Gestational age:Time:Pt:^Fetus:Qn:US+Estimated from GSD.Daya 1991
gestational age:time:pt:^fetus:qn:us+estimated from gsd.daya 1991
Gestational age estimated from Gestational sac diameter on US by Daya 1991 method
gestational age estimated from gestational sac diameter on us by daya 1991 method