NIPT of Maternal Plasma-Originated cfDNA: Applications and Guide for the Implementation

Fco Javier Fernández Martínez,1 M Mar Gil Mira,2 Cristina González González,3 Irene Madrigal Bajo,4 Raluca Oancea Ionescu,5 Carmen Orellana Alonso,6 The group of experts agreed with the AEDP (Spanish Association of Prenatal Diagnosis) and AEGH (Spanish Association of Human Genetics):Fco. Javier Fernández Martínez, M. Mar Gil Mira, Cristina González González, Irene Madrigal Bajo, Raluca Oancea Ionescu, Carmen Orellana Alonso On behalf of the group of experts agreed with the AEDP (Spanish Association of Prenatal Diagnosis) and AEGH (Spanish Association of Human Genetics)1Genetics Service, 12 de Octubre University Hospital, 12 de Octubre Hospital Research Institute (Imas12), Madrid, 28041, Spain; 2Department of Gynecology and Obstetrics, University Hospital of Torrejón, Madrid, 28850, Spain; 3Genetics, Infanta Sofia Hospital, Madrid, 28702, Spain; 4Biochemistry and Molecular Genetics Service, Hospital Clínic de Barcelona, Barcelona, 08036, Spain; 5Clinical Genetics Unit, Clinical Analysis Service, Institute of Laboratory Medicine, Hospital Clínico San Carlos, Madrid, 28040, Spain; 6Genetics Service, Hospital Universitari i Politècnic la Fe, València, 46026, Spain; Genetics Service. 12 de Octubre University Hospital. 12 de Octubre Hospital Research Institute (Imas12). Avda de Andalucía s/n. Madrid, 28041. Spain. Email: [email protected]; Department of Gynecology and Obstetrics. University Hospital of Torrejón. C. Mateo Inurria, Torrejón de Ardoz. Madrid, 28850. Spain. Email: [email protected]; Genetics. Infanta Sofia Hospital. Madrid, 28702. Spain. Avda. de Europa, 34. San Sebastián de los Reyes, Madrid, 28702. Email: [email protected]; Biochemistry and Molecular Genetics Service. Hospital Clínic de Barcelona. C/ Villarroel, 170. Barcelona, 08036. Email: [email protected]; Clinical Genetics Unit. Clinical Analysis Service. Institute of Laboratory Medicine. Hospital Clínico San Carlos. Calle del Prof Martín Lagos, S/N. Madrid, 28040. Email: [email protected]; Genetics Service. Hospital Universitari i Politècnic la Fe. Avinguda de Fernando Abril Martorell, 106. València, 46026. Email: [email protected]: Fco Javier Fernández Martínez, Genetics Department, 12 de Octubre University Hospital, Avda de Andalucía km 5,400, Madrid, 28041, Spain, Email [email protected]: The implementation of non-invasive prenatal testing (NIPT) in maternal plasma, based on cell-free DNA (cfDNA) analysis, has progressed over the last two decades and is now integrated into the Spanish National Health System. However, there remains significant heterogeneity in its indications, technical methodologies, and reporting standards, reflecting international variability. This guide, developed by experts from the Spanish Association of Prenatal Diagnosis (AEDP) and the Spanish Association of Human Genetics (AEGH), provides recommendations to standardize NIPT application. It addresses key aspects such as technical and analytical requirements, integration with invasive diagnostic methods, pre- and post-test genetic counseling, and legal considerations. Additionally, the guide discusses the detection of common aneuploidies, the limitations in identifying structural chromosomal abnormalities and rare variants, and the impact of biological and clinical factors on test performance. By establishing a minimum framework based on scientific evidence, this document aims to optimize NIPT implementation in a cost-effective manner, ensuring clinical validity and informed decision-making for both healthcare professionals and pregnant women.Keywords: prenatal diagnosis, non-invasive prenatal test, cell-free DNA, functional guide