de Vries Ivar R, Oei S Guid, van der Hout-van der Jagt M Beatrijs, Dirkx Joost A J, Vullings Rik, Vis Jolande Y, Broeren Maarten A C, van Laar Judith O E H
Department of Obstetrics and Gynecology, Máxima Medical Centre, Veldhoven, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; Eindhoven MedTech Innovation Centre (e/MTIC), Eindhoven, the Netherlands.
Department of Obstetrics and Gynecology, Máxima Medical Centre, Veldhoven, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; Eindhoven MedTech Innovation Centre (e/MTIC), Eindhoven, the Netherlands; Nemo Healthcare BV, Veldhoven, the Netherlands.
Placenta. 2025 Jul 12;169:1-7. doi: 10.1016/j.placenta.2025.07.007.
The human umbilical cord at term typically consists of two arteries and one vein. Fetuses with a single umbilical artery are known to have increased risk of perinatal morbidity and mortality. However, the role of the dual umbilical artery in reducing these risk remains poorly understood. In this work, we hypothesize that the increased arterial wall surface provided by the dual umbilical artery facilitates the diffusion of carbon dioxide (CO) between the fetal blood and Wharton's jelly to allow temporary CO storage.
We flushed blood plasma with high and low CO content through umbilical cord segments, and measured the blood gas content of the outflowing liquid periodically.
The hypothesized diffusion was proven by a linear relationship between estimated diffusion capacity and cord length for three different experimental analyses (all p < 0.001).
This diffusion capacity provides a threefold protection of the fetus from acidosis during uterine contractions. Firstly, the cord dampens the increase in CO in the fetal blood during a contraction, thereby protecting against acute acidosis. Secondly, the diffusion of CO from Wharton's jelly back into the arterial blood accelerates fetal recovery after a contraction through its interaction with the Bohr and Haldane effects. Finally, our results indicate a diffusion capacity for oxygen as well, through which the umbilical cord may act as a fetal oxygen reserve. Since the study design does not allow for estimation of the clinical relevance of this threefold effect, future research should focus on determining the clinical impact of this diffusion capacity, enabling the adaptation of obstetric management strategies for fetuses with relevant cord anomalies.
足月时的人类脐带通常由两条动脉和一条静脉组成。已知单脐动脉胎儿围产期发病率和死亡率增加。然而，双脐动脉在降低这些风险中的作用仍知之甚少。在本研究中，我们假设双脐动脉提供的增加的动脉壁表面积有助于二氧化碳（CO）在胎儿血液和华通氏胶之间扩散，以实现二氧化碳的临时储存。
我们通过脐带段用高二氧化碳含量和低二氧化碳含量的血浆冲洗，并定期测量流出液体的血气含量。
在三种不同的实验分析中，估计的扩散能力与脐带长度之间的线性关系证明了假设的扩散（所有p < 0.001）。
这种扩散能力为胎儿在子宫收缩期间提供了三重保护，使其免受酸中毒。首先，脐带抑制了收缩期间胎儿血液中二氧化碳的增加，从而防止急性酸中毒。其次，二氧化碳从华通氏胶扩散回动脉血中，通过其与玻尔效应和哈代效应的相互作用加速了收缩后的胎儿恢复。最后，我们的结果还表明存在氧气扩散能力，通过这种能力脐带可能充当胎儿的氧气储备。由于本研究设计不允许估计这种三重效应的临床相关性，未来的研究应侧重于确定这种扩散能力的临床影响，从而能够调整针对有相关脐带异常胎儿的产科管理策略。
