In vitro maturation improves oocyte or embryo cryopreservation outcome in breast cancer patients undergoing ovarian stimulation for fertility preservation

Abstract

This study tested in-vitro maturation (IVM) as a complementary strategy to improve the mature oocyte yield of breast cancer patients undergoing ovarian stimulation for fertility preservation. Secondary analysis of prospectively collected data is performed for 32 breast cancer patients undergoing oocyte or embryo cryopreservation before chemotherapy. Total number of oocytes and/or embryos cryopreserved following IVM is compared with the total number cryopreserved before IVM. Overall, 464 oocytes were retrieved, of which 274 were mature. Following IVM, the number of total mature oocytes increased to 399 (45% increase in mature oocyte yield, P<0.0001). Fertilization rate after IVM was statistically significantly higher than the fertilization of already mature oocytes at retrieval (86% versus 73%, respectively, P<0.05). The total number of oocytes and embryos frozen before IVM was 207 (45% of all oocytes retrieved). This number increased to 320 (69% of all oocytes retrieved) following IVM (P<0.0001). IVM is a useful strategy to improve the mature oocyte yield of fertility preservation cycles. Immature oocytes retrieved during oocyte/embryo cryopreservation cycles should not be discarded to improve the future potential of fertility.

Combined strategy for fertility preservation in an oncologic patient: vitrification of in vitro matured oocytes and ovarian tissue freezing

“…Smitz et al report implantation rates 2-3 times lower in embryos coming from IVM oocytes when compared to embryos coming from in vivo matured oocytes, early miscarriage rates also being higher in the first group [10]. On the other hand, in a recently published study, Oktay suggests IVM as an additional strategy in all fertility preservation cycles, even if ovarian stimulation is carried out, as it results in a 45% increase in mature oocyte yield [11].…”

Embryo Cryopreservation in Breast Cancer Patients

“…Implantation rates are lower than those expected with standard IVF, and this often necessitates the transfer of a larger number of embryos, which may increase the risk of multiple pregnancies. On the other hand, since a small percentage of oocytes retrieved during IVF are immature and typically discarded, these immature oocytes could be subjected to IVM to increase the oocyte and embryo yield in fertility preservation cycles [38].…”

Fertility after breast cancer treatment

“…It is reasonable to assume that the preservation of future fertility is likely to be a priority for women desiring pregnancy under the age of 40 years. Therefore, there are currently several potential options for women facing premature ovarian failure and desiring preservation of fertility, including all available assisted technologies, such as in-vitro fertilization and embryo transfer (IVF-ET), in vitro maturation, oocyte and embryo cryopreservation, and cryopreservation of ovarian tissue [16,[43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60].…”

“…In clinical situations for which chemotherapy needs to be started for young patients facing premature ovarian failure, ovarian tissue preservation seems to be a promissing option of restoring fertility, in conjuction with other options, like immature oocyte retrieval, in-vitro maturation of oocytes, oocyte vitrification, or embryo cryopreservation. It seems that in-vitro maturation is a useful strategy because it improves oocyte or cryopreservation outcome in breast cancer patients undergoing ovarian stimulation for fertility preservation [55]. Fertility preservation for breast-cancer patients using in-vitro maturation followed by oocyte or embryo vitrification calculated through pregnancy rates per vitrified oocyte and embryo were 3.8% and 8.1%, respectively [56].…”