Table 3.
The proportions of dizygotic pregnancies where one, or both, fetal fractions (FFs) were below the limit of reliable interpretation sub‐classified by levels of total FF.
| Total FF | No. of Pregnancies | One Fetus < 4% | Two Fetuses < 4% | One Fetus < 2.8% | Two Fetuses < 2.8% |
|---|---|---|---|---|---|
| ≥10% | 2,215 | 63 (2.8%) | 0 (0%) | 19 (0.9%) | 0 (0%) |
| ≥8% to 10% | 480 | 166 (34.6%) | 0 (0%) | 11 (2.3%) | 0 (0%) |
| ≥6% to 8% | 359 | 151 (42.1%) | 208 (57.9%) | 54 (15.0%) | 0 (0%) |
| ≥4% to 6% | 100 | 2 (2%) | 98 (98.0%) | 63 (63.0%) | 24 (24.0%) |
| ≥2% to 4% | 7 | 0 (0%) | 7 (100%) | 0 (0%) | 7 (100%) |
| Any | 3,161 | 382 (12.1%) | 313 (9.9%) | 147 (4.7%) | 31 (1.0%) |