Detecting Androgenetic Origin of the Genome via Single-Nucleotide Polymorphism-Based Cell-Free DNA Screening in Dichorionic Diamniotic Twin Pregnancies With Complete Hydatidiform Moles and a Coexisting Normal Fetus: A Three-Case Report.

What is already known about this topic? ◦. Complete hydatidiform mole with a coexisting normal fetus (CHMCF) refers to a pregnancy in which a normal fetus and a complete mole coexist. ◦. CHMCF is associated with substantial maternal and fetal morbidity, including hemorrhage, severe anemia, hypertensive disorders, hyperthyroidism, prematurity, fetal loss, and an increased risk of gestational trophoblastic neoplasia. What does this study add? ◦. We report three cases of dichorionic diamniotic (DCDA) twin pregnancies with suspected CHMCF, in which single‐nucleotide polymorphism (SNP)–based cell‐free DNA (cfDNA) analysis detected the androgenetic origin of the genome implying concurrent presence of paternal uniparental diploidy and biparental diploidy in maternal plasma. ◦. To our knowledge, this is among the first case series applying SNP‐based cfDNA prospectively in this specific clinical scenario in twin pregnancy. Its prospective dual‐component detection in twins has a potential clinical decision impact on CHMCF.