Gestational age:Time:Pt:^Fetus:Qn:US+Estimated from OOD.Trout 1994
gestational age:time:pt:^fetus:qn:us+estimated from ood.trout 1994
Gestational age estimated from Outer orbital distance on US by Trout 1994 method
gestational age estimated from outer orbital distance on us by trout 1994 method