BACKGROUND Fresh embryo transfer results in higher live birth rates, while thawed embryo transfer appears to result in healthier babies. This study aims to investigate the association between the transfer of fresh or thawed embryos at the cleavage or blastocyst stage and the perinatal outcomes. METHODS This analysis is a retrospective population-based study of 150 376 autologous embryo transf...

To find some prognostic factors for the outcome of frozen-thawed cycles, we have retrospectively analysed all frozen pre-embryos that were thawed during 1993 and 1994 at two in-vitro fertilization (IVF) units in Sweden. Supernumerary pre-embryos were frozen from 551 oocyte retrievals and these resulted in 660 frozen-thawed cycles which lead to 623 thawed embryo transfers. The outcome of these t...

Physical and chemical alterations caused by the freezing and thawing and their effects on survivals/developments in vitro were investigated. Of a total of 452 two-cell mouse embryos, the overall survival rate of the frozen-thawed embryos was 76.1% (344/452). The blastocyst formation of the frozen-thawed embryos was 32.6% (44/136) compared to 74.5% (117/157) in the fresh embryos (P<0.05). The to...

the effect of modified vitrification was assessed on cellular development capability in mouse embryos cultured in vitro. in this study, 466 embryos (from zygote to morula stages) were vitrified then thawed embryos have been incubated for in vitro farther development up to blastocyst stage. also, vitrification and thawing procedures were the same for all experimental groups. mouse different embr...

BACKGROUND To determine whether mouse embryos generated from frozen-thawed oocytes can successfully survive a second cryopreservation. METHODS Immature C57BL6*BALB/c female mice underwent superovulation and the collected oocytes were divided into three groups. Group A oocytes (n = 107) underwent IVF. Group B oocytes (n = 167) underwent IVF and embryos generated were then cryopreserved. Group ...

Problems during transport have been described in the l i t e ra tu re f o r human embryos desp i t e specifically-designed dry shippers, including failure of the dry shipper and poorer outcomes using the transported material. The aim of the present study was to examine the performance after thawing of embryos imported to the Hollywood Fertility Centre in a dry-shipper (MVE SC 4/2V). A total of ...

OBJECTIVE To achieve maximum post-thaw survival of frozen embryos. DESIGN Historical controlled study. SETTING Hospital-based fertility center. PATIENT(S) One hundred forty-five patients whose embryos were frozen and thawed according to the standard method, and 56 patients whose embryos were frozen and thawed according to a modified method. INTERVENTION(S) Modifications were made to the...

The objective of this study was to assess whether the exposure of zona pellucida-intact bovine embryos to the proteolytic enzyme, trypsin, during embryo washing has a detrimental effect on their subsequent survival and development. Embryos were collected nonsurgically from superovulated cows (n = 19) 7.5 d after insemination. Grade 1 and Grade 2 embryos were washed 12 times in modified Dulbecco...

Over a 26 month period 17% of couples having treatment in our clinical programmes selected a commercially available protein (normal serum albumin, NSA) prepared from pooled human sera instead of using their own serum as a supplement for their embryo culture media. In a retrospective analysis of >2000 gonadotrophin-stimulated cycles and 1000 cycles where frozen/thawed embryos were transferred, f...