cells.