Impact of Cell-Free Fetal DNA Screening on Patients’ Choice of Invasive Procedures after a Positive California Prenatal Screen Result

Abstract

Until recently, maternal serum analyte levels paired with sonographic fetal nuchal translucency measurement was the most accurate prenatal screen available for Trisomies 18 and 21, (91% and 94% detection and false positive rates of 0.31% and 4.5% respectively). Women with positive California Prenatal Screening Program (CPSP) results have the option of diagnostic testing to determine definitively if the fetus has a chromosomal abnormality. Cell-free fetal (cff-) DNA screening for Trisomies 13, 18, and 21 was first offered in 2012, allowing women with positive screens to choose additional screening before diagnostic testing. Cff-DNA sensitivity rates are as high as 99.9% and 99.1%, with false positive rates of 0.4% and 0.1%, for Trisomies 18 and 21, respectively. A retrospective chart review was performed in 2012 on 500 CPSP referrals at the University of California, San Diego Thornton Hospital. Data were collected prior to and after the introduction of cff-DNA. There was a significant increase in the number of participants who chose to pursue additional testing and a decrease in the number of invasive procedures performed after cff-DNA screening was available. We conclude that as fetal aneuploidy screening improves, the number of invasive procedures will continue to decrease.

The implementation and impact of non-invasive prenatal testing (NIPT) for Down’s syndrome into antenatal screening programmes: A systematic review and meta-analysis

“…Twenty-one manuscripts met the inclusion criteria for part A, reporting on 27 countries, states or autonomous regions in Europe, North America and Asia that implemented NIPT as part of a recommended antenatal screening policy for DS between 2011 and 2023 (Fig 2). Eight were retrospective cohort studies of population-based data [11,13,15,20,21,[26][27][28], evaluating the implementation of NIPT into their screening programmes for DS, and four were prospective cohort studies [14,[29][30][31]. Also included were eight official government documents describing the implementation of NIPT [12,[32][33][34][35][36][37][38] and one study that undertook a survey of clinical experts worldwide, providing data on multiple countries [16].…”

Rethinking second‐trimester Down‐syndrome screening in the cell‐free DNA era

“…In conventional screening practice, not all women with a screen‐positive result undergo invasive prenatal diagnosis, and there is evidence that if a secondary cfDNA protocol is adopted, the number of women having neither cfDNA nor invasive prenatal diagnosis will be decreased. Four out of the five studies of women with screen‐positive result comparing uptake before and after initiating the study found such a decrease, even though cfDNA testing was not free of charge. Assuming a decrease from 20% in conventional screening to 10% in a secondary cfDNA protocol, if the proportion presenting late was 15%, the combined test/quad test conventional protocol would cost €533 000 and the secondary cfDNA/primary cfDNA protocol would cost €550 000.…”

“…Tables 1 and 2 make the simplifying assumption of complete uptake of screening, invasive prenatal diagnosis and cfDNA testing. Seven studies have been published in which women with positive Down-syndrome screening results were offered the choice between invasive prenatal diagnosis and cfDNA testing [17][18][19][20][21][22][23] . These show no consistent overwhelming preference for one or the other test.…”

“…These show no consistent overwhelming preference for one or the other test. However, apart from two studies, the cfDNA test was either self‐paid (in Hong Kong and Germany) or, in the case of the California Prenatal Screening Program, covered by MediCal insurance for only about one‐third of those screened. In one of the two studies in which the cfDNA test was free of charge, the choice was confounded by the inclusion of chromosomal microarray (CMA) analysis with invasive prenatal diagnosis.…”