Fertility preservation for breast-cancer patients using IVM followed by oocyte or embryo vitrification

Unstimulated in-vitro maturation (IVM) cycles are considered for fertility preservation in breast cancer due to avoidance of ovarian stimulation and shortened time to oocyte retrieval. This study evaluated the efficacy of this approach in a retrospective cohort analysis of 66 patients with breast cancer. Immature oocytes were collected and matured in vitro and then either vitrified or fertilized and preserved as vitrified embryos. In group 1 (vitrified oocytes, n=35), the average number of oocytes retrieved was 11.4 ± 8.8, the maturation rate was 64.2% and an average of 7.9 ± 6.6 oocytes were vitrified per patient treated. The median duration from the first evaluation to oocyte retrieval was 8 days. In group 2 (vitrified embryos, n=31) the average number of oocytes retrieved was 9.7 ± 6.4, the maturation rate was 53.2% and an average of 5.8 ± 2.7 mature oocytes were available for fertilization/patient. The fertilization rate was 77.8%, resulting in 4.5 ± 2.7 vitrified embryos/patient. The median duration from the first evaluation to oocyte retrieval was 13 days. Calculated pregnancy rates per vitrified oocyte and embryo were 3.8% and 8.1%, respectively. IVM can be considered a useful option for fertility preservation in breast-cancer patients.