Table 2 Performance of cfDNA assay for screening of trisomies 13, 18, 21
| Â | Sensitivity | Specificity |
|---|---|---|
Trisomy 21 | 19/19 = 100% (CI 95% 82.4–100) | 458/458 = 100% (CI 95% 99.2–100) |
Trisomy 18 | 3/3 = 100% (CI 95% 29.2–100) | 471/474 = 99.4% (CI 95% 98.2–99.9) |
Trisomy 13 | 0/0 | 476/477 = 99.8% (CI 95% 98.9–100) |