Observation:SpGrav:Pt:Amnio fld:Qn:Refractometry
observation:spgrav:pt:amnio fld:qn:refractometry
Observation:SpGrav:To identify measures at a point in time:Amniotic fluid:Quantitative:Refractometry
observation:spgrav:to identify measures at a point in time:amniotic fluid:quantitative:refractometry