BACKGROUND Both cleavage-stage and blastocyst-stage embryo transfer policies have advantages and drawbacks. The number of embryos transferred, however, is a crucial parameter that needs to be considered before attempting any comparison. METHODS An extensive literature search yielded initially 282 studies from which 8 randomized controlled trials met the inclusion criteria: (i) truly randomize...

STUDY QUESTION Does the quality of a single transferred embryo have an effect on the pregnancy outcome? SUMMARY ANSWER After adjusting for confounding maternal variables, poor embryo quality was not associated with adverse obstetric or perinatal outcome in this small pilot study. WHAT IS ALREADY KNOWN Embryo quality is a major predictor of the success of in vitro fertilization treatment and...

BACKGROUND We have previously shown that the medium used for culturing IVF embryos affects the birthweight of the resulting newborns. This observation with potentially far-reaching clinical consequences during later life, was made in singletons conceived during the first IVF treatment cycle after the transfer of fresh embryos. In the present study, we hypothesize that in vitro culture of embryo...

the main factors affecting pregnancy and implantation rates are uterine receptivity, embryo quality, and transfer efficiency. embryo transfer (et) is the last step of critically important procedure of in vitro fertilization (ivf) and probably the least successful step in assisted reproductive technology (art) treatment cascade; though simple in most of the cases, it may pose to be the most diff...

On a worldwide basis, more than 750,000 embryos are produced annually from superovulated donors and more than 450,000 embryos are produced using in vitro techniques. Superovulation and embryo collection are done as frequently as every 30 days. Cryopreservation and direct transfer of frozen-thawed embryos results in pregnancy rates near that of fresh embryos. Since the zona pellucida-intact in v...

The aim of this study was to analyze the incidence of stage of embryonic development, embryo quality and the time of transfer on pregnancy rate in embryo transfer program timed. We were worked a total of 23Holsteincowsasembryo donors, super-ovulated with gonadotropin of pregnant mare serum (PMSG) (2500 3000UI).69 cows were used as recipients of Holstein dairy heifers with an age of20 months and...

The aim of this study was to analyze the incidence of stage of embryonic development, embryo quality and the time of transfer on pregnancy rate in embryo transfer program timed. We were worked a total of 23Holsteincowsasembryo donors, super-ovulated with gonadotropin of pregnant mare serum (PMSG) (2500 3000UI).69 cows were used as recipients of Holstein dairy heifers with an age of20 months and...

the success of oocyte donation is influenced by multiple factors. we performed a retrospective analysis to evaluate prognostic factors in oocyte donation cycles. the main outcome measurements including recipient age, donor age, estradiol level in midcycle, the day of transfer and number of transferred embryos were not different in pregnant and non pregnant groups. endometrial pattern but not en...