Terason t3000 / Echo Ultrasound System User Guide
322
Appendix D Gestational Tables
This appendix contains gestational tables for the measurements included with the
Obstetrical exam type:
• AC Chart, Hadlock, 12-42 weeks
• BPD Chart, Hadlock, 12.1 - 41.6 weeks
• CRL Chart, Hadlock, 5.7 - 18 weeks
• FL Chart, Hadlock, 12.2 - 42 weeks
• GSD, Hansmann - 6.0 - 14.0 weeks
• HC Chart, Hadlock, 12.2-41.9 weeks
• HL Chart, Jeanty, 12.6 - 40.1 weeks
Calculating Estimated Fetal Weight
on page 162 describes the procedure for measuring an
obstetrical scan to estimate the fetal weight. This calculation is based on the Hadlock
tables in this Appendix, and uses this formula:
EFW[g] = 10^
(
1.326 - (0.00326 * AC[cm] * FL[cm]) + (0.0107 * HC[cm]) + (0.0438 * AC[cm])
+ (0.158 * FL[cm])
)
where:
AC Chart, Hadlock, 12-42 weeks
EFW
Estimated Fetal Weight
AC
Abdominal Circumference
HC
Head Circumference
FL
Femur Length
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
AC
(mm)
MA
(wks)
51
12.1
93
15.5
135
19.0
177
22.6
219
26.4
261
30.2
304
34.4
346
38.5
52
12.2
94
15.5
136
19.0
178
22.7
220
26.4
262
30.3
305
34.5
347
38.6
53
12.2
95
15.6
137
19.1
179
22.8
221
26.5
263
30.4
306
34.6
348
38.7
54
12.3
96
15.7
138
19.2
180
22.9
222
26.6
264
30.5
307
34.7
349
38.8
55
12.4
97
15.8
139
19.3
181
22.9
223
26.7
265
30.6
308
34.7
350
38.9
56
12.5
98
15.9
140
19.4
182
23.0
224
26.8
266
30.7
309
34.8
351
39.0
57
12.5
99
15.9
141
19.5
183
23.1
225
26.9
267
30.8
310
34.9
352
39.1
58
12.6
100
16.0
142
19.6
184
23.2
226
27.0
268
30.9
311
35.0
353
39.2
59
12.7
101
16.1
143
19.6
185
23.3
227
27.1
269
31.0
312
35.1
354
39.3
60
12.8
102
16.2
144
19.7
186
23.4
228
27.2
270
31.1
313
35.2
355
39.4
61
12.9
103
16.3
145
19.8
187
23.5
229
27.3
271
31.2
314
35.3
356
39.5
