原 量宏, 柳原 敏宏, 神保 利春

Kazuhiro HARA, Toshihiro YANAGIHARA, Toshiharu JIMBO

香川医科大学母子科学

Department of Perinato-Gynecology, Kagawa Medical School

キーワード : Amniotic fluid volume, Hydramnios, Oligohydramnios, Real-time scanner

In this study, the accuracy of ultrasonic determination of amniotic fluid volume was investigated with the serial planimetry method and the Manning's Pocket method experimentally. Concerning the former method, the serial sections of a balloon which was inflated with water were measured using the ultrasonic real-time scanner. The areas of all serial sections were added and then compared with that of true volume of the balloon quantitatively, giving the detection error of this method about 10%. Therefore, the planimetry method is thought to be good enough for clinical use.
As for the Manning's method, saline was infused into amniotic cavity of a patient with Potter syndrome where amniotic fluid was completely absent. The distance between the fetus and the uterine wall was quantitatively measured. The linearity between the volume of infused water and the distance was relatively high (r=0.97). When the distance is less than 1 cm, the amniotic fluid volume can be estimated to be less than 100 ml On the other hand, when the distance is more than 8 cm, the amniotic fluid volume can be estimated to be more than 1000 ml. The Manning's Pocket method was proved to be also reliable and useful for clinical practice.