Fetal Fraction and Noninvasive Prenatal Testing: What Clinicians Need to Know

Abstract

(Abstracted from Prenat Diagn 2020;40:155–163) Fetal fraction (FF) is defined as the percentage of total maternal plasma cell-free (cf) DNA that is derived from the fetoplacental unit (FF = fetal cfDNA/[fetal cfDNA + maternal cfDNA]). The measured FF is dependent on both biological factors and bioinformatics algorithms and is used in interpretation of DNA sequencing results in noninvasive prenatal testing (NIPT).