Accuracy of ultrasonography in evaluating amniotic fluid volume at less than 24 weeks' gestation.
Magann EF, Whitworth NS, Klausen JH, Perry KG, Martin JN, Morrison JC. Accuracy of ultrasonography in evaluating amniotic fluid volume at less than 24 weeks' gestation. J Ultrasound Med. 1995 Dec; 14(12):895-7.