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Book

Embryology, Umbilical Cord

Jenna R. Heil  1 , Bruno Bordoni  2
In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan.
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Book

Embryology, Umbilical Cord

Jenna R. Heil et al.
Free Books & Documents

Excerpt

The umbilical cord is the vital connection between the fetus and the placenta. Umbilical cord development begins in the embryologic period around week 3 with the formation of the connecting stalk. By week 7, the umbilical cord has fully formed, composed of the connecting stalk, vitelline duct, and umbilical vessels surrounding the amniotic membrane. The umbilical vessels carry the fetal blood back and forth to the placenta, with the umbilical vein carrying oxygenated blood with nutrients from the placenta to the fetus and the umbilical arteries transporting deoxygenated blood with waste products from the fetus to the placenta. Embryonic structures regress near the end of the first trimester, leaving the umbilical cord composed of two umbilical arteries and one umbilical vein surrounding by a gelatin-like extracellular matrix known as Wharton’s jelly. Elongation of the umbilical cord occurs primarily in the second trimester. The average umbilical cord is 50 to 60 centimeters in length, 2 centimeters in diameter, with up to 40 helical turns. Abnormalities of the umbilical cord can lead to increased morbidity and mortality of the fetus.

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Conflict of interest statement

Disclosure: Jenna Heil declares no relevant financial relationships with ineligible companies.

Disclosure: Bruno Bordoni declares no relevant financial relationships with ineligible companies.

References

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