Table 5.
Test characteristics based on combinations of abnormal serum analytes for PAPP-A, MS-AFP, and Inhibin-A on the risk of placental abruption
| Serum analyte percentile | Test characteristic (95% confidence interval) | |||||
|---|---|---|---|---|---|---|
|
| ||||||
| PAPP-A | Maternal Serum AFP | Inhibin-A | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
| 11–89% | 11–89% | 11–89% | - | - | ||
| ≤5% | 12.0 (6.7–19.3) | 94.0 (93.7–94.4) | 1.3 (0.7–2.1) | 99.4 (99.3–99.5) | ||
| ≥95% | 8.9 (4.3–14.1) | 95.3 (95.0–95.6) | 1.2 (0.6–2.2) | 99.4 (99.3–99.5) | ||
| ≥95% | 11–89% | 7.2 (3.2–13.7) | 95.1 (94.7–95.4) | 0.1 (0.1–1.8) | 99.4 (99.3–99.5) | |
| ≤5% | - | 99.9 (99.8–99.9) | - | 99.4 (99.3–99.5) | ||
| ≥95% | 3.7 (1.0–9.3) | 99.1 (98.9–99.2) | 2.4 (0.7–6.1) | 99.4 (99.3–99.5) | ||
| ≤5% | 11–89% | 11–89% | 12.0 (6.7–19.3) | 94.6 (94.2–94.9) | 1.4 (0.1–2.4) | 99.4 (99.3–99.5) |
| ≤5% | 1.9 (0.0–6.7) | 99.4 (99.3–99.5) | 2.0 (0.0–7.0) | 99.4 (99.3–99.5) | ||
| ≥95% | 1.0 (0.0–5.2) | 99.6 (99.5–99.7) | 1.4 (0.0–7.6) | 99.4 (99.3–99.5) | ||
| ≥95% | 11–89% | 1.0 (0.0–5.2) | 99.6 (99.5–99.7) | 1.5 (0.0–8.0) | 99.4 (99.3–99.5) | |
| ≤5% | - | 100.0 (-) | - | 99.4 (99.3–99.5) | ||
| ≥95% | 1.9 (0.0–6.7) | 99.8 (99.7–99.9) | 5.3 (0.1–17.8) | 99.4 (99.3–99.5) | ||
PAPP-A, pregnancy-associated plasma protein A; AFP, alpha fetoprotein; PPV, positive predictive value; NPV, negative predictive value
The 95% confidence intervals were estimated based on the exact binomial proportion method