Gestational age, wks | Percentiles | ||||||||
---|---|---|---|---|---|---|---|---|---|
3rd | 5th | 10th | 25th | 50th | 75th | 90th | 95th | 97th | |
Biparietal diameter, mm (MC & DC twins) | |||||||||
14 | 25.9 | 26.2 | 26.7 | 27.4 | 28.3 | 29.1 | 30.0 | 30.5 | 30.8 |
15 | 28.7 | 29.0 | 29.5 | 30.3 | 31.3 | 32.2 | 33.1 | 33.7 | 34.0 |
16 | 31.5 | 31.9 | 32.4 | 33.3 | 34.3 | 35.4 | 36.4 | 37.0 | 37.4 |
17 | 34.5 | 34.8 | 35.4 | 36.4 | 37.5 | 38.7 | 39.8 | 40.4 | 40.8 |
18 | 37.5 | 37.9 | 38.5 | 39.6 | 40.8 | 42.0 | 43.2 | 43.9 | 44.4 |
19 | 40.5 | 40.9 | 41.6 | 42.7 | 44.1 | 45.4 | 46.7 | 47.4 | 47.9 |
20 | 43.5 | 44.0 | 44.7 | 46.0 | 47.4 | 48.8 | 50.1 | 51.0 | 51.5 |
21 | 46.6 | 47.1 | 47.8 | 49.2 | 50.6 | 52.2 | 53.6 | 54.5 | 55.1 |
22 | 49.6 | 50.1 | 50.9 | 52.3 | 53.9 | 55.5 | 57.1 | 58.0 | 58.6 |
23 | 52.6 | 53.1 | 54.0 | 55.5 | 57.1 | 58.9 | 60.5 | 61.4 | 62.1 |
24 | 55.5 | 56.1 | 57.0 | 58.5 | 60.3 | 62.1 | 63.8 | 64.8 | 65.5 |
25 | 58.3 | 58.9 | 59.9 | 61.5 | 63.3 | 65.2 | 67.0 | 68.1 | 68.8 |
26 | 61.1 | 61.7 | 62.7 | 64.4 | 66.3 | 68.3 | 70.1 | 71.2 | 72.0 |
27 | 63.7 | 64.3 | 65.4 | 67.1 | 69.1 | 71.2 | 73.1 | 74.3 | 75.0 |
28 | 66.2 | 66.9 | 68.0 | 69.8 | 71.8 | 74.0 | 76.0 | 77.2 | 78.0 |
29 | 68.6 | 69.3 | 70.4 | 72.3 | 74.4 | 76.6 | 78.7 | 79.9 | 80.7 |
30 | 70.9 | 71.6 | 72.7 | 74.7 | 76.9 | 79.1 | 81.2 | 82.5 | 83.4 |
31 | 73.0 | 73.8 | 74.9 | 76.9 | 79.2 | 81.5 | 83.7 | 85.0 | 85.8 |
32 | 75.0 | 75.8 | 77.0 | 79.0 | 81.3 | 83.7 | 85.9 | 87.3 | 88.2 |
33 | 76.9 | 77.7 | 78.9 | 81.0 | 83.4 | 85.8 | 88.1 | 89.4 | 90.3 |
34 | 78.7 | 79.5 | 80.7 | 82.9 | 85.3 | 87.7 | 90.0 | 91.4 | 92.4 |
35 | 80.4 | 81.2 | 82.4 | 84.6 | 87.0 | 89.6 | 91.9 | 93.3 | 94.3 |
36 | 81.9 | 82.7 | 84.0 | 86.2 | 88.7 | 91.3 | 93.6 | 95.1 | 96.1 |
37 | 83.4 | 84.2 | 85.5 | 87.7 | 90.3 | 92.9 | 95.3 | 96.8 | 97.7 |
38 | 84.8 | 85.6 | 87.0 | 89.2 | 91.8 | 94.4 | 96.8 | 98.3 | 99.3 |
Head circumference, mm (MC & DC twins) | |||||||||
14 | 92.4 | 93.2 | 94.6 | 96.8 | 99.4 | 102.1 | 104.6 | 106.1 | 107.1 |
15 | 102.6 | 103.5 | 105.0 | 107.5 | 110.4 | 113.4 | 116.1 | 117.7 | 118.8 |
16 | 113.2 | 114.2 | 115.8 | 118.6 | 121.8 | 125.0 | 128.0 | 129.8 | 131.0 |
17 | 124.1 | 125.2 | 127.0 | 130.0 | 133.4 | 137.0 | 140.2 | 142.2 | 143.5 |
18 | 135.2 | 136.4 | 138.3 | 141.6 | 145.3 | 149.2 | 152.7 | 154.8 | 156.3 |
19 | 146.4 | 147.7 | 149.8 | 153.3 | 157.3 | 161.5 | 165.3 | 167.6 | 169.1 |
20 | 157.7 | 159.1 | 161.3 | 165.1 | 169.4 | 173.8 | 177.9 | 180.4 | 182.0 |
21 | 168.9 | 170.4 | 172.8 | 176.8 | 181.4 | 186.1 | 190.5 | 193.1 | 194.8 |
22 | 180.0 | 181.6 | 184.1 | 188.4 | 193.3 | 198.2 | 202.9 | 205.7 | 207.5 |
23 | 190.9 | 192.6 | 195.2 | 199.8 | 204.9 | 210.1 | 215.0 | 218.0 | 219.9 |
24 | 201.5 | 203.3 | 206.1 | 210.8 | 216.2 | 221.7 | 226.8 | 230.0 | 232.0 |
25 | 211.8 | 213.7 | 216.6 | 221.6 | 227.2 | 233.0 | 238.3 | 241.5 | 243.7 |
26 | 221.7 | 223.7 | 226.7 | 231.9 | 237.7 | 243.8 | 249.3 | 252.7 | 254.9 |
27 | 231.2 | 233.3 | 236.4 | 241.8 | 247.8 | 254.1 | 259.8 | 263.3 | 265.6 |
28 | 240.3 | 242.4 | 245.6 | 251.2 | 257.4 | 263.9 | 269.8 | 273.5 | 275.8 |
29 | 248.8 | 251.0 | 254.3 | 260.1 | 266.5 | 273.2 | 279.3 | 283.0 | 285.5 |
30 | 256.9 | 259.1 | 262.6 | 268.4 | 275.1 | 281.9 | 288.2 | 292.0 | 294.5 |
31 | 264.6 | 266.8 | 270.3 | 276.3 | 283.2 | 290.1 | 296.6 | 300.5 | 303.1 |
32 | 271.7 | 274.0 | 277.6 | 283.7 | 290.7 | 297.8 | 304.4 | 308.4 | 311.0 |
33 | 278.4 | 280.8 | 284.4 | 290.7 | 297.8 | 305.0 | 311.7 | 315.8 | 318.5 |
34 | 284.7 | 287.1 | 290.8 | 297.2 | 304.4 | 311.8 | 318.6 | 322.8 | 325.5 |
35 | 290.7 | 293.1 | 296.9 | 303.3 | 310.7 | 318.1 | 325.1 | 329.3 | 332.0 |
36 | 296.3 | 298.7 | 302.6 | 309.1 | 316.5 | 324.1 | 331.1 | 335.4 | 338.2 |
37 | 301.6 | 304.1 | 308.0 | 314.6 | 322.1 | 329.8 | 336.9 | 341.2 | 344.1 |
38 | 306.8 | 309.3 | 313.2 | 319.9 | 327.5 | 335.3 | 342.5 | 346.8 | 349.7 |
Abdominal circumference, mm (MC & DC twins) | |||||||||
14 | 77.8 | 78.7 | 80.1 | 82.5 | 85.3 | 88.2 | 90.9 | 92.5 | 93.6 |
15 | 86.8 | 87.8 | 89.4 | 92.1 | 95.2 | 98.4 | 101.4 | 103.2 | 104.4 |
16 | 96.3 | 97.4 | 99.1 | 102.1 | 105.5 | 109.1 | 112.4 | 114.4 | 115.7 |
17 | 106.0 | 107.2 | 109.1 | 112.4 | 116.2 | 120.0 | 123.6 | 125.9 | 127.3 |
18 | 116.0 | 117.3 | 119.4 | 123.0 | 127.1 | 131.3 | 135.2 | 137.6 | 139.2 |
19 | 126.1 | 127.6 | 129.8 | 133.7 | 138.1 | 142.7 | 146.9 | 149.5 | 151.2 |
20 | 136.4 | 138.0 | 140.4 | 144.5 | 149.3 | 154.2 | 158.8 | 161.6 | 163.4 |
21 | 146.7 | 148.4 | 151.0 | 155.4 | 160.5 | 165.7 | 170.6 | 173.6 | 175.6 |
22 | 157.0 | 158.7 | 161.5 | 166.2 | 171.7 | 177.2 | 182.4 | 185.6 | 187.7 |
23 | 167.1 | 169.0 | 172.0 | 177.0 | 182.7 | 188.6 | 194.1 | 197.5 | 199.7 |
24 | 177.2 | 179.2 | 182.3 | 187.6 | 193.6 | 199.9 | 205.7 | 209.2 | 211.6 |
25 | 187.1 | 189.1 | 192.4 | 198.0 | 204.3 | 210.9 | 217.0 | 220.7 | 223.2 |
26 | 196.7 | 198.9 | 202.3 | 208.1 | 214.8 | 221.7 | 228.0 | 231.9 | 234.5 |
27 | 206.2 | 208.5 | 212.0 | 218.1 | 225.0 | 232.2 | 238.8 | 242.9 | 245.5 |
28 | 215.4 | 217.8 | 221.4 | 227.8 | 235.0 | 242.4 | 249.3 | 253.5 | 256.3 |
29 | 224.4 | 226.8 | 230.7 | 237.2 | 244.7 | 252.4 | 259.5 | 263.9 | 266.8 |
30 | 233.2 | 235.7 | 239.6 | 246.4 | 254.1 | 262.1 | 269.5 | 274.0 | 277.0 |
31 | 241.7 | 244.3 | 248.4 | 255.4 | 263.4 | 271.6 | 279.2 | 283.8 | 286.9 |
32 | 250.1 | 252.8 | 257.0 | 264.2 | 272.4 | 280.9 | 288.7 | 293.5 | 296.7 |
33 | 258.5 | 261.2 | 265.5 | 272.9 | 281.3 | 290.0 | 298.1 | 303.0 | 306.3 |
34 | 266.7 | 269.5 | 274.0 | 281.6 | 290.2 | 299.1 | 307.4 | 312.4 | 315.8 |
35 | 275.0 | 277.9 | 282.4 | 290.2 | 299.1 | 308.2 | 316.7 | 321.9 | 325.3 |
36 | 283.3 | 286.3 | 291.0 | 298.9 | 308.0 | 317.4 | 326.1 | 331.4 | 334.9 |
37 | 291.8 | 294.9 | 299.7 | 307.8 | 317.1 | 326.7 | 335.6 | 341.1 | 344.7 |
38 | 300.6 | 303.8 | 308.7 | 317.0 | 326.6 | 336.4 | 345.5 | 351.1 | 354.7 |
Femur length, mm (MC & DC twins) | |||||||||
14 | 13.1 | 13.3 | 13.6 | 14.1 | 14.7 | 15.3 | 15.9 | 16.3 | 16.5 |
15 | 15.4 | 15.6 | 15.9 | 16.5 | 17.2 | 17.9 | 18.6 | 19.0 | 19.2 |
16 | 17.8 | 18.0 | 18.4 | 19.1 | 19.8 | 20.6 | 21.4 | 21.8 | 22.1 |
17 | 20.3 | 20.5 | 21.0 | 21.7 | 22.6 | 23.5 | 24.3 | 24.8 | 25.2 |
18 | 22.9 | 23.2 | 23.6 | 24.5 | 25.4 | 26.4 | 27.4 | 27.9 | 28.3 |
19 | 25.5 | 25.9 | 26.4 | 27.3 | 28.3 | 29.4 | 30.5 | 31.1 | 31.5 |
20 | 28.2 | 28.6 | 29.1 | 30.1 | 31.3 | 32.5 | 33.6 | 34.2 | 34.7 |
21 | 30.9 | 31.3 | 31.9 | 32.9 | 34.2 | 35.4 | 36.6 | 37.4 | 37.8 |
22 | 33.5 | 33.9 | 34.6 | 35.7 | 37.0 | 38.4 | 39.7 | 40.4 | 40.9 |
23 | 36.1 | 36.5 | 37.2 | 38.4 | 39.8 | 41.2 | 42.6 | 43.4 | 43.9 |
24 | 38.5 | 39.0 | 39.7 | 41.0 | 42.5 | 44.0 | 45.4 | 46.2 | 46.8 |
25 | 40.9 | 41.4 | 42.2 | 43.5 | 45.0 | 46.6 | 48.0 | 48.9 | 49.5 |
26 | 43.2 | 43.7 | 44.5 | 45.8 | 47.4 | 49.0 | 50.5 | 51.5 | 52.1 |
27 | 45.3 | 45.8 | 46.6 | 48.1 | 49.7 | 51.4 | 52.9 | 53.9 | 54.5 |
28 | 47.3 | 47.9 | 48.7 | 50.2 | 51.8 | 53.5 | 55.1 | 56.1 | 56.7 |
29 | 49.2 | 49.8 | 50.7 | 52.1 | 53.8 | 55.6 | 57.2 | 58.2 | 58.8 |
30 | 51.1 | 51.6 | 52.5 | 54.0 | 55.7 | 57.5 | 59.2 | 60.2 | 60.8 |
31 | 52.8 | 53.4 | 54.3 | 55.8 | 57.5 | 59.3 | 61.0 | 62.0 | 62.7 |
32 | 54.5 | 55.1 | 56.0 | 57.5 | 59.3 | 61.1 | 62.8 | 63.8 | 64.5 |
33 | 56.2 | 56.8 | 57.7 | 59.3 | 61.0 | 62.9 | 64.6 | 65.6 | 66.3 |
34 | 57.9 | 58.5 | 59.4 | 61.0 | 62.8 | 64.6 | 66.3 | 67.4 | 68.1 |
35 | 59.6 | 60.2 | 61.2 | 62.8 | 64.6 | 66.4 | 68.2 | 69.2 | 69.9 |
36 | 61.5 | 62.1 | 63.0 | 64.6 | 66.5 | 68.3 | 70.1 | 71.1 | 71.8 |
37 | 63.5 | 64.1 | 65.0 | 66.6 | 68.5 | 70.4 | 72.1 | 73.2 | 73.9 |
38 | 65.6 | 66.3 | 67.2 | 68.9 | 70.7 | 72.7 | 74.4 | 75.5 | 76.2 |