Non-Invasive Preimplantation Genetic Testing (niPGT).

Selection of a normal euploid embryo for transfer is a crucial step in assisted reproduction treatment. While trophectoderm (TE) biopsy has been widely employed, the consequences of removing cells on embryo viability remain unknown. In contrast, non-invasive preimplantation genetic testing (niPGT) can determine an embryo's chromosomal content without the need to perform a biopsy. This strategy obtains valuable information by analyzing the genetic material released by the blastocyst into the culture medium, with high concordance with TE biopsies, inner cell mass biopsies, and the whole embryo. To achieve this, the culture medium sample must contain enough good-quality embryonic material, which can be influenced by sample collection timing. Further, minimizing the risk of contamination remains crucial, as contamination can result in misdiagnosis. For these reasons, performing niPGT in an IVF laboratory requires slight modifications to the standard embryo culture protocol. Here, we describe the protocol to maximise the probability of obtaining an informative and accurate niPGT result.