Table 5. Predictive accuracy of the last ultrasound exam for detecting abnormal growth.
| USE | Control | |
|---|---|---|
| Small for gestational agea | ||
| Sensitivity | 67% (31–91%) | 9% (0.5–43%) |
| Specificity | 98% (90–99%) | 98% (90–100%) |
| Positive predictive value | 85% (42–99%) | 50% (2–98%) |
| Negative predictive value | 95% (86–99%) | 86% (76–93%) |
| Positive likelihood ratio | 41.3 (5.6–304.8) | 5.7 (0.38–84.9) |
| Negative likelihood ratio | 0.33 (0.13–0.85) | 0.92 (0.76–1.11) |
| Large for gestational ageb | ||
| Sensitivity | 80% (30–99%) | NC |
| Specificity | 79% (66–87%) | 95% (86–98%) |
| Positive predictive value | 22% (7–48%) | 5% (1–13%) |
| Negative predictive value | 77% (52–93%) | 94% (86–98%) |
| Positive likelihood ratio | 3.7 (1.9–7.14) | NC |
| Negative likelihood ratio | 0.2 (0.04–1.47) | NC |
Abbreviations: NC, not calculable because of 0 in one of the cells; USE, ultrasonographic examination.
Note: Data presented as % (95% confidence intervals) or N.
a
Birth weight < 10% for gestational age using the nomogram of Alexander et al.33
b
Birth weight > 90% for gestational age using the nomogram of Alexander et al.33