An equation proposed in Rose (1987) uses abdominal diameter, biparietal diameter and femoral diaphysis length to estimate fetal weight. The use of three parameters can offer improved accuracy when compared to equations using one or two parameters. Femur length has the advantage of accurately reflecting fetal growth patterns. Measurement of abdominal diameter can be done more accurately than abdominal circumference.


estimated fetal weight in grams =

= e ^ (4.198 + (0.143 * ((abdominal diameter in cm) + (biparietal diameter in cm) + (femoral diaphysis length in cm))))



• Biparietal diameter can be affected by variation in cranial shape.


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