() Cohort III-2 5,267 Aim: To assess the implementation of CFDNA screening was performed in 5,267 Study population TESTING into clinical practice utilising both women and as a first-line screening method may not be first- and second-line screening models. in 3,359 (63.8%). Detection rates were 100% generalisable to for trisomies 21 and 13 and 88% for the Australian Setting: Metropolitan private practices in trisomy 18. Of cases with known karyotypes, obstetric Australia the positive predictive value (PPV) of the community as Population: Singleton pregnancies in a test was highest for trisomy 21 (97.7%) and women were mixed risk population lowest for monosomy X (25%). predominantly Methods: cfDNA testing was offered as a older, Ultrasound detection of structural first-line screen, ideally followed by Caucasian and anomaly resulted in the detection of five combined first-trimester screening (cFTS), or from higher additional chromosome anomalies, two of as a second-line test following cFTS, socioeconomic which had high-risk cFTS results. particularly in those with a calculated risk groups For all chromosomal anomalies, cfDNA between 1:50 and 1:1000. alone detected 93.4%, cfDNA in a Outcomes: Detection of trisomies 21, 18 13, model detected 81.8% and cFTS alone sex chromosome aneuploidies and other detected 65.9% (P < 0.005). anomalies If women had only had cFTS, the rate of invasive procedures would have been 5.5% higher (p<0.0001). Given the false-positive rate for all aneuploidies, cfDNA is an advanced screening test, rather than a diagnostic test. Retrospective cohort studies Trisomy 21 only Study ref Design LoE N Aim, setting, population, methods Results Comments
() Cohort III-2 5,267 Aim: To assess the implementation of CFDNA TESTING into clinical practice utilising both first- and second-line screening models. Setting: Metropolitan private practices in Australia Population: Singleton pregnancies in a mixed risk population Methods: cfDNA testing was offered as a first-line screen, ideally followed by combined first-trimester screening (cFTS), or as a second-line test following cFTS, particularly in those with a calculated risk between 1:50 and 1:1000. Outcomes: Detection of trisomies 21, 18 13, sex chromosome aneuploidies and other anomalies screening was performed in 5,267 women and as a first-line screening method in 3,359 (63.8%). Detection rates were 100% for trisomies 21 and 13 and 88% for trisomy 18. Of cases with known karyotypes, the positive predictive value (PPV) of the test was highest for trisomy 21 (97.7%) and lowest for monosomy X (25%). Ultrasound detection of structural anomaly resulted in the detection of five additional chromosome anomalies, two of which had high-risk cFTS results. For all chromosomal anomalies, cfDNA alone detected 93.4%, cfDNA in a model detected 81.8% and cFTS alone detected 65.9% (P < 0.005). If women had only had cFTS, the rate of invasive procedures would have been 5.5% higher (p<0.0001). Given the false-positive rate for all aneuploidies, cfDNA is an advanced screening test, rather than a diagnostic test. Study population may not be generalisable to the Australian obstetric community as women were predominantly older, Caucasian and from higher socioeconomic groups Retrospective cohort studies Trisomy 21 only Study ref Design LoE N Aim, setting, population, methods Results Comments
cfDNA%20testing%20evidence%20evaluation%2016May17.docx