Risk of detecting brain abnormalities on iuMR relative to the degree of VM of the fetusa
| Mild VM | Moderate VM | Severe VM | |
|---|---|---|---|
| Overall risk of another brain abnormality | 6% (2%–12%) | 14% (4%–2%) | 57% (37%–76%) |
| 5/90 | 4/29 | 16/28 | |
| Overall relative risk compared with mild VM | 1 | 2.5 (0.7–8.6) | 10.3 (4.1–25.6)b |
| Risk of another brain abnormality in 20–24 w group | 6% (2%–14%) | 17% (4%–41%) | 22% (3%–60%) |
| 4/72 | 3/18 | 2/9 | |
| Relative risk compared with mild VM (20–24 w) | 1 | 3.0 (0.7–12.2) | 4.0 (0.8–18.8) |
| Risk of another brain abnormality in 25 w+ group | 6% (0%–27%) | 9% (0%–41%) | 74% (49%–91%) |
| 1/18 | 1/11 | 14/19 | |
| Relative risk compared with mild VM (25 w+) | 1 | 1.6 (0.1–23.6) | 13.3 (1.9–90.8)b |
Note:—VM indicates ventriculomegaly; w, week.
a Figures in brackets indicate 95% confidence intervals.
b Statistical significance at the <.05% level.