Is euploidy what embryos need for implantation and live birth? We also need quality

Abstract

Introduction To have an euploid embryo is one of the main biomarkers conditioning the outcome of an IVF cycle since the sole morphological appearance it is not always related to the euploidy status of the embryo. Blastocysts with a good morphology can be aneuploid and vice versa. In this study, the implantation potential and the live birth rate (LBR) of euploid warmed blastocyst after PGT was analyzed according to the quality of the biopsied blastocysts. Additionally, the age factor was also considered. We evaluated the association between the patient´s age and the euploidy status of the embryos. Materials and Methods We included retrospectively 976 warmed blastocysts from a total of 828cycles, since January 2016 to December 2017, from our PGT program (1504-VLC-027-MD). Indications for PGT-A were advanced maternal age (66.8%), repetitive implantation failure (12.7%), recurrent miscarriage (7.0%), severe male factor (12.7%), previous pregnancy with aneuploidy (2.5%) and mixed causes (2.3%).Thetrophectoderm biopsy was completed either on Day 5 or on Day 6 of embryo development according to the degree of expansion and quality reached by the blastocyst. The trophectoderm analysis was done by NGS, and one hour after biopsy blastocysts were vitrified. The day of the transfer, only euploid embryos were warmed, waited for a minimal of two hour for their re- expansion and then graded according the morphological ASEBIR classification (type A, B, C), based on both the degree of expansion and the quality of the trophectoderm. Implantation and LBR were analyzed according to the type of embryo with a Chi-squared test. Statistical significance was achieved for values of p 38 years. Implantation potential of transferred blastocysts was compared between both groups. Results Weobtained statistical significant differences in implantation potential (p Conclusions For euploid embryos, the grading of the blastocysts will determine the implantation potential and the chances of a live birth. These differences are of crucial importance for biopsied blastocysts on Day 6. Regarding the age of the patient, once we have euploid embryos, the patients ‘age is not a decisive parameter in terms of chances of embryo´s implanting.