Ovarian tissue transplantations in 196 women by FertiPROTEKT- live birth rate of 26.5% per woman is associated with female age and first versus repeated transplantation

Abstract Study question What is the live birth rate of ovarian tissue transplantation and which factors are associated with the success rate? Summary answer Live birth rate per transplanted woman is 26.5% and the success rate is associated with female age and first versus repeated transplantation. What is known already Live birth rates after tissue transplantations have been reported to be between around 24% and 41% per patient. Success rates seem to be negatively associated with increasing female age at the time of tissue cryopreservation and with pelvic radiation. Success rates are apparently not reduced after overnight transportation of tissue before freezing. Study design, size, duration Registry analysis of 244 transplantations in 196 women, performed by 26 centers of the FertiPROTEKT network from 2007 to 2019 with a follow up till 12/2020. Participants/materials, setting, methods Orthotopic transplantation was performed in 196 women, 191 with previous malignant and 5 with previous non-malignant diseases. Size of transplanting centers varied between 1 and 100 transplantations per center (average: 9.5 ± 19.6 transplantations). Factors possibly associated with success rate such as female age, first and repeated transplantation, experience of the transplanting center and overnight transportation of the tissue before freezing were analysed. Main results and the role of chance Average age of all transplanted 196 women was 31.3 years (SD, standard deviation, 5.2) at the time of cryopreservation (range 17-44y) and 35.9 years (SD 4.8, range 23-47) at the time of first transplantation. Overall pregnancy rate was 30.6% (95% CI, 24.2-37.6%) per first transplantation and 32.7% (95% CI, 26.1-39.7) per patient. Overall live birth rate per first transplantation was 25.0% (95% CI, 19.1-31.7%) and per patient 26.5% (95% CI, 20.5-33.3%). Pregnancy and live birth rates were calculated and graphically expressed as a continuous function of age to allow estimation of success rates per age group. Success rate decreased with increasing age at the time of tissue freezing. Pregnancy rate after first transplantation was 34.5% (95% CI, 26.7-42.9%) in women <35y and 20.4% (95% CI, 10.6-33.5%) in women ≥35y. Pregnancy rate was higher after 1st transplantation (30.6% (95% CI, 24.2-37.6%)) compared to 2nd and more transplantations (11.8% (95% CI, 3.3-27.5%)). Pregnancy rates after 1st transplantation was higher in centers with ≥10 transplantations (35.1%) compared to centers with <10 transplantation (25.4%) (p = 0.12). Corresponding live birth rates were 27.0% and 18.6%. Success rates was not different in women with and without overnight transportation of tissue before cryopreservation. Limitations, reasons for caution The data were drawn from a registry analysis. Data such as ovarian reserve and premature ovarian insufficiency were not available for all women. Data might be influenced by different follow up policies of the centers. Wider implications of the findings The study reveals the high potential of ovarian tissue freezing and transplantation but only if freezing is performed in younger women. The study suggests to better focus on the first and not on repeated transplantations. It also opens the discussion if transplantation should rather be performed by experienced centres. Trial registration number Non