Human embryos are selected for transfer using morphology at the cleaving and blastocyst stages. Zygote morphology has been related to implantation and pregnancy. The aim of this study was to relate pronuclear morphology to blastocyst development. Zygotes were scored according to distribution and size of nucleoli within each nucleus. Zygotes displaying equality between the nuclei had 49.5% blast...

OBJECTIVE The aim of this study was to explore the effects of the insemination method on the outcomes of elective blastocyst culture. METHODS We retrospectively analyzed the outcomes of elective blastocyst culture performed between January 2011 and December 2014. RESULTS There were 2,003 cycles of conventional in vitro fertilization (IVF) and 336 cycles of intracytoplasmic sperm injection (...

Background: Arresting in a certain step of development like two-cell stage could be one of the reasons of infertility. The aim of this study is evaluating the effects of ethanol and strontium on growth and development of two-cell arrested mouse embryos. Materials and Methods: The females were coupled with male following superovulation. Positive vaginal plug mice were killed 48 hours after hCG i...

The objective of this experiment was to test in vitro embryo production (IVP) as a tool to estimate fertility performance in zebu bulls using Bayesian inference statistics. Oocytes were matured and fertilized in vitro using sperm cells from three different Zebu bulls (V, T, and G). The three bulls presented similar results with regard to pronuclear formation and blastocyst formation rates. Howe...

Embryo implantation is a highly orchestrated process that involves blastocyst-uterine interactions. This process is confined to a defined interval during gestation referred to as the "window of embryo implantation receptivity". In mice this receptive period is controlled by ovarian estrogen and involves a coordination of blastocyst adhesion competence and uterine receptivity. Mechanisms coordin...

Co-culture of human embryos (n = 384 cycles) to the blastocyst stage using Vero cell monolayers was carried out between August 1995 and December 1997. A total of 2868 zygotes were co-cultured and 1027 embryos reached the blastocyst stage (blastocyst formation rate 35.8%). The blastocysts were frozen in 43.7% of patients. A mean of 1.8 blastocysts was transferred per patient and 95 pregnancies w...

It has been shown previously that the intact blastocyst of the mouse can regulate tumor formation and colony formation of murine embryonal carcinoma. This effect is consistent with the close histogenetic correspondence between embryonal carci noma and the inner cell mass of the blastocyst. The ability of inner cell mass, blastocele fluid, and inner and outer surfaces of trophectoderm to abrogat...

In order to evaluate the niche of extended embryo culture in an IVF programme, retrospective analysis of non-selected IVF patients, who underwent ovarian stimulation from April 1998 to June 1999 in a single private practice assisted reproductive technology centre, was performed. Embryos were cultured for 48 h in S1/G1.2 medium followed by 48 to 72 h of culture in S2/G2.2 to day 5 or day 6. Only...

A retrospective study of 5,982 embryos in 619 blastocyst-stage embryo transfer cycles revealed that detection of multinucleated blastomeres either on day 2 or 3 signifies a poor prognosis for blastocyst formation and that no good-quality blastocyst can be expected from an embryo with more than one multinucleated blastomere. Patients should be counseled regarding a poor prognosis when multiple e...