Gestational age:Time:Pt:^Fetus:Qn:US+Estimated from FL.Chitty 1997
gestational age:time:pt:^fetus:qn:us+estimated from fl.chitty 1997
Gestational age estimated from Femur length on US by Chitty 1997 method
gestational age estimated from femur length on us by chitty 1997 method