GE Medical Systems 500, User Manual, Page: 279 / 636

OB Measurements and Formulas
LOGIQ 500 Basic Users Manual
2276612–100 Rev. 0
9–17

Other OB Calculation Formulas (cont’d)
Calc
Mnemonic Calc Name
Input
Measurements Formula
Author
Reference
BPD Biparietal
Diameter one distance Curve data is
available in the
Advanced Reference Hadlock, JUM 1:97, 1982
AC Abdominal
Circumference circumference by
trace, ellipse, circle
or two distances
Advanced Reference
Manual
Hadlock, AJR, 139 : 367,
1982
HC Head
Circumference circumference by
trace, ellipse, circle
or two distances Hadlock, AJR, 138 : 649,
1982
CRL Crown Rump
Length one distance NELSON
BPD Biparietal
Diameter one distance KURTZ
BD Binocular
Distance one distance BERKOWITZ
EFW Estimated
Fetal Weight Average of BPD and
Average of TAD
[mm] EFW[kg] = 0.515263
–(0.105775*BPD)+
(0.000930707*
(BPD)
2
) +
(0.0649145*TAD) –
(0.00020562*
(TAD[mm])
2
)
German
EFW Estimated
Fetal Weight Average of BPD and
Average of AC [cm] EFW [g] =
10
ƞ
(3–1.7492 +
0.046*AC +
0.166*BPD –
0.002646*AC*BPD)
Shepard : Richards/
Berkowitz
EFW Estimated
Fetal Weight Average of FL,
Average of AC and
Average of HC [cm] EFW [g] =
10
ƞ
(1.5662 –
(0.0108*HC) +
(0.0468*AC) +
(0.171*FL) +
(0.00034*(HC)
2
) –
(0.003685*AC*FL) )
Hadlock, Radiology,
150 : 535, 1984
FL/HC FL/HC ratio Average of FL and
Average of HC FL/HC Hadlock, JUM, 3 : 439,
1984
Table 9–6. OB Calculation Formulas—Other Selections (cont’d)