Fetal measurements and estimated fetal weight (EFW) can be compared with previous measurements of the same fetus to longitudinally evaluate the growth.
BPD and head circumference (HC) are measured in the axial plane of fetal head (Figure 19.1).
Abdominal circumference (AC) is measured where the transverse diameter of the liver is greatest (Figure 19.2).
This is considered the most variable and most difficult measurement.