Since the first successful aggregation of mouse embryos was reported by TARKowsKi,ii) many studies on chimera production have been carried out.S'6'7) Chimeras produced by the aggregation of early embryos have been widely used in experimental investigations of mammalian embryolegy and developmental genetics.4'9) Chimeric experimental animals have also been used to study some problems of human ge...

Differential effects of 2 transfer models for normal thawed embryos of 1 donor doe were studied on the offspring rate and their embryo survival at birth from 3 selected rabbit strains (SY and SB: synthetic strains, NZ: New Zealand White). Morulae were obtained 64-66 h post-coitum from 93 adult does treated with 25 IU of hCG (SY:36, NZ:27, SB:30). Morphologically normal morulae were frozen in th...

BACKGROUND Frozen- thawed embryo transfer is an essential part of ART treatment and outcomes of this procedure are associated with several clinical factors. Several studies have showed an increase level of IVF outcomes in women with sufficient vitamin D. OBJECTIVE whether treatment of vitamin D insufficiency can improve pregnancy rates in frozen-thawed embryo transfer cycles. MATERIALS AND ...

BACKGROUND Obesity is associated with poor reproductive outcomes, but few reports have examined thawed embryo transfer in obese women. Many studies have shown that increased lipid accumulation aggravates vitrification injury in porcine and bovine embryos, but oocytes of these species have high lipid contents (63 ng and 161 ng, respectively). Almost nothing is known about lipids in human oocytes...

Controlled ovarian hyperstimulation (COH) affects adversely implantation following in vitro fertilization and embryo transfer. COH with gonadotropins alters endometrial receptivity and luteal function. In addition periovulatory endometrial characteristics in stimulated cycles are considerably different compared with the natural cycles, and periovulatory secretory transformation is consistently ...

This study aimed to assess the effects of embryonic developmental stage, quality grade, and fresh or frozen/thawed conditions on pregnancy rate sex ratio live offspring in Hanwoo (<italic>Bos taurus coreanae</italic>) cows. The stage <italic>in vivo</italic>-derived (IVD) transferred embryos were evaluated using standard criteria International Embryo Technology Society. ...

BACKGROUND A number of factors influence the success of oocyte cryopreservation and subsequent ICSI. The aim of the present study is to establish the ideal time, after oocyte retrieval, for human oocyte cryopreservation via slow freezing/rapid thawing protocol with 0.3 M sucrose concentration in cryoprotectant solution (SF/RT 0.3 M). METHODS Retrospective study with 75 patients on the clinica...

BACKGROUND The purpose of this study was to evaluate the respective influences of blastomere survival and resumption of mitosis on the outcome of frozen-thawed embryos. METHODS A retrospective analysis was performed in our centre on 363 thawing cycles, involving 4-cell day 2 grade 1 embryos with <10% fragmentation. RESULTS A higher implantation rate per transferred embryo was observed when ...

The effect of cryopreservation on the integrity and fertilizing capacity of round spermatids was studied in two azoospermic patients. In December 1995 the patients, both with maturation arrest of spermatogenesis, were submitted to testicular sperm extraction (TESE) after an extensive examination of their ejaculate. Only round spermatids were found after testicular biopsy. Some of the spermatids...

The aim of this study was to report a successful pregnancy using completely immotile frozen-thawed spermatozoa selected by laser. A single laser shot was used to detect the presence of viable immotile spermatozoa in fresh and frozen-thawed testicular spermatozoa. The viability rate was 55.8% after the laser detection, and cryopreservation was carried out immediately. The thawing test was perfor...