[Fetal brain blood flow velocity monitoring in high risk pregnancies]

Blood velocity in the fetal vein of Galen and straight sinus is normally even and without fluctuation. Transverse sinus blood velocity pattern shows a characteristic triphasic shape. The aim of this study was to establish whether blood flow velocity pulsations in the Galen vein, straight sinus and transverse sinus velocimetry in high-risk pregnancies are related to an adverse outcome.

The Galen vein, straight sinus and transverse sinus were located by color Doppler ultrasound in 110 pregnancies complicated by pregnancy-induced hypertension and intra-uterine growth retardation with blood velocity recorded by pulsed Doppler. The incidences of blood velocity pulsations in Galen vein and straight sinus as well as peak systolic velocity, lowest diastolic velocity and resistance index (RI) from transverse sinus were correlated to pregnancy outcome, including emergency operative intervention and/or neonatal distress. Umbilical artery and venous and uterine and middle cerebral artery blood velocity was also recorded at the same time.

Pulsating blood velocity in the Galen vein and transverse sinus was found in 40 and 10 cases, respectively. Signs of brain sparing in the middle cerebral artery were seen in 23 fetuses. Abnormal values for RI, peak systolic velocity and lowest diastolic velocity from transverse sinus were found in 20.6 and 18 cases, respectively. Galen vein pulsations were highly significantly related to adverse outcome of pregnancy and significantly more frequent in the present study than in the umbilical vein. Parameters studied in straight sinus and transverse sinus showed poor correlation with outcome of pregnancy.

Venous pulsations in the Galen vein are significantly correlated to adverse outcome of high-risk pregnancy. Straight sinus and transverse sinus velocimetry was not associated with perinatal outcome and might not be useful in predicting fetal distress.