Gestational age:Time:Pt:^Fetus:Qn:US+Estimated from HC measured.Chitty 1997
gestational age:time:pt:^fetus:qn:us+estimated from hc measured.chitty 1997
Gestational age estimated from Head circumference measured on US by Chitty 1997 method
gestational age estimated from head circumference measured on us by chitty 1997 method