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.Breast cancer represents about 30% of malignant tumours occurring in women of childbearing age. Approximately 10–15% of breast cancers are diagnosed in women of reproductive age. Over the past two decades, earlier diagnosis and highly effective systemic therapies have led to reductions in mortality. However, women undergoing treatment for breast cancer may suffer from fertility problems in the future. A number of methods are currently used to preserve fertility in young breast cancer patients including ovarian freezing, IVF and preservation of oocytes and embryos and the use of drugs to protect the ovary during chemotherapy. A newly described method, in-vitro maturation, was used in our study. Freezing the eggs of breast cancer patients using this technique was found to be a useful treatment option due to two advantages: (i) no hormones were used and (ii) short duration of treatment. Our study evaluates the efficacy of this treatment approach for patients suffering from breast cancer.