Gestational age:Time:Pt:^Fetus:Qn:US+Estimated from CRL.Yeh 1988
gestational age:time:pt:^fetus:qn:us+estimated from crl.yeh 1988
Gestational age estimated from Crown rump length on US by Yeh 1988 method
gestational age estimated from crown rump length on us by yeh 1988 method