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UK NHS pilot study on cell-free DNA testing in screening for fetal trisomies: Factors affecting uptake

Research output: Contribution to specialist publicationArticle

Maria del Mar Gil, Giuliana Giunta, Elisa Macalli, Leona Poon, Kypros Nicolaides

Original languageEnglish
JournalUltrasound in Obstetrics and Gynecology
E-pub ahead of print2014

King's Authors


Objective: The study reports the clinical implementation of cell-free (cf)DNA testing, contingent on the results of the combined test, in screening for fetal trisomies 21, 18 and 13 in two UK NHS hospitals. Women with combined test risk of >1:100 (high-risk) are offered the options of chorionic villous sampling (CVS), cfDNA testing or no further testing and those with risk of 1:101-1:2500 (intermediate-risk) are offered cfDNA or no further testing. The objective of the study is to examine the factors affecting patient decisions concerning their options.

Methods: Combined screening was performed in 6,651 singleton pregnancies and the risk for trisomies was high in 260 (3.9%), intermediate in 2,017 (30.3%) and low in 4,374 (65.8%). Logistic regression analysis was used to determine which factors amongst maternal characteristics, fetal nuchal translucency (NT) and risk for trisomies were significant predictors of opting for CVS in the high-risk group and opting for cfDNA testing in the intermediate-risk group.

Results: In the high-risk group, 104 (40.0%) women opted for CVS; predictors for CVS were increasing fetal NT and risk for trisomies and predictor against CVS was Afro-Caribbean racial origin (R=0.366). In the intermediate-risk group, 1,850 (91.7%) opted for cfDNA testing; predictors for cfDNA testing were increasing maternal age, increasing risk for trisomies and university education and predictors against cfDNA testing were Afro-Caribbean racial origin, smoking and parity (R=0.105).

Conclusions: The study has identified factors that influence the decision of women undergoing combined screening in favor or against CVS and in favor or against cfDNA testing.

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