Blastomere movement post first cell division correlates with embryonic compaction and subsequent blastocyst formation

Abstract

Background Blastomere movement (BMov) occurs after the first cell division in human embryos. This movement has been suggested as a prognostic parameter for pregnancy outcome prediction following cleavage-stage embryo transfer. However, the effect of BMov on preimplantation development and pregnancy outcome after blastocyst transfer remains unclear. Therefore, this study aimed to evaluate whether BMov after the first cell division is correlated with blastocyst formation rate and live birth rate after single vitrified-warmed blastocyst transfer (SVBT). Methods Nine hundred and sixty-six embryos cultured in the EmbryoScope+® time-lapse system were retrospectively analyzed. The BMov type was categorized into three groups; namely, bouncing, wobbling, and twist-and-crumble. The BMov duration (dBMov) between the first (t2) and second cell division (t3) was monitored, and the ratio of dBMov to the duration of the 2-cell stage was calculated [dBMov/(t3-t2)]. Developmental rates to the 4-cell, 8-cell, morula, blastocyst, and expanded blastocyst stages were assessed, as well as blastocyst morphological grade. The correlations between dBMov and clinical pregnancy, ongoing pregnancy, and live birth rates were evaluated. Results Increased dBMov/(t3-t2) was significantly correlated with decreased developmental rates to the 8-cell, morula, blastocyst, and expanded blastocyst stages, especially from the 4-cell stage to the morula stage. Analysis of different types of BMov revealed that embryos with bouncing movement exhibited significantly higher developmental rates to the 8-cell, morula, blastocyst, and expanded blastocyst stages compared with embryos with twist-and-crumble movement. The morphological quality of blastocyst-stage embryos with twist-and-crumble movement was significantly lower than that of embryos with bouncing and wobbling movements. The rates of clinical pregnancy, ongoing pregnancy, and live birth after SVBT were not correlated with BMov type or duration. Conclusions Embryonic compaction and subsequent blastocyst formation are adversely affected by twist-and-crumble movement and prolonged movement after the first cell division. Our results indicate that the preimplantation developmental competence of human embryos could be predicted by assessing BMov after the first cell division on day 1. Electronic supplementary material The online version of this article (10.1186/s12958-019-0488-5) contains supplementary material, which is available to authorized users.

Anti-Müllerian hormone is correlated with cumulative live birth in minimal ovarian stimulation with clomiphene citrate: a retrospective cohort study

“…The collected cumulus-oocyte complexes (COCs) were washed and transferred to human tubal fluid (HTF) medium (Kitazato Corporation) with paraffin oil at 37 °C (gas phase: 5% O 2 , 5% CO 2 , and 90% N 2 ) for culturing, until either conventional IVF (cIVF) was performed 3 h later, or in cases of intracytoplasmic sperm injection (ICSI), denudation was performed 4 h after oocyte retrieval [ 32 , 33 ]. For ICSI, cumulus cells were removed, and the denuded oocytes were cultured in HTF medium for 1 h before ICSI.…”

“…After the confirmation of second polar body extrusion at 5 h after insemination (day 0), the fertilized oocytes were individually cultured in medium drops (ONESTEP medium; Nakamedical, Inc., Tokyo, Japan) with paraffin oil. For patients undergoing ICSI, oocytes were immediately placed in ONESTEP medium after sperm injection [ 32 , 33 ]. All embryos were cultured at 37 °C (gas phase: 5% O 2 , 6% CO 2 , and 89% N 2 ).…”

“…Single fresh or vitrified-warmed embryo transfers were performed in natural cycles [33,[37][38][39]. Briefly, the transfers of cleavage stage embryos and blastocysts were performed on days 2-3 and day 5 after oocyte retrieval or with the confirmation of ovulation, respectively.…”

Effects of gonadotropin administration on clinical outcomes in clomiphene citrate‐based minimal stimulation cycle IVF

“…During the study period, single embryo transfers were performed exclusively. Fresh or vitrified‐warmed embryo transfers were performed in spontaneous natural or hormonal replacement cycles as previously described . Cleaved embryo and blastocyst transfers were performed on days 2‐3 and day 5 after oocyte retrieval or the confirmation of ovulation, respectively.…”

“…Fresh or vitrified-warmed embryo transfers were performed in spontaneous natural or hormonal replacement cycles as previously described. 6,12,14,15 Cleaved embryo and blastocyst transfers were performed on days 2-3 and day 5 after oocyte retrieval or the confirmation of ovulation, respectively. Dydrogesterone (30 mg/d) was routinely orally administered during the early luteal phase after the embryo transfer procedure.…”