What Is an Umbilical Cord?

baby in hospital with clamp on umbilical cord

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Your baby’s umbilical cord is a tube-like structure that connects your baby to you via your placenta. The umbilical cord carries nutrients and oxygen from your placenta into your baby’s body, and then carries waste material out.

The umbilical cord has two arteries and one vein.

  • The vein’s job is to transport oxygen and nutrients from your placenta, to your baby.
  • The arteries are responsible for transporting your baby’s waste material, which are eventually disposed of through your kidneys.
  • The umbilical cord’s arteries and veins are surrounded by a gelatin-like substance called Wharton’s jelly, which cushions and protects the veins and arteries.

Umbilical Cord Abnormalities

For the most part, umbilical cords do not have issues, and do a great job of keeping your baby healthy during pregnancy.

Occasionally, there are abnormalities in umbilical cords that can affect your baby’s fetal development or can cause complications during labor and delivery. Usually these abnormalities are found during routine ultrasounds, but sometimes they present during labor and delivery.

The following are the most common umbilical cord abnormalities.

Umbilical Cord Prolapse

In this condition, the umbilical cord drops into the space between your baby’s body and the cervix prior to delivery. This may happen before birth or during labor. Though rare (the condition usually occurs in one out of every 300 births), umbilical prolapse is an emergency and requires C-section delivery.

Single Umbilical Artery

Sometimes umbilical cords have one artery, rather than two. This is a rare condition and doesn’t usually present with other complications. However, having a single umbilical artery might increase your baby’s chances of having a congenital abnormality of the heart, kidneys, intestines, or skeleton.

Nuchal Cord

Nuchal cords, where your baby’s umbilical cord is wrapped around their neck at birth, are actually quite common. Sometimes the cord is wrapped around other parts of your baby’s body, or appendages.

Usually, nuchal cords do not present any problems to babies or mothers. Sometimes, the pressure of the wrapped cord causes heart rate abnormalities for your baby; in rare cases, this would necessitate a C-section.

Vasa Previa

Vasa previa is a very serious condition that can have dire consequences if not caught early. In this condition, one or more of the blood vessels of your baby’s umbilical cord begin to grow near your cervix.

Pressure from your baby’s body, or from childbirth, can cause the blood vessels to tear or become compromised, depriving your baby of oxygen. If not caught early enough, vasa previa can cause stillbirth; however, if caught before your baby is born, your baby can be born via C-section, and has a higher chance of survival.

Short Umbilical Cord

It’s normal for umbilical cords to vary in length. But a very short umbilical cord (less than 40 centimeters) can be a problem. It can lead to a premature separation of your baby from their placenta, which can lead to stillbirth.

Umbilical Cord Knots

Sometimes your baby’s umbilical cord may become knotted. If the knots are loose, this may not be a problem. But if the knots are tight, they can cut off circulation for your baby and deprive them of oxygen. Your baby may have an abnormal heart rate as a result and may require a C-section delivery.

Umbilical Cord Cysts

Umbilical cord cysts occur in about 3.4% of pregnancies. In and of themselves, they are usually not an issue. But they are known to occur with other congenital abnormalities such as trisomies of chromosomes (13 and 18), angiomyxoma of the cord, and imperforate anus.

If cysts are discovered during your ultrasound, your provider may want to perform other diagnostic tests to rule out other genetic abnormalities.

How To Care For Your Baby’s Umbilical Cord

Once you bring your new baby home, you will be tasked with caring for their umbilical cord stump as it heals. Many parents feel anxious about making sure they care for their cord correctly, and want to ensure that it heals perfectly. But the truth is, there isn’t that much you need to do to properly care for your baby’s cord—in fact, less is more in many cases.

Here’s what to know:

  • Experts no longer recommend cleaning the cord stump with alcohol
  • Keep your baby’s healing cord area dry
  • Fold your baby’s diaper down and allow the cord stump time to air out
  • Give your baby sponge baths until the stump has fallen off
  • When your baby’s cord falls off, you may notice a few drops of blood—this is normal
  • If your baby’s stump is bleeding heavily, call your doctor immediately
  • Most cord stumps will fall off with one to two weeks; contact your doctor if your baby’s cord hasn’t fallen off after six weeks

How To Know If There Is A Problem With Your Baby’s Umbilical Cord

Most umbilical cord areas heal with no issues, especially if you keep the area dry and allow it time to air out. But sometimes complications occur. Here’s when you’d want to contact your doctor about your baby’s umbilical cord:

  • If your baby’s umbilical cord is bleeding actively
  • If your baby’s cord hasn’t fallen off after two months

In rare cases, your baby’s umbilical cord may become infected. Signs of infection include:

  • If there is yellow discharge coming out of the cord
  • If the discharge has a smell
  • If you the skin around the cord has reddened
  • If your baby cries when their cord area, or the skin around it, is touched

If you notice any of these signs, call your doctor promptly so that the infection can be treated and so that it doesn’t spread.

In addition, there are two other conditions that may happen as your baby’s umbilical cord heals:

Umbilical Granuloma

Umbilical granulomas occur after the cord falls off. They look like small red scar tissue in the belly button area, and may include a light yellow discharge. In most cases, umbilical granulomas resolve on their own; if your baby’s umbilical granuloma doesn't go away in a week, contact your pediatrician.

Umbilical Hernia

Sometimes your baby’s belly button seems to protrude when they cry or exert themselves. This may indicate an umbilical hernia. This condition usually resolves by the time your baby is 12 or 18 months. If it doesn’t resolve, it may require surgery.

A Word From Verywell

Gestating and birthing babies can be a fascinating process, and your baby’s umbilical cord is no exception. Umbilical cords do the miraculous job of connecting you to your baby in the womb, and helping them grow and thrive. Thankfully, most abnormalities of the umbilical cord are rare; and if something goes wrong, this can usually be detected by a pregnancy ultrasound. Still, it’s good to be informed about what can go wrong, and what questions you might want to ask your doctor about any umbilical cord abnormalities.

Like umbilical cord abnormalities, it’s rare for any complication to happen as your baby’s umbilical cord stump heals. Again, it’s always better to be safe than sorry, so don’t hesitate to reach out to your baby’s pediatrician if you have any questions about your baby’s umbilical cord care.

Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Basta M, Lipsett B. Anatomy, Abdomen and Pelvis, Umbilical Cord. Treasure Island, FL:StatPearls;2020.

  • Mayo Clinic Staff. Umbilical cord care: Do's and don'ts for parents. Mayo Clinic website. Updated February 7, 2020.

  • Umbilical Cord Care. Healthy Children website. Updated March 3, 2020.

  • Umbilical Cord Prolapse. Cleveland Clinic website. Updated September 9, 2020.

By Wendy Wisner
Wendy Wisner is a lactation consultant and writer covering maternal/child health, parenting, general health and wellness, and mental health. She has worked with breastfeeding parents for over a decade, and is a mom to two boys.