Enhanced First Trimester Screening for Trisomy 21 with Contingent Cell-Free Fetal DNA: A Comparative Performance and Cost Analysis

Abstract Objective To evaluate the impact of cell-free fetal DNA (cfDNA) test on the number of invasive tests carried out in a public hospital that does not include this test in its services. Methods This was a retrospective cohort study in singleton pregnancies with a high risk (>1:270) on the first-trimester screening for aneuploidies. The options of performing an invasive test or a cfDNA test were explained to all women, the latter being especially recommended to those with a 1:50–1:270 risk (Group 1). If the risk was >1:50 (Group 2), or nuchal translucency (NT) was >99th percentile or there were major malformations (Group 3), invasive test was recommended. Results A total of 755 of 14,398 (5.2%) cases had a high-risk first-trimester screening, of whom 46 cases were excluded due to incomplete follow-up. In the remaining 709 cases, the percentage of aneuploidies was 9.9% (70 cases) and 110 opted for a cfDNA test (15.5%). There were two true-positive results of cfDNA (one in Group 2 and another in Group 3). In Group 1, 67.4% [95% confidence interval (CI) 60.0%–72.1%, P < 0.01] fewer invasive procedures were performed in those who opted for a cfDNA test, without having false negatives. Conclusion Pregnant women with a 1:50–1:270 risk who opt for cfDNA save two out of three invasive tests, without affecting the aneuploidy detection rate.

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Two-stage first-trimester screening for trisomy 21 by ultrasound assessment and biochemical testing

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.7663 ◽

2010 ◽

Vol 36 (5) ◽

pp. 542-547 ◽

Cited By ~ 38

Author(s):

K. O. Kagan ◽

I. Staboulidou ◽

J. Cruz ◽

D. Wright ◽

K. H. Nicolaides

Keyword(s):

Trisomy 21 ◽

First Trimester ◽

First Trimester Screening ◽

Two Stage ◽

Trimester Screening ◽

Ultrasound Assessment ◽

Biochemical Testing

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Sequential Pathways of Testing After First-Trimester Screening for Trisomy 21

Obstetrics and Gynecology ◽

10.1097/01.aog.0000139832.79658.b9 ◽

2004 ◽

Vol 104 (4) ◽

pp. 661-666 ◽

Cited By ~ 61

Author(s):

Lawrence D. Platt ◽

Naomi Greene ◽

Anthony Johnson ◽

Julia Zachary ◽

Elizabeth Thom ◽

...

Keyword(s):

Trisomy 21 ◽

First Trimester ◽

First Trimester Screening ◽

Trimester Screening

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Prenatal screening for trisomy 21: a comparative performance and cost analysis of different screening strategies

BMC Pregnancy and Childbirth ◽

10.1186/s12884-020-03394-w ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Tianhua Huang ◽

Clare Gibbons ◽

Shamim Rashid ◽

Megan K. Priston ◽

H. Melanie Bedford ◽

...

Keyword(s):

Trisomy 21 ◽

Prenatal Screening ◽

Rolling Circle Amplification ◽

False Positive Rate ◽

Diagnostic Testing ◽

First Trimester ◽

Aneuploidy Screening ◽

Comparative Performance ◽

Cell Free Fetal Dna ◽

Cfdna Screening

Abstract Background Prenatal screening for chromosome aneuploidies have constantly been evolving, especially with the introduction of cell-free fetal DNA (cfDNA) screening in the most recent years. This study compares the performance, costs and timing of test results of three cfDNA screening implementation strategies: contingent, reflex and primary. Methods We modelled enhanced first trimester screening (eFTS) as the first-tier test in contingent or reflex strategies. cfDNA test was performed contingent on or reflex from eFTS results. A comparison was made between cfDNA screening using sequencing technology and Rolling Circle Amplification (RCA)/imaging solution. All model assumptions were based on results from previous publications or information from the Ontario prenatal screening population. Results At an eFTS risk cut-off of ≥1/1000, contingent and reflex cfDNA screening have the same detection rate (DR) (94%) for trisomy 21. Reflex cfDNA screening using RCA/Imaging solution provided the lowest false positive rate and cost. The number of women requiring genetic counselling and diagnostic testing was significantly reduced and women received their cfDNA screening result 9 days sooner compared with the contingent model. While primary cfDNA screening improved the trisomy 21 DR by 3–5%, it was more costly and more women required diagnostic testing. Conclusion Reflex cfDNA screening is the most cost-effective prenatal screening strategy. It can improve the efficiency of prenatal aneuploidy screening by reducing the number of patient visits and providing more timely results.

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