Outcomes of random-start letrozole protocol with PGT-A in women with breast cancer undergoing fertility preservation.

PURPOSE  : To compare the cycle characteristics and outcomes of random-start-controlled ovarian stimulation (RSCOS) protocols to the outcomes of standard-start-controlled ovarian stimulation (SSCOS) cycles and to report the utility of PGT-A in these cycles. METHODS: One hundred and seventeen who underwent SSCOS and 39 who underwent RSCOS for oocyte and/or embryo cryopreservation before breast cancer chemotherapy were retrospectively evaluated. Mean number of embryos and blastocyst euploidy rates were the main outcome measures. RESULTS: A majority of RSCOS cycles were initiated in the luteal phase (66.6% luteal vs. 33.3% follicular). While the total dose of gonadotropins was significantly higher in the RSCOS (3720.8 ± 1230.0 vs. 2345.1 ± 803.6 IU; P < 0.001), the mean number of mature oocytes and embryos was similar to SSCOS. However, there was a trend for a higher number of mean embryos with luteal start RSCOS (6.9 ± 2.7 in late follicular start vs. 9.4 ± 4.2 in luteal start, P = 0.08). PGT-A was performed in 48% of the cases that underwent embryo cryopreservation in RSCOS (12 women, mean age = 35.3 ± 4.1; 87 blastocysts), revealing a euploidy rate of 36.2 ± 22.3% per patient. This rate was comparable to a 45% aneuploidy rate from similarly aged published data. Of the 7 RSCOS patients who returned for frozen embryo transfer, 5 delivered and one has an ongoing pregnancy, while in SSCOS, 18 out of 40 cycles resulted in live birth. CONCLUSION: Our data suggests that RSCOS fertility preservation cycle outcomes are similar to those with SSCOS and result in age-appropriate euploidy rates.