Umbilical arteries (changes after birth)

The umbilical arteries obliterate after birth. It occurs by two means:

• functional obliteration:
  • occurs within a few minutes of birth
  • due to:
    • thrombosis in the lumen after ligating the umbilical cord
    • mechanical stimuli at birth
    • reduced oxygen tension through the vessel
• anatomical obliteration:
  • takes several months
  • due to fibrosis of the lumen by intimal proliferation

The only remnants of the umbilical arteries are fibrous cords in the adult; these are the medial umbilical ligaments which extend in the extra-peritoneal fat of the abdominal wall from the umbilicus to the superior vesical arteries. The latter remain patent.