Wittmann B K, Rurak D W, Gruber N, Brown S
Am J Obstet Gynecol. 1981 Dec 1;141(7):807-10. doi: 10.1016/0002-9378(81)90708-0.
In seven pregnant ewes with catheters chronically implanted in the fetus, real-time ultrasound observations of fetal breathing and body movements were correlated with direct measurements of fetal arterial and tracheal pressures, heart rate, and intrauterine pressure. There was excellent correlation between the ultrasound record of fetal breathing and recordings of intratracheal pressure changes even when breath amplitude was low or frequently was high. Fetal body movements (stretches, rolls, kicks) were observed during both breathing and nonbreathing periods; vigorous movements were accompanied by rapid deflections of the amniotic and tracheal pressure traces. Movement was frequently accompanied by transient increases or decreases in heart rate. The results indicate that real-time ultrasound is an accurate method of observation of fetal movement in pregnant sheep and is particularly valuable when combined with direct measurements of fetal physiologic parameters.
在七只胎儿长期植入导管的怀孕母羊中，对胎儿呼吸和身体运动的实时超声观察结果与胎儿动脉压、气管压、心率和宫内压的直接测量结果相关联。即使呼吸幅度较小或频率较高，胎儿呼吸的超声记录与气管内压力变化的记录之间仍具有极佳的相关性。在呼吸期和非呼吸期均观察到胎儿身体运动（伸展、翻滚、踢动）；剧烈运动伴随着羊膜和气管压力曲线的快速偏移。运动常常伴随着心率的短暂升高或降低。结果表明，实时超声是观察怀孕绵羊胎儿运动的一种准确方法，当与胎儿生理参数的直接测量相结合时，尤其有价值。
