Wan Tianran, Johnstone Edward D, Saw Shier Nee, Jensen Oliver E, Chernyavsky Igor L
Department of Mathematics, University of Manchester, Manchester M13 9PL, UK.
Maternal and Fetal Health Research Centre, University of Manchester, Manchester M13 9WL, UK.
J R Soc Interface. 2025 Sep;22(230):20250148. doi: 10.1098/rsif.2025.0148. Epub 2025 Sep 24.
The umbilical cord plays a critical role in delivering nutrients and oxygen from the placenta to the fetus through the umbilical vein, while the two umbilical arteries carry deoxygenated blood with waste products back to the placenta. Although solute exchange in the placenta has been extensively studied, exchange within the cord tissue has not been investigated. Here, we explore the hypothesis that the coiled structure of the umbilical cord could strengthen diffusive coupling between the arteries and the vein, resulting in a functional shunt. We calculate the diffusion of solutes, such as oxygen, and heat in the umbilical cord to quantify how this shunt is affected by vascular configuration within the cord. We demonstrate that the shunt is enhanced by coiling and vessel proximity. Furthermore, our model predicts that typical vascular configurations of the human cord tend to minimize shunting, which could otherwise disrupt thermal regulation of the fetus. We also show that the exchange, amplified by coiling, can provide additional oxygen supply to the cord tissue surrounding the umbilical vessels.
脐带在通过脐静脉将营养物质和氧气从胎盘输送到胎儿的过程中起着关键作用，而两条脐动脉则将携带代谢废物的脱氧血液输送回胎盘。尽管胎盘内的溶质交换已得到广泛研究，但脐带组织内的交换尚未得到研究。在此，我们探讨这样一种假设，即脐带的盘绕结构可加强动脉与静脉之间的扩散耦合，从而形成功能性分流。我们计算了脐带中氧气和热量等溶质的扩散，以量化这种分流如何受到脐带内血管构型的影响。我们证明，盘绕和血管靠近会增强分流。此外，我们的模型预测，人类脐带的典型血管构型往往会使分流最小化，否则可能会干扰胎儿的体温调节。我们还表明，由盘绕放大的交换可为脐血管周围的脐带组织提供额外的氧气供应。
