Two Vessel Umbilical Cord, What Does That Mean?
From my clinical experience, most women are unaware that an umbilical cord is made up of three vessels. So when a mom-to-be is told that her umbilical cord has only two vessels, they aren’t sure what to do with the information. This blog will dive deeper into the anatomy of the umbilical cord and answer some common questions about two vessel umbilical cords.
The umbilical cord connects the mother’s placenta to an opening in the baby’s stomach. It is approximately 20 inches long and carries oxygen and nutrients from the placenta to the baby’s bloodstream). The umbilical cord is made up of one vein and two arteries. The vein carries oxygenated blood and nutrients from you to the baby, while the two arteries return deoxygenated blood and waste products to the placenta for removal (1).
When a woman has a two vessel umbilical cord, she will have one vein and one artery (see figure 1). This is also referred to as having a Single Umbilical Artery (SUA) (2). Typically, there are not any signs of having a two vessel cord before it is diagnosed via ultrasound. Approximately 0.3-1% of all pregnant women will have a two vessel cord (3). SUA is an isolated finding in over 80% of cases (3).
Figure 1: Umbilical Anatomy (4)
Research previously suggested that there may be an increase in congenital anomalies and perinatal morbidity with two vessel umbilical cords (3). However, recent literature states that there is no significant difference in neonatal outcomes when a SUA is found without other anomalies (3). It is important to be aware that the kidneys and heart develop at the same time as the umbilical cord in utero (2). Occasionally, there is a slight risk of abnormalities in these systems as a result (2). A notable abnormality seen in my practice is altered kidney location which was suspected in utero and confirmed following birth. Your doctor or midwife will likely involve a specialist to rule out any abnormalities if you are diagnosed with a SUA (2).
There is no treatment for a SUA, but your provider will continue to monitor your baby’s growth and organs regularly to rule out any red flags (2).
As always, be sure to discuss any and all concerns with your care provider on a regular basis.
Sarah Tirimacco, DC@birthfit_rochester_ny BIRTHFIT Rochester NY
- Chetty-John A, Zhang J, Chen Z, Albert P, Sun L, Klebanoff M, Grewal U. Long-term physical and neurologic development in newborn infants with isolated single umbilical artery. American Journal of Obstetrics and Gynecology. 2010 Oct; 203(4):368.e1-368.e7.