Locci M, Nazzaro G, De Placido G, Montemagno U
Department of Gynecology and Obstetrics, University of Naples, II Medical School, Italy.
J Perinat Med. 1992;20(5):337-43. doi: 10.1515/jpme.1992.20.5.337.
The importance of studying, by Doppler ultrasound, the cerebral haemodynamics to monitor the fetal response to the hypoxia is well known, but there is not a general agreement about the anatomical landmarks for the middle cerebral artery. Seventy-one normal fetuses and fifteen IUGR fetuses were studied. The umbilical artery and the middle cerebral artery (MCA) were evaluated by color Doppler ultrasound. The well-known decrease of the pulsatility index from the umbilical artery was observed throughout pregnancy. This velocimetric pattern did not occur in the IUGR fetuses. Four IUGR fetuses showed the ARED (absent or reversed and diastolic flow) pattern. The MCA was evaluated at the origin (M1) and at the distal tract (M2). PI values from M1 and M2 decreased during the pregnancy. A significant difference was detected between M1 and M2 PI values from the 26th to the 37th week of gestation. The M1 brain sparing effect was detected in the IUGR fetuses. Two ARED fetuses, observed during labor, showed the M2 sparing effect. The different Doppler patterns found in M1 and M2 could be due to the functional differences existing between these tracts. As a matter of fact, M1 and M2 supply different parts of the fetal brain, which develop in different periods of fetal life. These findings, if ulteriorly confirmed, could offer new perspectives for the monitoring of high risk fetuses.
通过多普勒超声研究脑血流动力学以监测胎儿对缺氧的反应，其重要性已广为人知，但对于大脑中动脉的解剖学标志尚无普遍共识。研究了71例正常胎儿和15例宫内生长受限（IUGR）胎儿。通过彩色多普勒超声评估脐动脉和大脑中动脉（MCA）。在整个孕期观察到脐动脉搏动指数的明显下降。这种血流速度模式在IUGR胎儿中未出现。4例IUGR胎儿表现出ARED（舒张期血流缺失或反向）模式。在大脑中动脉的起始段（M1）和远端段（M2）进行评估。M1和M2的搏动指数（PI）值在孕期下降。在妊娠第26至37周期间，M1和M2的PI值存在显著差异。在IUGR胎儿中检测到M1脑保护效应。在分娩期间观察到的2例ARED胎儿表现出M2保护效应。在M1和M2中发现的不同多普勒模式可能是由于这些节段之间存在的功能差异。事实上，M1和M2为胎儿大脑的不同部分供血，这些部分在胎儿生命的不同时期发育。如果这些发现得到进一步证实，可能会为高危胎儿的监测提供新的视角。
