'Targeted' Cell-Free Fetal DNA Screening For Trisomy May Limit Costs
HealthDay News — Limiting first trimester screening (FTS) by cell-free fetal (cff) DNA to only patients in certain risk categories may be a feasible cost-containing strategy, according to a study published online June 27 in the Journal of Evaluation in Clinical Practice.
Lucia Rosignoli, PhD, MD, from Hospital Meyer in Florence, and Gabriele Tonni, PhD, MD, of the Guastalla Civil Hospital in Reggio Emilia – both in Italy, conducted a cost-benefit analysis of a hypothetical model based on implementation of FTS test by cff DNA in a population of 6,697 women. A two-step strategy was applied that was based on nuchal translucency, serum screening, and ultrasound assessment of nasal bone (NB). Intermediate-risk women underwent NB assessment, while fetal karyotyping was offered to all women at high risk.
The researchers found that 4.8% of women were high risk. A total of 7.1% were intermediate risk, and they underwent NB assessment, which was absent in 15 fetuses. Fifty-four aneuploidies were detected for a sensitivity of 96.4%, specificity of 96.1%, negative predictive value of 99.9%, and false-positive rate of 4.8%. Audit was conducted annually and 0.47% of cases were lost to follow-up. Based on assumed scenario, the team found that implementation of FTS by cff DNA in women at high-risk would result in a six-fold reduction in invasive procedures, and avoidance of two false negative results.
"At this stage, public health [systems], either from high- or low-resource [countries], would not be able to meet the expenses of adding non-invasive prenatal testing to first trimester screening test on a universal basis, a strategy that would invariably result in additional costs," the authors write. "Nonetheless, cff DNA could be offered to 'targeted' mothers (e.g. those with a FTS result as intermediate risk), thus limiting costs."