Embryo culture in step single and sequential media: influence on morphology and implantation potential of blastocysts

Abstract

Purpose. To assess the impact of step single and sequential culture media on the morphology and frequency of blastocyst implantation. Materials and methods. In total, 514 embryos obtained from patients aged 30 to 35 years and fertilized by ICSI were studied (2017 to 2018). The pool of embryos from each woman was randomly divided into two groups: the first group was cultured in the sequential media and the second - in the single ones. Evaluation of the effect was carried out by comparing the obtained blastocysts quality cultured in the single and sequential media. Blastocyst morphology was assessed using the modified Gardner D. K. scale. Statistical analysis was performed by Mann–Whitney U-test and Pearson's chi-squared test with Yates' correction. Statistically significant differences between the compared groups were considered at P < 0.05. Results. The studies found that the use of single Origio ® 1-Step medium at embryo culture phase improves the morphological quality of the resulting blastocyst compared to embryos cultured in sequential Origio ® Sequential Cleav™ / Sequential Blast™ media. No statistically significant difference in the pregnancy and implantation rate of blastocysts obtained after embryo cultivation in the step single or sequential media was detected. Conclusions. The priority in terms of obtaining a large number of high quality blastocysts with high implantation potential is to use a step single medium for the embryo cultivation.