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Clinical accuracy of abnormal cell‐free fetal DNA results for the sex chromosomes
Author(s) -
Scibetta Emily W.,
Gaw Stephanie L.,
Rao Rashmi R.,
Silverman Neil S.,
Han Christina S.,
Platt Lawrence D.
Publication year - 2017
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.5146
Subject(s) - cell free fetal dna , fetus , medicine , prenatal diagnosis , biology , genetics , obstetrics , pregnancy
Objective To investigate factors associated with abnormal cell‐free DNA (cfDNA) results for sex chromosomes (SCs). Study design This is a retrospective cohort study of abnormal cfDNA results for SC at a referral practice from March 2013 to July 2015. Cell‐free DNA results were abnormal if they were positive for SC aneuploidy (SCA), inconclusive, or discordant with ultrasound (US) findings. Primary outcome was concordance with karyotype or postnatal evaluation. Results Of 50 abnormal cfDNA results for SC, 31 patients (62%) were positive for SCA, 13 (26%) were inconclusive, and 6 (12%) were sex discordant on US. Of SCA results, 19 (61%) were reported as 45,X and 12 (39%) were SC trisomy. Abnormal karyotypes were confirmed in 8/23 (35%) of SC aneuploidy and 1/5 (20%) of inconclusive results. Abnormal SC cfDNA results were associated with in vitro fertilization ( P = .001) and twins ( P < .001). Sex discordance between cfDNA and US was associated with twin gestation ( P < .001). Conclusions In our cohort, abnormal SC cfDNA results were associated with in vitro fertilization and twins. Our results indicate cfDNA for sex prediction in twins of limited utility. Positive predictive value and sensitivity for SC determination were lower than previously reported.