Lingman G, Marsál K
Department of Obstetrics and Gynecology, Central Hospital, Helsingborg, Sweden.
Biol Neonate. 1989;56(3):129-35. doi: 10.1159/000243113.
The blood velocity in the common carotid artery, umbilical artery and descending aorta of 15 term fetuses with birth weights appropriate for gestational age and 20 fetuses, ultrasonically suspected of intrauterine growth retardation (IUGR), was recorded by means of a technique combining real-time linear-array ultrasonography and 2-MHz pulsed Doppler ultrasound. The waveform of the maximum blood velocity was characterized by a pulsatility index (PI) indicating peripheral vascular resistance. In the normal fetuses, the mean PI was 1.89 (+/- 0.07 SEM) in the common carotid artery, 0.93 (+/- 0.04) in the umbilical artery and 2.19 (+/- 0.06) in the descending aorta. In the IUGR fetuses, the PI was higher than in the normal fetuses in the umbilical artery (1.19 +/- 0.04; p less than 0.05) and lower in the carotid artery (1.48 +/- 0.03; p less than 0.05). The changes of the PI were even more pronounced in 10 IUGR fetuses in whom cardiotocographic signs (late decelerations) of imminent asphyxia were present. The results indicate an increase in the peripheral vascular resistance in the placental circulation and the lower body, and a decrease in the cranial vascular resistance in the growth-retarded fetuses. Furthermore, these findings suggest that in chronic and acute fetal distress, there is a redistribution of the fetal circulation favoring the brain.
采用实时线性阵列超声和2兆赫脉冲多普勒超声相结合的技术，记录了15例出生体重与孕周相符的足月胎儿以及20例超声怀疑有宫内生长迟缓（IUGR）胎儿的颈总动脉、脐动脉和降主动脉中的血流速度。最大血流速度波形的特征是搏动指数（PI），其表明外周血管阻力。正常胎儿中，颈总动脉的平均PI为1.89（±0.07标准误），脐动脉为0.93（±0.04），降主动脉为2.19（±0.06）。在IUGR胎儿中，脐动脉的PI高于正常胎儿（1.19±0.04；p＜0.05），而颈动脉的PI低于正常胎儿（1.48±0.03；p＜0.05）。在10例有即将发生窒息的心电图体征（晚期减速）的IUGR胎儿中，PI的变化更为明显。结果表明，生长迟缓胎儿的胎盘循环和下半身外周血管阻力增加，而颅血管阻力降低。此外，这些发现表明，在慢性和急性胎儿窘迫中，胎儿循环会重新分布，有利于大脑。
