Magann, E F Amniotic fluid index estimation of amniotic fluid volume must be validated. [electronic resource] - American journal of obstetrics and gynecology Sep 1996 - 757-8 p. digital Publication Type: Letter; Comment ISSN: 0002-9378 Subjects--Topical Terms: Amniotic Fluid--diagnostic imagingFemaleHumansOligohydramnios--diagnostic imagingPregnancyTwinsUltrasonography, Prenatal