The relationship between good quality embryo rates and IVF outcomes/embryo transfer policies in extended embryo culture

This study aims to investigate which parameters affect the change in good quality embryo rates during the cleavage stage and whether they have any effect on embryo transfer policies and IVF results. We analysed changes in good quality embryo (grades 1 and 2) rates during the period on days 2, 3 and 5; patients with five or fewer embryos (group 1), 6-10 embryos (group 2) and more than 10 embryos (group 3). The good quality embryo rates decreased in all groups on day 5. When the infertility reasons are studied among all of the groups, ovulatory dysfunction is found to be significantly higher in group 2 compared to group 1 and unexplained infertility was found to be significantly higher in group 2 compared to group 1 and group 3. Total antral follicle, mature oocyte and total oocyte counts were found to be significantly lower in group 1. However, there is no significant difference found among all of the groups for β-HCG levels and clinical pregnancies. Changes in good quality embryo rates at the cleavage stage in extended embryo culture do not have an impact on IVF results.IMPACT STATEMENTWhat is already known on this subject? The number and quality of embryos in the cleavage stage are important parameters affecting the embryo transfer decision on day 5. There is still insufficient knowledge concerning changes in the percentage of increased good quality embryo transfers associated with IVF outcomes during the second to the third day, and the third to the fifth day.What do the results of this study add? Day 5 embryo transfer is possible in patients with a low number of embryos, according to our results. The good quality embryo rates of patients with a low number of embryos at the cleavage stage are more promising compared to patients having more than five embryos.What are the implications of these findings for clinical practice and/or further research? An extended embryo culture option can be used on patients with a low number of embryos for clinical practice.