Conceptus size on Day 14 after multiple embryo transfer of Day 7 in vitro-produced blastocysts varies greatly within animal. One explanation for this variation may be related to blastocyst cell number at the time of transfer. The aim of this study was to examine the effect of Day 7 blastocyst cell number on Day 14 conceptus size and to examine the effect of progesterone (P4) supplementation on ...

Previous studies have shown that heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) mRNA is synthesized in the mouse uterine luminal epithelium temporally, just prior to implantation, and spatially, only at the site of blastocyst apposition (Das, S. K., Wang, X. N., Paria, B. C., Damm, D., Abraham, J. A., Klagsbrun, M., Andrews, G. K. and Dey, S. K. (1994) Development 120...

Eighty per cent of rat blastocysts (Wistar, SW72) cultured for 96 h in NCTC-109 supplemented with fetal calf serum (FCS) hatched from the zona pellucida and developed a trophoblast giant cell lyer. Thirty seven per cent from the rat blastocysts developed an inner cell mass (ICM) which, in about 7% consisted of two germ layers (ectoderm and endoderm) compared to 84% in NMRI mice. A significantly...

horbar; Three experiments were undertaken to investigate the effect of some factors on survival and viability of bovine blastocysts produced in vitro in serum-free oviduct-conditioned media. In vitro survival to freezing was higher for blastocysts appearing on days 6 and 7 than for day 8 blastocysts (67 and 50% hatching rate vs 12%). Transfer success of day 8 blastocysts to recipient heifers wa...

Background: The efficiency of in vitro fertilization (IVF) is still low to be developed to blastocyst stage probably because of environmental conditions. It is likely that in vitro environment can not exactly mimic in vivo environment due to differences in media, metabolic content, atmospheric composition, temperature and pH. Therefore it may affect embryo quality by changing in embryo gene exp...

Uniparental disomy (UPD) has been shown to be rare in human normal blastocysts, but its frequency in discarded morphologically abnormal embryos and its relevance to embryonic self-correction of aneuploid remains unknown. The aim of this study was to detect UPD in discarded morphologically abnormal embryos. Both discarded morphologically abnormal embryos, including zero-pronuclear zygotes (0PN),...

Is the timing of vitrification after trophectoderm (TE) biopsy associated with successful implantation and pregnancy after the embryo transfer of blastocysts subjected to preimplantation genetic screening (PGS)? In this retrospective cohort study, 1329 blastocysts from 223 patients were subjected to TE biopsy for performing array comparative genomic hybridization (CGH) tests. The PGS and frozen...

BACKGROUND/AIM Obtaining human embryonic stem cell lines has so far involved destroying the embryos. This has given rise to ethical concerns and is not permitted in most countries. This investigation tested whether removing multiple cells from blastocysts might allow continued embryonic development. MATERIALS AND METHODS A total of 40 blastocysts from a black mouse strain were biopsied. The m...

Background: Due to the seasonality reproduction of albino hamster (April to October in the Northern Hemisphere) and the need to produce blastocysts for research applications, producing and collecting blastocysts by natural mating in non-breeding season is complex in this species. In the present study in vivo blastocysts production and collection using super-ovulation and intrauterine inseminati...

Although improved outcomes of IVF after transfer of blastocysts has been reported (1, 2), it remains uncertain which blastocyst can develop into a viable fetus. At present, expansion of the blastocyst is the most practical selection criterion. However, if extended culture of embryos produces many expanded-stage blastocysts, it is not easy to decide which blastocysts to transfer (Fig. 1A). In ad...