Perimeter:Len:Pt:Head^Fetus:Qn:US.derived from OFD&O-I BPD
perimeter:len:pt:head^fetus:qn:us.derived from ofd&o-i bpd
Fetal Head Circumference derived from occipital-frontal diameter and outer-inner biparietal diameter (US)
fetal head circumference derived from occipital-frontal diameter and outer-inner biparietal diameter (us)