Gynecology, Obstetrics and Perinatology

A Doppler assessment of vascular hemodynamics in the vertebrobasilar system of the fetus in physiological and compromised pregnancy

The study presents the findings of a complex dynamic ultrasound and Doppler examination of fetal blood flow in 71 pregnant women. It has been found that diagnostic signs of placental insufficiency are not only changes in fetoplacental and uteroplacental hemodynamics, but also fetal blood flow, including impaired circulation in the fetal vertebrobasilar system. Characteristic indices for impaired circulation in the vertebral arteries include a symmetrical or asymmetrical increase of the S/D ratio above 4.0, PI above 1.7- in the basilar artery – S/D ratio above 4.2, PI above 1.8. In threatened miscarriage, impairments of hemodynamics are more marked in the fetal/placental unit and regional blood vessels of the fetus involving the vertebrobasilar system, however an early beginning of therapy of this complication of pregnancy and placental insufficiency led to eventual normalization. In gestosis, the impairments are determined by severity of placental insufficiency, fetal hypoxia and formation of FGRS. Impaired fetal circulation develops in the presence of marked disorders of uteroplacental hemodynamics, and impairments of cerebral circulation depend not so much on impaired circulation in the fetal vertebrobasilar system as on severity of hypoxia.