background: the cryopreservation of human oocyte would make a significant contribution to infertility treatment, such as using it for oocyte donation and for patients a bout to lose ovarian function due to surgery or chemotherapy. despite of using standard freezing straws and cryovials or even open pulled straws, only a few successful pregnancies have been arisen from cryopreserved human oocyte...

BACKGROUND The use of immature oocytes is limited to cases where these are the only available oocytes, and they are usually only microinjected with sperm after having undergone maturation in vitro. This study compares the outcome of injection of sperm into metaphase I oocytes immediately after their denudation (MI) performed 2 h after their retrieval, with the outcome of injection of sperm into...

BACKGROUND Somatic cell nuclear transfer (SCNT) involves the transfer of somatic cell nuclei into enucleated oocytes. Because human in vivo matured oocytes are scarcely available, we investigated whether in vitro matured (IVM) germinal vesicle (GV) oocytes could also support preimplantation development of human cloned embryos. METHODS Three groups were used for SCNT: in vitro matured GV oocyt...

background: the high fertilization failure after ivf treatment cycles could be related to chromosomal abnormalities. this study was carried out to assess the frequency of chromosomal abnormality on human oocytes lacking signs of fertilization 18-20 h after insemination . materials and methods: on day one, 18-20 h after insemination (ivf), fertilization was confirmed when two pronuclei (normal i...

background: the present study has been carried out to investigate the effects of preovulatory stage gamma-irradiation of female mice in the absence or presence of vitamin e on numerical chromosome abnormalities in 8-cell embryos after mating with non-irradiated males. materials and methods: the 8-11 weeks adult female nmri mice were whole body irradiated at preovulatory stage (post pmsg injecti...

background: it is important to protect oocytes and embryos from oxidative stress in the culture medium. melatonin has been shown to be a direct free radical scavenger. objective: effect of melatonin during in vitro oocyte maturation, fertilization and embryo development of mouse oocytes was evaluated. materials and methods: oocytes from supper-ovulated mouse were divided to two groups: cumulus ...

Background: Vitrification of oocytes is a fast-freezing technique, which may affect the quality of the human oocyte, and consequently affects the embryo development, pregnancy and birth. The aim of the current study was to investigate the consequence of in-vitro vitrification on maturation status of immature human oocytes, additionally, expression levels of stress, and apoptosis related genes. ...

Background: In vitro maturation (IVM) of immature oocyte is a promising treatment option for infertile women.IVM procedures attempt to mimic the natural conditions of the follicular environment. The technique of IVM of oocytes has been successful after the first trial using culture of human oocytes in follicular fluid. The crucial part of this technique is the maturation process itself, and the...

Effective protocols are introduced for parthenogenesis activation in oocytes. Hydrostatic pressure can act as a mechanical stimulator that rearranges egg contents, leading to new structural or molecular combination. Alternatively, mechanical stimulation could stimulate a mechanically-gated process, such as opening or closing of stretch activated ion channels. This study, investigated the use of...