The investigators propose to perform a clinical randomized trial to evaluate the effect of a frozen-thawed embryo transfer and a fresh embryo transfer on pregnancy and implantation rates; with the added benefit of a blastocyst biopsy and whole chromosome analysis by Next Generation Sequencing (NGS).
(*) Hatching blastocysts as described by Gardner and Schoolcraft (1999):
Inclusion Criteria (pre-stimulation):
Exclusion Criteria (pre-stimulation):