Bellotti M, Pennati G, De Gasperi C, Battaglia F C, Ferrazzi E
Department of Obstetrics and Gynecology, University of Milan, 20142 Milan, Italy.
Am J Physiol Heart Circ Physiol. 2000 Sep;279(3):H1256-63. doi: 10.1152/ajpheart.2000.279.3.H1256.
Color Doppler sonography was used to study umbilical and ductus venosus (DV) flow in 137 normal fetuses between 20 and 38 wk of gestation. Hepatic flows were also evaluated. In all parts of the venous circulation examined, blood flow increased significantly with advancing gestational age. The weight-specific amniotic umbilical flow did not change significantly during gestation (120 +/- 44 ml. min(-1). kg(-1)), whereas DV flow decreased significantly (from 60 to 17 ml. min(-1). kg(-1)). The percentage of umbilical blood flow shunted through the DV decreased significantly (from 40% to 15%); consequently, the percentage of flow to the liver increased. The right lobe flow changed from 20 to 45%, whereas the left lobe flow was approximately constant (40%). These changes are related to different patterns of growth of the umbilical veins and DV diameters. The present data support the hypothesis that the DV plays a less important role in shunting well-oxygenated blood to the brain and myocardium in late normal pregnancy than in early gestation, which leads to increased fetal liver perfusion.
采用彩色多普勒超声研究了137例孕20至38周正常胎儿的脐静脉和静脉导管（DV）血流情况。同时也评估了肝脏血流。在所检查的静脉循环的各个部位，血流均随孕周增加而显著增加。妊娠期间，按体重计算的羊膜脐血流无显著变化（120±44 ml·min⁻¹·kg⁻¹），而DV血流显著减少（从60降至17 ml·min⁻¹·kg⁻¹）。经DV分流的脐血流百分比显著降低（从40%降至15%）；因此，流向肝脏的血流百分比增加。右叶血流从20%变为45%，而左叶血流大致恒定（40%）。这些变化与脐静脉和DV直径的不同生长模式有关。目前的数据支持这样一种假说，即与妊娠早期相比，在正常妊娠晚期，DV在将氧合良好的血液分流至脑和心肌方面所起的作用较小，这导致胎儿肝脏灌注增加。
