Age-specific reference intervals for fetal small and large intestinal lengths
| Age category (wk) | Number | Small intestinal length | Large intestinal length | ||
| Lower limit (90% CI) | Upper limit (90% CI) | Lower limit (90% CI) | Upper limit (90% CI) | ||
| 13–20 | 42 | 21.1 (10.7 to 30.8) | 122.4 (111.5 to 136.1) | 5.1 (3.4 to 6.7) | 21.4 (19.8 to 23.2) |
| 13–16 | 13 | _* | _ | _* | _ |
| 17–20 | 29 | 33.9 (23.4 to 49.0) | 127.1 (114.5 to 141.5) | 7.9 (6.2 to 9.9) | 21.7 (20.1 to 23.5) |
| 21–28 | 47 | 57.7 (40.8 to 73.3) | 203.8 (187.3 to 220.7) | 12.7 (10.1 to 14.9) | 39.7 (36.9 to 42.7) |
| 21–24 | 28 | 60.0 (40.0 to 78.2) | 185.8 (168.0 to 203.3) | 11.2 (7.7 to 14.7) | 36.7 (32.8 to 41.0) |
| 25–28 | 19 | 64.8 (39.4 to 89.5) | 230.9 (202.9 to 262.9) | 14.8 (9.0 to 19.5) | 44.2 (40.5 to 48.8) |
| 29–36 | 21 | 83.6 (30.5 to 127.7) | 337.1 (292.6 to 382.8) | 32.4 (28.3 to 36.1) | 62.4 (58.0 to 67.5) |
| 29–32 | 10 | _* | _ | _* | _ |
| 33–36 | 11 | _* | _ | _* | _ |
| 37–41 | 21 | 132.8 (85.7 to 171.5) | 406.4 (358.5 to 455.2) | 29.1 (20.6 to 36.5) | 82.2 (73.6 to 91.6) |
Bolded values represent collapsed age categories in this study and their associated fetal length reference intervals.
*Insufficient sample size for approximating reference intervals for intestinal length.
CI, Confidence interval.