Human oocyte vitrification: in-vivo and in-vitro maturation outcomes

Abstract

This study aimed to evaluate oocyte vitrification efficiency using in-vivo matured (IVO) versus rescued in-vitro matured (IVM) oocytes. The results show that oocyte survival (85% versus 81%), fertilization (86% versus 76%) and cleavage rate (98% versus 89%) was not significantly different in IVO oocytes compared with rescued IVM sibling oocytes. The fertilized oocytes from IVO and IVM groups were cultured to blastocyst stage; however, embryo development was significantly reduced in the rescued IVM group (72% versus 15%). Embryo transfer was only performed with the embryos derived from IVO oocytes on day 5; 42 blastocysts were transferred to 18 recipients; 16 of 18 recipients had positive beta-human chorionic gonadotrophin and a total of 26 fetal cardiac activities were detected in 15 recipients (implantation: 26/42, 61.9%). Ten of the 15 recipients have delivered 19 healthy babies, and the other five pregnancies are still ongoing. These data indicate that the combination of oocyte vitrification and rescued IVM not only yield a new strategy to extend the pool of total fertilizable oocytes, but also demonstrate that the efficiency of vitrified/warmed oocytes can be comparable to fresh oocytes with regard to clinical outcomes.

Vitrification vs. slow cooling protocol using embryos cryopreserved in the 5th or 6th day after oocyte retrieval and IVF outcomes.

“…In last few years this technique has received increasing interest among embryologist leads to significant development. It is used to freeze animal and human embryos at any stage of their development as well as germinal cells [7,[9][10][11][12][13][14][15][16][17].…”

The use of immature oocytes in the fertility preservation of cancer patients: current promises and challenges

“…However, the data remain preliminary, based solely on failed to mature denuded oocytes, with low maturation rates and no comparison non-cryopreserved oocytes in two of the transferred resulting in a singleton pregnancy and birth. A subsequent study in 2008 examined the utility of rescued IVM together with cryopreservation in an attempt to increase the pool of total fertilizable oocytes (Chang et al, 2008). From a total of 29 in vitro matured oocytes (that were failed to mature in vivo GV oocytes), 79% survived, 48% fertilized, 41% cleaved, and 7% developed to blastocyst.…”

“…From a total of 29 in vitro matured oocytes (that were failed to mature in vivo GV oocytes), 79% survived, 48% fertilized, 41% cleaved, and 7% developed to blastocyst. Together with cryopreservation, rescued IVM can thus provide an additional pool of fertilizable oocytes, although developmental competency is compromised when compared to the vitrification of in vivo matured oocytes (with 53% blastocyst formation) (Chang et al, 2008).…”

“…If M-I oocytes are retrieved, cryopreservation may be performed at the M-I or M-II stage following IVM. To date, results indicate that oocytes deemed M-I at retrieval yield improved outcomes when compared to GV oocytes (Chang et al, 2008;Fasano et al, 2010;Versieren et al, 2011;Zhang et al, 2011;Fasano et al, 2012). However, there isn't a direct clinical utility of retrieved M-I oocytes for cancer patients since GV oocytes would be obtained instead.…”

Vitrificación ovocitaria para posponer fecundidad: experiencia de la Unidad de Medicina Reproductiva de Clínica Monteblanco

“…Últimamente, se ha abierto otra posibilidad con la criopreservación de ovocitos (12,13). En los úl-timos años la criopreservación de ovocitos ha alcanzado resultados satisfactorios mediante la vitrificación de ellos, publicándose excelentes tasas de sobrevida, de fecundación y embarazo (14,15).…”