Single Day 2 embryo versus blastocyst-stage transfer: a prospective study integrating fresh and frozen embryo transfers

Abstract

The observed cumulative delivery rates in this study do not allow us to take a position in favor of SBT or eSET. An improvement in blastocyst cryopreservation may change this attitude.

Clinical outcomes of elective single morula embryo transfer versus elective single blastocyst embryo transfer in IVF-ET

“…Similarly, most eSET have been mainly performed on day 2, 3, or 5. These studies have shown that the clinical pregnancy and delivery rates were significantly higher after eSBET compared to eSCET in selected patients [11][12][13]. The present retrospective study comparing eSMET to eSBET showed that the clinical pregnancy and live birth rates after eSMET were similar to those after eSBET in women with favorable conditions.…”

“…Da Costa et al [33] reported that the number of monozygotic twin pregnancies was increased by blastocyst transfer compared to cleavage stage ET due to more damage and hardening of the zona pellucida from an in vitro culture environment. Guerif et al [11] reported that the monozygotic twin birth rate was slightly higher in the eSBET group than the eSCET group (3.8% vs. 1.6%), but there was no statistical significance. However, Papanikolaou et al [34] showed that the number of monozygotic twin pregnancies was not increased after eSBET compared to eSCET.…”

“…In contrast to these results, it has been reported that the clinical outcomes of elective single blastocyst embryo transfer (eSBET) are similar to those of double blastocyst embryo transfer (DBET) on day 5 [10]. Also, some studies have shown that eSBET results in significantly higher pregnancy and delivery rates compared to day 2 or 3 elective single cleavage embryo transfer (eSCET) in selected groups [11][12][13]. In light of the above studies, eSBET can be one method that can decrease multiple pregnancy rates while maintaining an acceptable pregnancy rate.…”

The role of morphological evaluation of oocyte and embryo quality in ART programs (a review)

“…Если веретено поляризовано, то это может приводить к формированию эмбриона с неравными по размеру бластомерами. Аномальный цитокинез может приводить к патологической бла-стуляции, выражающейся в различиях размеров кле-ток во внутренней клеточной массе (inner cell mass, ICM) более чем на 30%, дефектам дальнейшего раз-вития [10,22,35,36]. На четырехклеточной стадии один из четырех бластомеров продолжает свое раз-витие в клетки, продуцирующие хорионический го-надотропин (ХГ), что является сигналом для эндоме-трия и подготовки к имплантации [10].…”

The actors of human implantation: gametes, embryo and endometrium

“…These usual morphological criteria are judged not sufficient for selecting the ideal embryo able to develop until the blastocyst stage and to transfer and to cryopreserve Guerif et al, 2009). Identification of non-invasive test of oocyte competence would undoubtedly improve the efficiency of assisted reproductive technology in selecting competent embryos.…”