Ultrasound Appendix 11

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 35.8 36.2 36.7 37.7 38.8 39.9 40.8 41.4 41.8 18 38.4 38.9 39.6 40.7 42.0 43.3 44.5 45.2 45.6 19 41.1 41.6 42.4 43.7 45.2 46.7 48.0 48.9 49.4 20 43.7 44.2 45.2 46.7 48.3 50.0 51.5 52.4 53.0 21 46.3 46.9 47.9 49.6 51.4 53.2 54.9 55.9 56.5 22 48.9 49.6 50.6 52.4 54.4 56.4 58.2 59.2 59.9 23 51.5 52.2 53.3 55.2 57.3 59.4 61.3 62.5 63.2 24 54.0 54.8 56.0 58.0 60.2 62.4 64.4 65.6 66.4 25 56.6 57.4 58.6 60.7 63.0 65.3 67.4 68.6 69.4 26 59.1 59.9 61.2 63.4 65.7 68.1 70.2 71.5 72.3 27 61.6 62.4 63.7 65.9 68.4 70.8 73.0 74.3 75.1 28 64.0 64.9 66.2 68.5 70.9 73.4 75.6 76.9 77.8 29 66.5 67.3 68.7 70.9 73.4 75.9 78.1 79.5 80.3 30 68.9 69.7 71.1 73.3 75.8 78.2 80.5 81.9 82.7 31 71.2 72.0 73.4 75.6 78.1 80.5 82.8 84.1 84.9 32 73.5 74.3 75.7 77.9 80.3 82.7 84.9 86.2 87.1 33 75.8 76.6 77.9 80.0 82.4 84.8 86.9 88.2 89.0 34 78.0 78.8 80.0 82.1 84.4 86.7 88.8 90.0 90.8 35 80.1 80.9 82.1 84.1 86.3 88.5 90.5 91.7 92.5 36 82.2 83.0 84.1 86.0 88.1 90.2 92.1 93.3 94.0 37 84.3 85.0 86.0 87.8 89.8 91.8 93.6 94.7 95.3 38 86.3 86.9 87.9 89.6 91.4 93.2 94.9 95.9 96.5 39 88.2 88.8 89.7 91.2 92.9 94.5 96.1 97.0 97.5 40 90.0 90.5 91.4 92.7 94.2 95.7 97.1 97.9 98.4 41 91.8 92.3 93.0 94.2 95.5 96.7 97.9 98.6 99.1 42 93.5 93.9 94.5 95.5 96.6 97.6 98.6 99.2 99.6

Table A.2 Nomograms (centiles) for the Italian population: head circumference (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 125.6 127.1 129.7 133.8 138.4 143.0 147.1 149.7 151.2 18 138.0 139.7 142.3 146.7 151.5 156.4 160.7 163.4 165.1 19 150.2 151.9 154.7 159.3 164.4 169.4 174.0 176.8 178.6 20 162.0 163.9 166.8 171.6 176.9 182.2 187.0 189.9 191.7 21 173.6 175.5 178.5 183.5 189.1 194.6 199.6 202.7 204.6 22 184.7 186.7 189.9 195.1 200.9 206.6 211.9 215.1 217.0 23 195.6 197.6 200.9 206.4 212.3 218.3 223.8 227.1 229.1 24 206.0 208.1 211.6 217.2 223.4 229.6 235.3 238.7 240.8 25 216.0 218.2 221.8 227.7 234.1 240.5 246.4 249.9 252.1 26 225.7 227.9 231.6 237.7 244.3 251.0 257.0 260.7 263.0 27 234.9 237.2 241.0 247.3 254.1 261.0 267.3 271.1 273.4 28 243.6 246.0 250.0 256.4 263.5 270.6 277.0 281.0 283.4 29 251.9 254.4 258.4 265.1 272.4 279.7 286.3 290.4 292.9 30 259.7 262.3 266.4 273.3 280.8 288.3 295.1 299.3 301.9 31 267.0 269.7 273.9 281.0 288.7 296.4 303.4 307.7 310.3 32 273.8 276.5 280.9 288.1 296.1 304.0 311.2 315.6 318.3 33 280.1 282.9 287.4 294.8 302.9 311.0 318.4 322.9 325.7 34 285.8 288.7 293.3 300.8 309.2 317.5 325.1 329.7 332.6 35 290.9 293.9 298.6 306.4 314.9 323.4 331.2 335.9 338.8 36 295.5 298.5 303.3 311.3 320.0 328.7 336.7 341.5 344.5 37 299.5 302.6 307.5 315.6 324.5 333.5 341.6 346.5 349.6 38 302.8 306.0 311.0 319.3 328.4 337.5 345.8 350.9 354.0 39 305.6 308.8 313.9 322.4 331.7 341.0 349.5 354.6 357.8 40 307.7 310.9 316.2 324.8 334.3 343.8 352.4 357.7 360.9 41 309.1 312.4 317.7 326.5 336.2 345.9 354.7 360.1 363.4 42 309.8 313.2 318.6 327.6 337.5 347.3 356.3 361.7 365.1

Table A.3 Nomograms (centiles) for the Italian population: abdominal circumference (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 113.3 114.8 117.3 121.4 125.9 130.4 134.5 137.0 138.5 18 122.0 123.8 126.7 131.6 137.0 142.3 147.2 150.1 152.0 19 130.6 132.7 136.1 141.7 147.9 154.0 159.6 163.0 165.1 20 139.3 141.7 145.5 151.8 158.7 165.6 171.9 175.7 178.1 21 148.0 150.6 154.8 161.7 169.3 176.9 183.9 188.1 190.7 22 156.7 159.5 164.1 171.6 179.8 188.1 195.6 200.2 203.0 23 165.4 168.4 173.3 181.3 190.2 199.0 207.1 212.0 215.0 24 174.0 177.2 182.4 191.0 200.4 209.7 218.3 223.5 226.7 25 182.7 186.0 191.5 200.5 210.4 220.2 229.2 234.7 238.1 26 191.2 194.8 200.5 209.9 220.2 230.5 239.9 245.6 249.1 27 199.8 203.5 209.4 219.1 229.8 240.5 250.3 256.2 259.9 28 208.3 212.1 218.2 228.2 239.3 250.3 260.4 266.5 270.3 29 216.7 220.6 226.9 237.2 248.5 259.8 270.2 276.4 280.3 30 225.1 229.1 235.5 246.0 257.5 269.1 279.6 286.0 290.0 31 233.4 237.5 243.9 254.6 266.4 278.1 288.8 295.3 299.3 32 241.7 245.7 252.3 263.1 275.0 286.8 297.6 304.2 308.3 33 249.8 253.9 260.5 271.4 283.3 295.3 306.1 312.7 316.8 34 257.9 262.0 268.6 279.5 291.4 303.4 314.3 320.9 325.0 35 265.8 269.9 276.5 287.4 299.3 311.3 322.1 328.7 332.8 36 273.7 277.7 284.3 295.1 307.0 318.8 329.6 336.2 340.2 37 281.4 285.4 291.9 302.6 314.3 326.1 336.7 343.2 347.2 38 289.0 293.0 299.4 309.9 321.4 333.0 343.5 349.9 353.8 39 296.5 300.4 306.6 316.9 328.3 339.6 349.9 356.1 360.0 40 303.9 307.6 313.7 323.8 334.8 345.8 355.9 362.0 365.8 41 311.1 314.7 320.6 330.4 341.1 351.8 361.5 367.4 371.1 42 318.1 321.7 327.4 336.7 347.0 357.3 366.7 372.4 375.9

Table A.4 Nomograms (centiles) for the Italian population: femur length (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 20.1 20.6 21.4 22.6 24.0 25.4 26.7 27.4 27.9 18 23.2 23.6 24.4 25.6 27.0 28.3 29.6 30.3 30.8 19 26.1 26.6 27.3 28.5 29.9 31.2 32.4 33.2 33.6 20 28.9 29.4 30.1 31.4 32.7 34.0 35.2 36.0 36.4 21 31.7 32.1 32.9 34.1 35.4 36.8 38.0 38.7 39.2 22 34.3 34.8 35.5 36.8 38.1 39.4 40.7 41.4 41.9 23 36.9 37.3 38.1 39.3 40.7 42.0 43.3 44.0 44.5 24 39.3 39.8 40.6 41.8 43.2 44.6 45.8 46.6 47.1 25 41.7 42.2 42.9 44.2 45.6 47.0 48.3 49.1 49.6 26 43.9 44.4 45.2 46.5 48.0 49.4 50.7 51.5 52.0 27 46.1 46.6 47.4 48.8 50.3 51.7 53.1 53.9 54.4 28 48.1 48.6 49.5 50.9 52.4 54.0 55.4 56.3 56.8 29 50.0 50.6 51.5 53.0 54.6 56.2 57.6 58.5 59.1 30 51.9 52.5 53.4 54.9 56.6 58.3 59.8 60.7 61.3 31 53.6 54.2 55.2 56.8 58.6 60.3 61.9 62.9 63.5 32 55.3 55.9 56.9 58.6 60.5 62.3 64.0 65.0 65.6 33 56.8 57.5 58.6 60.3 62.3 64.2 66.0 67.0 67.7 34 58.3 59.0 60.1 62.0 64.0 66.0 67.9 69.0 69.7 35 59.6 60.4 61.5 63.5 65.6 67.8 69.8 70.9 71.7 36 60.9 61.6 62.9 65.0 67.2 69.5 71.6 72.8 73.6 37 62.0 62.8 64.1 66.3 68.7 71.1 73.3 74.6 75.4 38 63.0 63.9 65.3 67.6 70.1 72.7 75.0 76.4 77.2 39 64.0 64.9 66.4 68.8 71.5 74.1 76.6 78.0 79.0 40 64.8 65.8 67.4 69.9 72.7 75.6 78.1 79.7 80.6 41 65.6 66.6 68.2 71.0 73.9 76.9 79.6 81.3 82.3 42 66.2 67.3 69.0 71.9 75.0 78.2 81.0 82.8 83.8

Table A.5 Nomograms (centiles) for the Italian population: tibia length (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 16.9 17.5 18.4 20.0 21.7 23.4 25.0 25.9 26.5 18 19.7 20.3 21.2 22.7 24.3 26.0 27.5 28.4 28.9 19 22.5 23.0 23.9 25.3 26.9 28.5 29.9 30.8 31.4 20 25.1 25.7 26.5 27.9 29.4 31.0 32.4 33.2 33.7 21 27.7 28.2 29.0 30.4 31.9 33.4 34.7 35.6 36.1 22 30.2 30.7 31.5 32.8 34.3 35.7 37.1 37.9 38.4 23 32.6 33.1 33.8 35.2 36.6 38.1 39.4 40.2 40.7 24 34.8 35.3 36.1 37.4 38.9 40.3 41.6 42.4 42.9 25 37.0 37.5 38.3 39.6 41.1 42.5 43.8 44.6 45.1 26 39.1 39.6 40.4 41.7 43.2 44.6 46.0 46.8 47.3 27 41.1 41.6 42.4 43.8 45.3 46.7 48.1 48.9 49.4 28 43.0 43.5 44.4 45.8 47.3 48.8 50.1 51.0 51.5 29 44.8 45.4 46.2 47.6 49.2 50.8 52.2 53.0 53.6 30 46.6 47.1 48.0 49.5 51.1 52.7 54.1 55.0 55.6 31 48.2 48.7 49.7 51.2 52.9 54.6 56.1 57.0 57.6 32 49.7 50.3 51.3 52.9 54.6 56.4 58.0 58.9 59.5 33 51.1 51.8 52.8 54.5 56.3 58.1 59.8 60.8 61.5 34 52.5 53.1 54.2 56.0 57.9 59.9 61.6 62.7 63.4 35 53.7 54.4 55.5 57.4 59.5 61.5 63.4 64.5 65.2 36 54.8 55.6 56.8 58.8 60.9 63.1 65.1 66.3 67.0 37 55.9 56.7 58.0 60.1 62.4 64.7 66.8 68.0 68.8 38 56.9 57.7 59.0 61.3 63.7 66.2 68.4 69.7 70.6 39 57.7 58.6 60.0 62.4 65.0 67.6 70.0 71.4 72.3 40 58.5 59.4 61.0 63.5 66.2 69.0 71.5 73.0 74.0 41 59.2 60.2 61.8 64.5 67.4 70.3 73.0 74.6 75.6 42 59.7 60.8 62.5 65.4 68.5 71.6 74.4 76.2 77.2

Table A.6 Nomograms (centiles) for the Italian population: humerus length (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 20.1 20.6 21.3 22.6 23.9 25.2 26.5 27.2 27.7 18 22.6 23.1 23.8 25.0 26.3 27.7 28.8 29.6 30.0 19 25.1 25.5 26.2 27.4 28.7 30.0 31.2 31.9 32.4 20 27.4 27.9 28.6 29.7 31.0 32.3 33.5 34.2 34.6 21 29.7 30.1 30.8 32.0 33.3 34.6 35.7 36.5 36.9 22 31.9 32.3 33.0 34.2 35.5 36.8 37.9 38.7 39.1 23 34.0 34.4 35.1 36.3 37.6 38.9 40.1 40.8 41.3 24 36.0 36.4 37.2 38.4 39.7 41.0 42.2 42.9 43.4 25 37.9 38.4 39.1 40.3 41.7 43.0 44.2 45.0 45.4 26 39.7 40.2 40.9 42.2 43.6 45.0 46.2 47.0 47.4 27 41.4 41.9 42.7 44.0 45.4 46.8 48.1 48.9 49.4 28 43.1 43.6 44.4 45.7 47.2 48.6 50.0 50.8 51.3 29 44.6 45.1 45.9 47.3 48.8 50.4 51.7 52.6 53.1 30 46.0 46.5 47.4 48.8 50.4 52.0 53.4 54.3 54.9 31 47.3 47.9 48.8 50.3 51.9 53.6 55.1 56.0 56.5 32 48.5 49.1 50.0 51.6 53.3 55.0 56.6 57.6 58.2 33 49.6 50.2 51.2 52.8 54.6 56.4 58.1 59.1 59.7 34 50.5 51.2 52.2 53.9 55.8 57.7 59.5 60.5 61.1 35 51.3 52.0 53.1 54.9 56.9 58.9 60.7 61.8 62.5 36 52.1 52.8 53.9 55.8 57.9 60.0 61.9 63.1 63.8 37 52.6 53.4 54.6 56.6 58.8 61.0 63.0 64.3 65.0 38 53.1 53.9 55.2 57.3 59.6 61.9 64.0 65.3 66.1 39 53.4 54.2 55.6 57.8 60.3 62.7 64.9 66.3 67.1 40 53.6 54.5 55.9 58.2 60.8 63.4 65.8 67.2 68.1 41 53.6 54.5 56.1 58.5 61.2 64.0 66.4 67.9 68.9 42 53.5 54.5 56.1 58.7 61.6 64.4 67.0 68.6 69.6

Table A.7 Nomograms (centiles) for the Italian population: ulna length (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 19.9 20.3 20.9 21.9 22.9 24.0 25.0 25.6 26.0 18 21.9 22.3 23.0 24.0 25.2 26.4 27.5 28.1 28.5 19 23.9 24.3 25.0 26.2 27.4 28.7 29.8 30.5 31.0 20 25.8 26.3 27.0 28.3 29.6 30.9 32.2 32.9 33.4 21 27.7 28.2 29.0 30.3 31.7 33.1 34.4 35.2 35.7 22 29.6 30.1 30.9 32.3 33.8 35.3 36.6 37.4 38.0 23 31.4 32.0 32.8 34.2 35.8 37.3 38.8 39.6 40.2 24 33.2 33.7 34.6 36.1 37.7 39.4 40.9 41.7 42.3 25 34.9 35.5 36.4 38.0 39.7 41.3 42.9 43.8 44.4 26 36.6 37.2 38.2 39.8 41.5 43.3 44.8 45.8 46.4 27 38.2 38.8 39.8 41.5 43.3 45.1 46.8 47.8 48.4 28 39.8 40.5 41.5 43.2 45.0 46.9 48.6 49.6 50.3 29 41.4 42.0 43.1 44.8 46.7 48.7 50.4 51.5 52.1 30 42.9 43.5 44.6 46.4 48.4 50.3 52.1 53.2 53.9 31 44.3 45.0 46.1 48.0 50.0 52.0 53.8 54.9 55.6 32 45.7 46.4 47.6 49.4 51.5 53.6 55.4 56.6 57.3 33 47.1 47.8 49.0 50.9 53.0 55.1 57.0 58.1 58.8 34 48.4 49.2 50.3 52.3 54.4 56.5 58.5 59.7 60.4 35 49.7 50.5 51.7 53.6 55.8 57.9 59.9 61.1 61.9 36 51.0 51.7 52.9 54.9 57.1 59.3 61.3 62.5 63.3 37 52.2 52.9 54.1 56.2 58.4 60.6 62.6 63.8 64.6 38 53.3 54.1 55.3 57.4 59.6 61.8 63.9 65.1 65.9 39 54.4 55.2 56.4 58.5 60.8 63.0 65.1 66.3 67.1 40 55.5 56.3 57.5 59.6 61.9 64.2 66.2 67.5 68.3 41 56.5 57.3 58.5 60.6 62.9 65.2 67.3 68.6 69.4 42 57.5 58.3 59.5 61.6 63.9 66.2 68.3 69.6 70.4

Table A.8 Nomograms (centiles) for the Italian population: radius length (mm)a

Gestational age (weeks) 3rd 5th 10th 25th 50th 75th 90th 95th 97th

17 17.2 17.5 18.0 18.9 19.8 20.7 21.5 22.0 22.3 18 19.2 19.5 20.1 21.0 22.0 23.1 24.0 24.6 24.9 19 21.1 21.4 22.1 23.1 24.3 25.4 26.4 27.1 27.5 20 22.9 23.3 24.0 25.2 26.4 27.7 28.8 29.5 29.9 21 24.7 25.1 25.9 27.1 28.5 29.8 31.1 31.8 32.3 22 26.4 26.9 27.7 29.0 30.5 31.9 33.3 34.1 34.6 23 28.1 28.6 29.4 30.9 32.4 34.0 35.4 36.2 36.8 24 29.7 30.2 31.1 32.6 34.3 35.9 37.4 38.3 38.9 25 31.2 31.8 32.8 34.3 36.1 37.8 39.4 40.3 40.9 26 32.7 33.3 34.3 36.0 37.8 39.6 41.3 42.3 42.9 27 34.1 34.8 35.8 37.6 39.4 41.3 43.1 44.1 44.8 28 35.5 36.2 37.3 39.1 41.0 43.0 44.8 45.9 46.5 29 36.8 37.5 38.7 40.5 42.5 44.6 46.4 47.5 48.2 30 38.1 38.8 40.0 41.9 44.0 46.1 48.0 49.1 49.9 31 39.3 40.0 41.2 43.2 45.3 47.5 49.5 50.6 51.4 32 40.4 41.2 42.4 44.4 46.6 48.8 50.9 52.1 52.8 33 41.5 42.3 43.6 45.6 47.9 50.1 52.2 53.4 54.2 34 42.6 43.4 44.6 46.7 49.0 51.3 53.4 54.7 55.5 35 43.5 44.3 45.6 47.8 50.1 52.5 54.6 55.9 56.7 36 44.5 45.3 46.6 48.7 51.1 53.5 55.7 57.0 57.8 37 45.3 46.1 47.5 49.7 52.1 54.5 56.7 58.0 58.8 38 46.1 47.0 48.3 50.5 52.9 55.4 57.6 58.9 59.8 39 46.9 47.7 49.1 51.3 53.7 56.2 58.4 59.8 60.6 40 47.5 48.4 49.8 52.0 54.5 57.0 59.2 60.6 61.4 41 48.2 49.0 50.4 52.7 55.1 57.6 59.9 61.3 62.1 42 48.8 49.6 51.0 53.2 55.7 58.2 60.5 61.9 62.7

Table A.9 HC/AC, HC/FL, and BPD/FL ratios (centiles) for the diagnosis of microcephalya

HC/AC HC/FL BPD/FL Gestational age (weeks) 5th 50th 95th 5th 50th 95th 5th 50th 95th

14 1.13 1.23 1.34 4.93 5.51 6.16 1.75 1.92 2.11 15 1.12 1.22 1.33 4.73 5.29 5.92 1.66 1.82 2.00 16 1.11 1.21 1.32 4.57 5.11 5.71 1.58 1.74 1.91 17 1.10 1.20 1.31 4.43 4.95 5.54 1.52 1.67 1.83 18 1.09 1.19 1.30 4.32 4.83 5.40 1.47 1.61 1.77 19 1.08 1.18 1.29 4.23 4.73 5.29 1.42 1.56 1.71 20 1.07 1.17 1.28 4.16 4.65 5.20 1.39 1.52 1.67 21 1.06 1.17 1.27 4.11 4.59 5.13 1.36 1.49 1.64 22 1.05 1.16 1.26 4.07 4.55 5.08 1.34 1.47 1.61 23 1.04 1.15 1.25 4.04 4.52 5.05 1.32 1.45 1.59 24 1.03 1.14 1.24 4.03 4.50 5.03 1.30 1.43 1.57 25 1.02 1.13 1.23 4.02 4.50 5.03 1.29 1.42 1.56 26 1.01 1.12 1.22 4.03 4.50 5.03 1.29 1.41 1.55 27 1.00 1.11 1.21 4.04 4.51 5.04 1.28 1.41 1.54 28 0.99 1.10 1.20 4.05 4.53 5.06 1.28 1.40 1.54 29 0.98 1.09 1.19 4.07 4.55 5.09 1.28 1.40 1.54 30 0.97 1.08 1.18 4.10 4.58 5.12 1.27 1.40 1.53 31 0.96 1.07 1.17 4.12 4.61 5.15 1.27 1.40 1.53 32 0.95 1.06 1.16 4.15 4.64 5.18 1.27 1.39 1.53 33 0.94 1.05 1.16 4.17 4.67 5.22 1.27 1.39 1.52 34 0.94 1.04 1.15 4.20 4.69 5.24 1.26 1.38 1.52 35 0.93 1.03 1.14 4.21 4.71 5.27 1.25 1.37 1.51 36 0.92 1.02 1.13 4.23 4.73 5.28 1.24 1.36 1.50 37 0.91 1.01 1.12 4.23 4.73 5.29 1.23 1.35 1.48 38 0.90 1.00 1.11 4.23 4.73 5.29 1.21 1.33 1.46 39 0.89 0.99 1.10 4.22 4.71 5.27 1.19 1.30 1.43 40 0.88 0.98 1.09 4.19 4.69 5.24 1.16 1.28 1.40

Table A.10 Nomograms (centiles): transverse cerebellar diameters (mm) for the diagnosis of cerebellar hypoplasiaa

Gestational age (weeks) 5th 50th 95th

14 12 13 14 15 13 14 16 16 14 15 17 17 15 17 18 18 16 18 20 19 17 19 21 20 18 20 22 21 20 22 24 22 21 24 27 23 22 24 27 24 23 26 28 25 25 27 30 26 26 28 31 27 27 30 33 28 28 31 34 29 30 33 36 30 31 34 37 31 32 35 39 32 33 37 40 33 35 38 42 34 36 39 43 35 37 41 45 36 38 42 46 37 39 43 47 38 40 44 48 39 41 45 49 40 42 46 51

Table A.11 Nomograms (centiles) – cerebellar vermis: anteroposterior (AP) diameter, supero-inferior (SI) diameter, circumference, and area for the diagnosis of vermian hypoplasia, partial agenesisa

Gestational AP diameter SI diameter Circumference Area age (weeks) (mm) (mm) (mm) (cm2)

21-22 10.6 ± 1.4 11.1 ± 1.1 43.8 ± 3.3 0.9 ± 0.2 23-24 12.9 ± 1.1 12.3 ± 1.4 47.5 ± 5.5 1.2 ± 0.2 25-26 13.5 ± 2.1 13.6 ± 0.9 50.9 ± 4.4 1.4 ± 0.2 27-28 16.3 ± 2.7 16.0 ± 1.6 58.9 ± 6.8 2.0 ± 0.5 29-30 17.5 ± 2.2 17.7 ± 2.1 64.7 ± 6.5 2.3 ± 0.4 31-32 19.0 ± 1.9 19.2 ± 1.1 70.7 ± 6.9 2.8 ± 0.4 33-34 19.2 ± 1.9 21.2 ± 2.3 72.7 ± 8.3 3.0 ± 0.8 35-36 21.4 ± 1.5 19.8 ± 1.0 77.6 ± 5.1 3.4 ± 0.3 37-38 22.1 ± 3.8 23.0 ± 4.6 80.7 ± 9.9 3.9 ± 1.4 39-40 25.7 ± 2.3 25.0 ± 2.6 86.7 ± 7.0 4.9 ± 0.7 a Modified, from: Malinger G, Ginath S, Lerman-Sagie T, et al. The fetal cerebellar vermis: normal development as shown by transvaginal ultrasound. Prenat Diagn 2001; 21: 687-92.