New insights for human oocyte recovery during assisted reproductive technologies

• Grant number: 23/02473-5
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2023
• End date: October 31, 2025
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Rosana Maria dos Reis
• Grantee: Rosana Maria dos Reis
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Cristiana Libardi Miranda Furtado
• Associated research grant(s): 24/02106-5 - Oocyte in vitro maturation after controlled ovarian stimulation, AP.R
• Associated scholarship(s): 23/16542-9 - Oocyte recovery for in vitro maturation, BP.TT

Abstract

During procedures of assisted reproduction, several follicles are recruited and resume meiosis during controlled ovarian stimulation (COS). Nevertheless, some of them do not reach the stage of metaphase II (MII), being discarded. In these cases, the oocyte in vitro maturation (IVM) after COS may be an important strategy to recover the unmatured oocytes, especially in cases such as the polycystic ovary syndrome, poor ovarian reserve cases, fertility preservation when time is restricted to only one COS cycle and, when COS may be a risk factor due to physiologic conditions such as cancer and high risk of hyperstimulation syndrome development. In this context, this project aims to develop new insights of oocyte recovery after COS. To do this, immature oocytes will be in vitro matured using two different media, the CAPA-IVM and GH-IVM. The oocytes that reach MII stage will be evaluated regarding morphology, ooplasm appearance, first polar body extrusion, mitotic spindle formation, mitochondrial and chromatin activity. Besides that, the expression of important genes related to oocyte competence, maturation and early embryo development will be evaluated in the matured oocytes and, the IVM medium will be evaluated to proteomic characterization and identification of miRNAs released by oocyte during IVM. This project brings IVM as a strategy to improve oocyte recovery of patients undergoing fertility preservation during oncological treatments, besides to assist patients during infertility treatment and to improve the rate of viable oocytes available to in vitro fertilization. (AU)