Maturation in vitro of immature human oocytes for clinical use

Abstract

Human oocyte maturation is considered as the reinitiation and completion of the first meiotic division from the germinal vesicle stage (prophase I) to metaphase II, and the accompanying cytoplasmic maturation for fertilization and early embryonic development. Immature human oocytes obtained from patients undergoing gynaecological surgery, or ovulation induction or having polycystic ovary syndrome (PCOS) can be matured and fertilized in vitro. To date, 80% of immature oocytes matured to metaphase II when cultured in maturation medium supplemented with gonadotrophins and 85% of matured oocytes fertilized and cleaved in vitro. Following transfer of these embryos, pregnancies and live births have been achieved. However, the capacity for oocyte maturation was different when the immature oocytes were retrieved from PCOS patients and when the oocytes were cryopreserved at germinal vesicle stage.

Spontaneous in vitro maturation of oocytes prior to ovarian tissue cryopreservation in natural cycles of oncologic patients

“…The IVM rate achieved was low, but comparable to that reported by Cha and Chian (8.8 % to 34.5 %, [3]) and that published by Revel et al…”

Effect of Linolenic acid during in vitro maturation of ovine oocytes: embryonic developmental potential and mRNA abundances of genes involved in apoptosis

“…This includes re-initiation and completion of the first meiotic division and cytoplasmic maturation, which is critical for normal fertilization and further embryonic development [26]. In this regard, supplementation of maturation medium with ALA increased the synthesis of PGE2 by enhancing the total concentration of ω-6 fatty acids as precursors [3].…”

Differences in the transcriptional profiles of human cumulus cells isolated from MI and MII oocytes of patients with polycystic ovary syndrome

“…According to the different stages of meiosis, oocytes are at three different phases of nuclear maturation, which are as follows: germinal vesicle (GV), metaphase I (MI), and MII (Cha & Chian 1998, Marteil et al 2009. At the end of the nuclear maturation process, the oocyte that is arrested at MII following the extrusion of the first polar body (PB) is considered mature and able to be fertilized by the sperm.…”

“…The cross talk between an oocyte and the surrounding cumulus cells (CCs) is critical for achieving oocyte competence, early embryonic development and CC expansion (Salustri et al 1989, Cha & Chian 1998, Goud et al 1998. Previous researches have proved that different gene expressions of CCs could indicate oocyte competence or predict the efficiency of embryo development and pregnancy outcome (McKenzie et al 2004, Zhang et al 2005, Feuerstein et al 2007, Assou et al 2008, van Montfoort et al 2008, Kenigsberg et al 2009, Adriaenssens et al 2010, Assou et al 2010.…”