obstetric US: fetal biparietal diameter estimated from gestational age by Merz 1988 method
obstetric us: fetal biparietal diameter estimated from gestational age by merz 1988 method
obstetric US: fetal biparietal diameter estimated from gestational age by Merz 1988 method (procedure)
obstetric us: fetal biparietal diameter estimated from gestational age by merz 1988 method (procedure)