Huikeshoven F J, Hope I D, Power G G, Gilbert R D, Longo L D
Am J Obstet Gynecol. 1985 Feb 15;151(4):449-55. doi: 10.1016/0002-9378(85)90268-6.
Human fetal cardiac output measured with ultrasound is only about 60% of that found in the sheep. We modified a previously developed mathematical model of the fetal circulation and oxygen delivery in sheep for the human in order to study several differences. The model predicts that a human fetus can maintain its oxygen delivery with a relatively low cardiac output because of its relatively high fetal hemoglobin concentration, as compared with that of the sheep fetus. Thus an inverse relationship between fetal hemoglobin concentration and fetal cardiac output is suggested. This relationship may be mediated by the influence of red blood cell concentration on blood viscosity. Furthermore, it indicates that fetal anemia should be detectable by ultrasound measurements of increased cardiac output and/or umbilical blood flow. Dynamic responses of the model suggest that the mechanism of late and variable decelerations in the fetal heart rate pattern is mediated via a fall in arterial oxygen tension.
用超声测量的人类胎儿心输出量仅约为绵羊胎儿心输出量的60%。我们修改了先前为绵羊开发的胎儿循环和氧输送的数学模型以用于人类，以便研究一些差异。该模型预测，与绵羊胎儿相比，人类胎儿由于其相对较高的胎儿血红蛋白浓度，能够以相对较低的心输出量维持其氧输送。因此，提示胎儿血红蛋白浓度与胎儿心输出量之间存在反比关系。这种关系可能由红细胞浓度对血液粘度的影响介导。此外，这表明胎儿贫血应该可以通过心输出量增加和/或脐血流的超声测量来检测。该模型的动态反应表明，胎儿心率模式中晚期和变异减速的机制是通过动脉氧分压下降介导的。
