Table 6.
Umbilical artery systolic/diastolic ratio (male)
| Gestation (week) | 2.5th percentile | 5th percentile | 10th percentile | 25th percentile | Mean | 75th percentile | 90th percentile | 95th percentile | 97.5th percentile |
|---|---|---|---|---|---|---|---|---|---|
| 20 | 2.6 | 2.7 | 2.9 | 3.3 | 3.9 | 4.6 | 5.5 | 6.3 | 7.1 |
| 21 | 2.5 | 2.7 | 2.8 | 3.2 | 3.7 | 4.4 | 5.3 | 6.0 | 6.7 |
| 22 | 2.4 | 2.6 | 2.8 | 3.1 | 3.6 | 4.3 | 5.1 | 5.7 | 6.4 |
| 23 | 2.4 | 2.5 | 2.7 | 3.0 | 3.5 | 4.1 | 4.9 | 5.5 | 6.1 |
| 24 | 2.3 | 2.4 | 2.6 | 2.9 | 3.4 | 4.0 | 4.7 | 5.3 | 5.8 |
| 25 | 2.2 | 2.4 | 2.5 | 2.8 | 3.3 | 3.8 | 4.5 | 5.0 | 5.6 |
| 26 | 2.2 | 2.3 | 2.5 | 2.8 | 3.2 | 3.7 | 4.4 | 4.9 | 5.4 |
| 27 | 2.1 | 2.2 | 2.4 | 2.7 | 3.1 | 3.6 | 4.2 | 4.7 | 5.2 |
| 28 | 2.1 | 2.2 | 2.3 | 2.6 | 3.0 | 3.5 | 4.1 | 4.5 | 5.0 |
| 29 | 2.0 | 2.1 | 2.3 | 2.5 | 2.9 | 3.4 | 3.9 | 4.3 | 4.8 |
| 30 | 2.0 | 2.1 | 2.2 | 2.5 | 2.8 | 3.3 | 3.8 | 4.2 | 4.6 |
| 31 | 1.9 | 2.0 | 2.1 | 2.4 | 2.7 | 3.2 | 3.7 | 4.1 | 4.5 |
| 32 | 1.9 | 2.0 | 2.1 | 2.3 | 2.7 | 3.1 | 3.6 | 3.9 | 4.3 |
| 33 | 1.8 | 1.9 | 2.0 | 2.3 | 2.6 | 3.0 | 3.5 | 3.8 | 4.2 |
| 34 | 1.8 | 1.9 | 2.0 | 2.2 | 2.5 | 2.9 | 3.4 | 3.7 | 4.1 |
| 35 | 1.7 | 1.8 | 1.9 | 2.2 | 2.5 | 2.8 | 3.3 | 3.6 | 3.9 |
| 36 | 1.7 | 1.8 | 1.9 | 2.1 | 2.4 | 2.8 | 3.2 | 3.5 | 3.8 |
| 37 | 1.7 | 1.8 | 1.9 | 2.1 | 2.3 | 2.7 | 3.1 | 3.4 | 3.7 |
| 38 | 1.6 | 1.7 | 1.8 | 2.0 | 2.3 | 2.6 | 3.0 | 3.3 | 3.6 |
| 39 | 1.6 | 1.7 | 1.8 | 2.0 | 2.2 | 2.6 | 2.9 | 3.2 | 3.5 |
| 40 | 1.6 | 1.6 | 1.7 | 1.9 | 2.2 | 2.5 | 2.9 | 3.1 | 3.4 |
Sex-specific reference values of the umbilical artery systolic/diastolic (UA S/D) ratio for the 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97.5th percentiles during the second half of pregnancy (male fetuses)