LOINC long common name : Fetal Head Diameter.occipito-frontal US;
LOINC short name : Fet Head OFD US.meas;
LOINC description : Distance from frontal to occipital bone measured in same plane as biparietal diameter.
Authors vary but seems most reasonable to use outer to outer edge in determining circumference.
Measurement used to derive circumference and cephalic index.;