Earlier day of blastocyst development is predictive of embryonic euploidy across all ages: essential data for physician decision-making and counseling patients

Abstract

Purpose The purpose of this study is to evaluate whether day of blastocyst development is associated with embryo chromosomal status as determined by high-density oligonucleotide microarray comparative genomic hybridization (aCGH). Methods This is a retrospective cohort analysis, including women who underwent in vitro fertilization (IVF) with trophectoderm biopsy at a single private fertility center from January 2014 to December 2014. Repeat cycles were excluded. Cycles were assessed for percentage of blastocysts biopsied on days 5, 6, or 7 and rate of euploid embryos per cycle. Cycles were stratified by Society for Assisted Reproductive Technology (SART) age groups (< 35, 35-37, 38-40, 41-42, > 42) and by donor status. Results A total of 388 IVF cycles and 2132 biopsied blastocysts were evaluated. The percentages of blastocysts biopsied on days 5, 6, and 7 were 62.5, 35.8, and 1.7%, respectively. Blastocyst euploid rates on days 5, 6, and 7 were 49.5, 36.5, and 32.9%, respectively. Earlier blastocyst development was associated with a significantly increased euploid rate (p < 0.0001). Younger maternal age (p < 0.0001) and higher number of blastocysts biopsied per patient (p = 0.0063) were both independently associated with greater percentage of euploidy. Conclusions Earlier blastocyst development is independently associated with a higher likelihood of embryonic euploidy in both autologous and donor embryos. In non-biopsied embryos, these data support selection of day 5 blastocysts for transfer over later-developing embryos. These results can assist with patient counseling regarding expectations and outcomes. To our knowledge, this is the first study to examine embryonic euploidy as stratified by both day of blastocyst development and SART age group.

Is day 7 culture necessary for in vitro fertilization of cryopreserved/warmed human oocytes?

“…We also found that 3.5% of the oocyte warming cycles had only Day 7 blastocysts, which was the same as that with fresh oocyte IVF [9]. Day 7 blastocysts had poorer quality as compared with Day 5 or Day 6 blastocysts [9,11,12]. The similar results were also observed in the present study.…”

Pregnancy outcomes after day 5 versus day 6 blastocyst‐stage embryo transfer: A systematic review and meta‐analysis

“…Aneuploidy is a very common abnormality in human embryos, particularly in blastocysts with slow growth rate (reach the blastocyst stage at day 6). Recent researches have suggested that high aneuploidy rate in day 6 blastocysts was an important reason for the low development potential thus affecting the clinical pregnancy and implantation rates . In this regard, comprehensive chromosomal screening can be used, a technique that allows reproductive specialists to determine the situation of chromosomal aberrations of an embryo, offering unequivocal statements about reproductive potential of particular embryo .…”

“…Recent researches have suggested that high aneuploidy rate in day 6 blastocysts was an important reason for the low development potential thus affecting the clinical pregnancy and implantation rates. 20,33 In this regard, comprehensive chromosomal screening can be used, a technique that allows reproductive specialists to determine the situation of chromosomal aberrations of an embryo, offering unequivocal statements about reproductive potential of particular embryo. 34 In line with this, we observed that transfer of euploid day 5 blastocyst resulted in higher implantation and live birth rate than the transfer of euploid day 6 blastocyst, while there was no significant difference between day 5 and day 6 blastocyst transfers for clinical pregnancy and ongoing pregnancy rates.…”

Are cleavage anomalies, multinucleation, or specific cell cycle kinetics observed with time-lapse imaging predictive of embryo developmental capacity or ploidy?

“…Implantation and live-birth rates are lower with slow growing embryos not blastulating until the sixth day of culture (5)(6)(7). PGS data indicate lower euploidy rates with day 6 versus day 5 biopsied blastocysts (8,9). Sophisticated incubation chambers with continuous live imaging of embryos in culture have produced a wealth of new information and raised the intriguing possibility of using such data to refine blastocyst selection and/or deselection criteria.…”