多普勒超声测量胎儿大脑中动脉血流在高危妊娠中的研究进展

Research Progress of Doppler Ultrasound in the Measurement of the Fet al Middle Cerebral Artery Blood Flow in High-Risk Pregnancy

胎儿大脑中动脉(MCA)是大脑半球血液供应最丰富的血管,约占脑组织血液灌注(HP)量的70%,可动态反映胎儿脑循环变化。在正常妊娠时伴随孕周增加、胚胎发育,胎儿脑血管逐渐发育,管径增粗,血流阻力降低,脑容量逐渐增大,相应的血液供应及需氧量也逐渐增加;而阻力指数(RI)却随着孕周增加,呈降低趋势。但在高危妊娠时,则呈不同变化。妊娠14孕周后,即可采用多普勒超声检测MCA血流对高危妊娠进行早期诊断。多普勒超声测量胎儿MCA血流对母儿安全、无创,可减少诸如脐静脉及羊膜腔穿刺等有创性检查。产科多普勒超声在评估胎儿宫内安危方面有重要作用。作者拟就利用多普勒超声测量胎儿MCA血流在高危妊娠中的研究进展综述如下。

Fetal middle cerebral artery （MCA） blood supply to the brain hemisphere is the most abundant blood vessel, accounting for approximately 70% of the brain tissue for hemoperfusion（HP）, which can reflect the dynamic changes in fetal cerebral circulation. Embryonic development, gradual development of fetal brain blood vessels, diameter thickening,vascular resistance decreased, brain size increases in normal pregnancy with the increase of the gestational age, the blood supply and demand oxygen will increase gradually. The impedance index with the increase of gestational age showed a decreasing trend~ but in high- risk pregnancies will show a different variation. Doppler ultrasound can detect this change after 14 weeks of pregnancy, which chosen when high-risk pregnancy occurs are safe, non-invasive to mother and fetal, thereby reducing the umbilical vein and amniotic puncture. Obstetric Doppler ultrasound play an important role in the evaluation of fetal safety. This research focused on Doppler ultrasound in the measurement of the fetal MCA blood flow in high-risk pregnancy.