Premium
Cell‐free DNA screening in twin pregnancies: A more accurate and reliable screening tool
Author(s) -
Chibuk Jason,
Rafalko Jill,
Boomer Theresa,
McCullough Ron,
McLennan Graham,
Wyatt Philip,
Almasri Eyad
Publication year - 2020
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.5797
Subject(s) - cell free fetal dna , medicine , trisomy , aneuploidy , obstetrics , twin pregnancy , population , prenatal diagnosis , cohort , pregnancy , gestation , gynecology , fetus , biology , genetics , chromosome , environmental health , gene
Abstract Objective Outcome data from cell‐free DNA (cfDNA) screening in twin gestations are limited. This study adds an appreciable number of confirmed outcomes to the literature, and assesses performance of cfDNA screening in twins over a 4.5‐year period at one large clinical laboratory. Method Prenatal cytogenetic and SNP microarray results were cross‐referenced with cfDNA results for twin pregnancies, yielding 422 matched cases. Using diagnostic results as truth, performance of cfDNA screening in this population was assessed. Results Of the 422 twin pregnancies with both cfDNA and diagnostic results, 3 specimens failed amniocyte analysis, and 48 samples (11.5%) were nonreportable from the initial cfDNA draw. Analysis of the 371 reportable samples demonstrated a collective sensitivity of 98.7% and specificity of 93.2% for trisomies 21/18/13. Positive predictive values (PPVs) in this study population, which is enriched for aneuploidy, were 78.7%, 84.6%, and 66.7% for trisomy 21, 18, and 13, respectively. Conclusion CfDNA screening in a cohort of twin pregnancies with matched diagnostic results showed superior performance compared to traditional serum biochemical screening in twins. This study adds to a growing body of evidence suggesting that cfDNA is an accurate and reliable screening tool for the major trisomies in twin pregnancies.