Fetal Cerebral Arterial Blood Perfusion in Normal and High-Risk Pregnancy
1Radiology, I.M. Sechenov First Moscow State Medical University, Russia
2Ultrasound and functional diagnostics, V.I. Kulakov Scientific Center of Obstetrics, Gynecology and Perinatology, Russia
Fetal with fetal growth restriction (FGR) are at increased risk for acidemia, hypoxemia and adverse perinatal outcomes. Placental insufficiency and FGR are the most common and important clinical problems in obstetrics and the leading causes of perinatal morbidity and mortality. Lots of diagnostic procedures are assessed to evaluate FGR, among them ultrasounds are the most relevant ones.
Objective: to evaluate changes in cerebral arterial bloodperfusion in fetuses in normal and high-risk pregnancy.
Materials and Methods. The study included 84 fetuses, which were divided into two groups. Resistant Index (RI) of anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) in PW mode and color Doppler mode was recorded of 52 (61.9%) fetuses under normal gestation (I group) and 32 (38.1%) fetuses at high risk pregnancies (II group). Cerebral bloodperfusion data were compared with bloodflow in the umbilical artery (PA) of the fetus, uterine artery and perinatal outcomes.
Results. At normal pregnancy there is an increase of RI during the end of III trimester (IR-0,78-0,80) in all cerebral arteries of the circle of Willis, with a gradual decrease to 37-40weeks (IR-0,71-0,73). In high-risk pregnancies IR values reduced in all cerebral arteries with progressive gestational age with the lowest IR values in the ACA (median, 0.70) at 28-32 weeks. In group I patients, the birth occurred on time without perinatal losses. In the group II, 5 cases of significant adverse outcomes (15.6%) were noted, including 4 cases of postnatal death and 1 case of perinatal death.
Figure 1. Spectrum of bloodflow velocity of ACA with duplex scanning in the axial plane of scanning
Figure 2. Spectrum of bloodflow velocity of ACA with duplex scanning in the sagittal plane of scanning
Conclusions. With a complicated course of pregnancy, the hemodynamics of the fetus changes with an increase in blood flow in all cerebral arteries (circulation centralization). There is the redistribution of the fetal perfusion with increased blood flow in the cerebral arteries (brain sparing effect) in high-risk pregnancies. Doppler signs of the brain-sparing were most obvious in the ACA, as compared to the MCA and PCA.