| Gestational age, weeks | Mean kidney length, cm | 95% CI, cm |
| 18 | 2.2 | 1.6 - 2.8 |
| 19 | 2.3 | 1.5 - 3.1 |
| 20 | 2.6 | 1.8 - 3.4 |
| 21 | 2.7 | 2.1 - 3.2 |
| 22 | 2.7 | 2.0 - 3.4 |
| 23 | 3.0 | 2.2 - 3.7 |
| 24 | 3.1 | 1.9 - 4.4 |
| 25 | 3.3 | 2.5 - 4.2 |
| 26 | 3.4 | 2.4 - 4.4 |
| 27 | 3.5 | 2.7 - 4.4 |
| 28 | 3.4 | 2.6 - 4.2 |
| 29 | 3.6 | 2.3 - 4.8 |
| 30 | 3.8 | 2.9 - 4.6 |
| 31 | 3.7 | 2.8 - 4.6 |
| 32 | 4.1 | 3.1 - 5.1 |
| 33 | 4.0 | 3.3 - 4.7 |
| 34 | 4.2 | 3.3 - 5.0 |
| 35 | 4.2 | 3.2 - 5.2 |
| 36 | 4.2 | 3.3 - 5.0 |
| 37 | 4.2 | 3.3 - 5.1 |
| 38 | 4.4 | 3.2 - 5.6 |
| 39 | 4.2 | 3.5 - 4.8 |
| 40 | 4.3 | 3.2 - 5.3 |
| 41 | 4.5 | 3.9 - 5.1 |
