Aim: Uterine transplantation (UTx) is a potential option for child‐bearing in women with uterine infertility. Recovery of uterine function after allogeneic UTx in non‐human primates has not been reported. The objective of this study is to establish the functional uterine transplant model in non‐human primates.Methods: Uteri of two cynomolgus monkeys were simultaneously removed, cooled at 4°C and perfused with heparin saline. The uteri were interchanged with each other and then orthotopically transplanted. Immunosuppressive protocols included use of three agents (tacrolimus, mycophenolate mofetil and methylprednisolone) in case 1 and two agents (tacrolimus and methylprednisolone) in case 2. Transabdominal ultrasonography, vaginoscopy and biopsy of the transplanted uterine cervix were routinely conducted to monitor rejection after surgery.Results: The blood concentration of tacrolimus decreased 11 days after surgery and evidence of rejection was found in biopsy of the uterine cervix in both cases. The suspected rejection disappeared 23 days after surgery in case 1 and temporary menstruation resumed at 3 months after surgery. In case 2, blood flow to the uterine artery gradually decreased and the uterus resulted in atrophy due to ischemia, which has been triggered by rejection.Conclusion: Allogeneic UTx in the cynomolgus monkeys resulted in temporary recovery of menstruation with three immunosuppressants and uterine atrophy with two immunosuppressants. This preliminary experience suggests that recovery of uterine function after allogeneic UTx in non‐human primates is possible but more experiments are required.

Uterus transplantation (UTx) is a potential option for women with uterine factor infertility to have a child, but there has been no large-scale survey of the views on UTx in women of reproductive age in Japan. The present study was aimed to clarify the views of Japanese women of reproductive age on UTx for uterine factor infertility. A questionnaire on UTx was conducted by an Internet research company in December 2014 as a cross-sectional study in 3,892 randomly chosen women aged 25 to 39 years old. Responses were analyzed from 3,098 subjects (mean age 32.1±4.2 years old), after exclusion of inappropriate respondents in screening. Of the respondents, 62.1%, 34.7% and 18.1% favored adoption, UTx and gestational surrogacy, respectively. In contrast, 7.0%, 21.9% and 63.3% opposed adoption, UTx and gestational surrogacy, respectively. In choices of candidates for UTx based on highest priority, deceased persons (33.8%) and mothers (19.0%) were favored as donors, and women with congenital absence of the uterus (54.4%) and hysterectomy due to a malignant uterine tumor (20.0%) as recipients. Regarding societal acceptance of UTx, the answer rates were 15.7% for "UTx should be permitted", 77.6% for "UTx should be permitted with discussion", and 6.7% for "UTx should not be permitted, even with discussion". Regarding personal opinions on UTx, 44.2% were in favor, 47.5% had no opinion, and 8.3% were against. Our results suggest that many Japanese women of reproductive age feel that UTx is socially and individually acceptable, but that concerns requiring further discussion remain among these women. There was also a tendency for UTx to be viewed more favorably than gestational surrogacy.

How long is the allowable warm ischemic time of the uterus and what morphological and biochemical changes are caused by uterine ischemia/reperfusion injury in cynomolgus macaques? Warm ischemia in the uterus of cynomolgus macaques is tolerated for up to 4 h and reperfusion after uterine ischemia caused no further morphological and biochemical changes. Uterus transplantation is a potential option for women with uterine factor infertility. The allowable warm ischemic time and ischemia/reperfusion injury of the uterus in humans and non-human primates is unknown. This experimental study included 18 female cynomolgus macaques with periodic menstruation. Animals were divided into six groups of three monkeys each: a control group and groups with uterine ischemia for 0.5, 1, 2, 4 and 8 h. Biopsies of uterine tissues were performed before blood flow blockage, after each blockage time, and after reperfusion for 3 h. Blood sampling was performed after each blockage time, and after reperfusion for 5, 15 and 30 min for measurement of biochemical data. Resumption of menstruation was monitored after the surgical procedure. Morphological, physiological and biochemical changes after ischemia and reperfusion were evaluated. Mild muscle degeneration and zonal degeneration were observed in all animals subjected to warm ischemia for 4 or 8 h, but there were no marked differences in the appearance of specimens immediately after ischemia and after reperfusion for 3 h in animals subjected to 4 or 8 h of warm ischemia. There were no significant changes in any biochemical parameters at any time point in each group. Periodical menstruation resumed in all animals with warm ischemia up to 4 h, but did not recover in animals with warm ischemia for 8 h with atrophic uteri. Warm ischemia in actual transplantation was not exactly mimicked in this study because uteri were not perfused, cooled, transplanted or reanastomosed with vessels. Results in non-human primates cannot always be extrapolated to humans. The findings suggest that the tolerable warm ischemia time in the uterus is expected to be longer than that in other vital organs. This study was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 26713050. None of the authors has a conflict of interest to declare.