Perimeter:Len:Pt:Head^Fetus:Qn:US.estimated from Merz 1988
perimeter:len:pt:head^fetus:qn:us.estimated from merz 1988
Fetal Head Circumference estimated from gestational age by method of Merz 1988 (US)
fetal head circumference estimated from gestational age by method of merz 1988 (us)