eSET or eDET Associated to PGT in IVF

In vitro fertilization (IVF) techniques have been improving performance recently and, nowadays, provide a live birth rate of around 25%. The success of IVF techniques is dependent upon maximum efficiency at each stage of treatment, and, at the same time, high success rates with a low risk of complications. Multiple pregnancies are one of the most important adverse event of IVF techniques. In this sense, the use of elective single embryo transfer (SET) has become an option for patients with good prognosis compared to the transfer of multiple embryos, and it is recommended in order to reduce the risk of multiple pregnancies and their consequences. On the other hand, it is known that embryonic quality is a crucial step for the success of IVF techniques and the efficiency of this process is linked to the decrease in the number of embryos to be transferred. Usually, embryo selection is based on morphological and developmental criteria. However, recently, it has been demonstrated that the blastocyst biopsy associated with the chromosomal / genetic screening may be a predictor of the chances of implantation. The investigators group demonstrated the feasibility of performing SET sequentially, promoting satisfactory gestation rates and safety for the mother and baby regarding multiple gestation for patients with good prognosis. Based on these principles, the investigators raised the hypothesis that SET associated with preimplantation genetic diagnosis (PGD) by next-generation sequencing (NGS) for patients with good prognosis can improve the success rates of IVF cycles and, at the same time, avoid multiple pregnancies, as well as maternal-fetal and neonatal risks resulting from this condition. To test this hypothesis, the aim of this study is to compare the results of IVF treatments in patients receiving SET (SET group), SET associated with genetic evaluation by NGS (group NGS + SET), elective transference of two embryos (DET group) and DET associated with genetic evaluation