Frozen-Thawed Embryo Transfer Using Autologous Oocytes Retrieved from Women Aged ≥ 45 Years: A Retrospective Study

Objective: To assess the pregnancy outcomes, including live birth rate and pregnancy loss for women aged 45–49 years at the time of oocyte retrieval, who underwent frozen autologous transfer of embryos. Methods: Among frozen-thawed embryo transfers (ET) performed at our clinic from September 2013 to March 2021, 1,114 cycles of women aged 45–49 years at the time of oocyte retrieval were examined retrospectively. Positive pregnancy test, clinical pregnancy, pregnancy loss, and live birth rates per transfer among each age group were analyzed using one-way analysis of variance or the Fisher’s exact test. Results: The mean age at the time of oocyte retrieval and ET was 45.8 and 46.5 years, respectively. Positive pregnancy test rate was 7.6%, of which 72.9% resulted in pregnancy loss. The clinical pregnancy and live birth rates were 5.1% and 2.0%, respectively, with a live birth rate of 3.0% for women with oocytes retrieved at 45 years of age. Multivariate analysis revealed that younger oocyte retrieval age was associated with biochemical and clinical pregnancy; however, no such association was observed for cases with live birth. The oocyte retrieval age of patients with live births was 45 years in 16 cases, 46 years in six cases, and 47 years in one case. In one case of live birth (46 years old), 21 trisomy was observed in the child; however, congenital abnormalities were not observed in other cases. Chorionic tests were performed on the fetuses in 12 of the 33 clinical abortions, of which 11 showed chromosomal abnormalities. Conclusions: Fertility treatment with autologous oocytes in advanced-age women has a low success rate. Although prognosis is poor above 45 years of age, these results can help in providing information to aid patients in their decisions regarding whether or not to pursue treatment.