obstetric US: fetal outer to outer biparietal diameter estimated from gestational age by Chitty 1994
obstetric us: fetal outer to outer biparietal diameter estimated from gestational age by chitty 1994
obstetric US: fetal outer to outer biparietal diameter estimated from gestational age by Chitty 1994 (procedure)
obstetric us: fetal outer to outer biparietal diameter estimated from gestational age by chitty 1994 (procedure)