Blood redistribution in the fetal brain during chronic hypoxia.
BACKGROUND
Studies on blood flow velocity in the fetal middle cerebral artery have revealed signs of brain sparing in chronic hypoxia. These signs of brain sparing can disappear in the terminal case, but whether this applies to the whole brain or only parts of it is unknown.


METHODS
Velocity waveforms of the middle cerebral, anterior cerebral and posterior cerebral arteries were recorded in 221 pregnancies complicated by pregnancy-induced hypertension. The presence of brain sparing (pulsatility index < 2 standard deviations) was noted and correlated to outcome of pregnancy, including emergency operative intervention and/or neonatal distress.


RESULTS
Signs of brain sparing in the anterior cerebral artery were found in 90 fetuses, and in the middle cerebral and posterior cerebral arteries in 52 and 65, respectively. Signs of brain sparing in the anterior cerebral artery showed the strongest relationship to adverse perinatal outcome. The anterior cerebral artery was the only vessel in which signs of brain sparing were predictive of perinatal mortality.


CONCLUSIONS
Velocimetry of the anterior cerebral artery appears to be superior to that of the middle cerebral and posterior cerebral arteries as a means to predict adverse perinatal outcome. Anterior cerebral artery brain sparing may therefore be less transitory than sparing in the middle cerebral and posterior cerebral arteries, possibly suggesting that the frontal lobes are spared longer than the lateral and occipital regions of the fetal brain.
Dubiel
M
M
Department of Perinatology and Gynecology, University School of Medical Sciences, Poznan, Poland.
Gunnarsson
G O
GO
Gudmundsson
S
S
D000328:Adult; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply / Q000196:embryology*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002908:Chronic Disease; D004453:Echoencephalography; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002534:Hypoxia, Brain / Q000503:physiopathology*; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal