A case of a four-vessel umbilical cord: don't stop counting at three!
Accessory Vessels of the Umbilical Cord
Umbilical cord - Wikipedia
Umbilical Cord Vessels
Umbilical Cord Tissue Cells: Challenges and Promise
BIR Publications
Learning About a Single Umbilical Artery
What is the umbilical cord? | BabyCenter
The umbilical cord, which connects your baby to the placenta, contains three vessels: two arteries, which carry blood… | Cell therapy, Stem cell therapy, Stem cells