By Adam Cloe – Updated March 24, 2022
The umbilical cord is a vital lifeline that connects a fetus to its mother, enabling survival before birth. It performs three core functions: supplying oxygen, delivering nutrients, and removing waste. Beyond its prenatal role, cord blood is increasingly used in medicine as a rich source of stem cells.
Across mammals, the umbilical cord represents a unique adaptation that sustains fetal development. In humans, the cord is cut shortly after birth, while other species may chew it off or allow it to dry naturally. Understanding its importance helps explain why it remains a focus of obstetric care and research.
The cord originates from two fetal structures: the yolk sac and the allantois. Both contribute to the cord’s composition, reflecting its role as part of the developing organism.
1. Oxygen Supply – The single umbilical vein carries oxygenated blood directly to the fetus, ensuring cellular respiration in the absence of lungs.
2. Nutrient Delivery – The cord transports essential calories, proteins, fats, vitamins, and minerals from the mother’s bloodstream to the fetus, supporting growth.
3. Waste Removal – Deoxygenated blood and metabolic waste are carried back through the two arteries to the mother’s circulation for processing and excretion.
The cord’s structure is unique: it is surrounded by Wharton’s jelly, a gelatinous connective tissue that cushions vessels and protects against compression. The vein splits into two branches within the fetal liver—one feeding the hepatic portal vein and the other becoming the ductus venosus, which routes about 80% of the blood directly to the fetal heart, bypassing the liver for efficient oxygen and nutrient distribution.
After delivery, cord blood can be harvested and stored in public or private banks. Its stem cells are valuable for treating blood and immune disorders, and certain cancers. Unlike bone marrow transplants, cord blood stem cells require less stringent donor matching, making them an attractive therapeutic option.
