Umbilical Cord

What is the umbilical cord?

The umbilical cord is a flexible, tubelike structure that acts as a lifeline between you and the fetus during pregnancy. It allows oxygen and nutrients to flow to the fetus and carries away waste products.

After your baby is born, they don’t need the umbilical cord. A healthcare provider will cut the umbilical cord, leaving a short piece of it behind on your baby’s tummy. This is called an umbilical cord stump. The stump will naturally dry up and fall off within a few weeks after birth. Your baby’s belly button (navel) remains in its place.

What is the function of the umbilical cord?

The placenta and umbilical cord work together to support fetal blood flow throughout your pregnancy. In a sense, the placenta functions as the fetus’s lungs, heart and gastrointestinal (GI) system during fetal development, and the umbilical cord connects the fetus to the placenta.

You can think of the umbilical cord as a road where traffic travels in both directions. In one direction, blood rich in oxygen and nutrients flows from the placenta to the fetus to allow the fetus to grow. In the other direction, blood low in oxygen and high in waste products (like carbon dioxide) flows from the fetus back to the placenta to be taken care of by the pregnant person’s body.

This two-way traffic continues throughout your pregnancy until your baby is born. After birth, your baby no longer needs the placenta and umbilical cord to provide nutrients and oxygen. Their own organ systems are ready to take over.

Where is the umbilical cord located?

The umbilical cord forms in your uterus during the first trimester of pregnancy. It connects the developing fetus to the placenta, which is a temporary organ attached to the wall of your uterus.

The cord typically attaches to the center of the placenta on one end and a fetus’s belly (at the spot that will later become their belly button) on the other end.

What does the umbilical cord look like?

The umbilical cord looks like a thick rope that has spirals, or coils, all down its length. These coils make the cord stronger and help keep it from getting squished as the fetus grows. A white, jelly-like connective tissue (Wharton’s jelly) surrounds and protects the umbilical cord.

How big is the umbilical cord?

A normal umbilical cord grows to be about 19.6 to 23.6 inches (50 to 60 centimeters) long by the end of your second trimester. Its thickness (diameter) is less than an inch (1 to 2 centimeters).

What are the umbilical cord vessels?

A typical umbilical cord contains three blood vessels:

• One umbilical vein, which transports oxygen-rich blood from the placenta to the fetus.
• Two umbilical arteries, which transport oxygen-poor blood from the fetus back to the placenta.

What conditions or abnormalities can affect the umbilical cord?

Issues with the umbilical cord risk decreasing blood flow to the fetus, which could cause problems with normal organ growth and development. Umbilical cord conditions or abnormalities that may arise during pregnancy include:

• Abnormal cord coiling: The umbilical cord may have too many coils (hypercoiled) or too few coils (hypocoiled). Possible causes include changes in blood flow or certain fetal movements. Abnormal coiling is sometimes associated with pregnancy complications.
• Marginal cord insertion: The umbilical cord attaches near the edges of the placenta rather than at its center.
• Nuchal cord: The umbilical cord loops around the fetus’s neck. Usually, this is harmless, especially if the loop is loose. But a tight loop can sometimes lead to complications during pregnancy or delivery.
• Single umbilical artery (two-vessel umbilical cord): The cord only has one artery (rather than two) and one vein. This can be a sign of a genetic condition like trisomy and is sometimes associated with structural changes to fetal organs like the heart.
• True knot: A tight knot forms in the umbilical cord. This may lead to complications like reduced blood flow to the fetus.
• Umbilical cord cysts: Sacs of fluid (cysts) can form in the umbilical cord. They’re often harmless. But it’s possible for a cyst to press on the cord and reduce blood flow.
• Umbilical cord prolapse: The umbilical cord drops into your cervix ahead of your baby. This is a medical emergency that typically requires a C-section.
• Vasa previa: Unprotected umbilical cord vessels travel across the opening of your cervix. The pressures of labor can cause the vessels to burst and heavily bleed. Early diagnosis and a C-section delivery can prevent serious complications or fetal death.
• Velamentous cord insertion: The umbilical cord doesn’t attach to the placenta as expected. Instead of reaching the inside of the placenta, the cord attaches to membranes outside the placenta. This can lead to slow fetal growth and other complications.

Many of these issues are rare, or they rarely cause serious complications. Your provider will keep a close eye on your pregnancy at your prenatal appointments. They see the umbilical cord on your ultrasounds and can typically notice if something isn’t right. They’ll let you know if you need further testing or monitoring due to an umbilical cord issue — or for any other reason.

What happens to my baby’s umbilical cord when they’re born?

After your baby is born, providers cut the umbilical cord to separate it from the placenta. This is because your baby is ready to breathe and eat on their own. So, they no longer need the cord. All that’s left on your baby’s belly is a small stump, which naturally falls off within a few weeks (revealing their belly button). Cutting the umbilical cord is simple, routine and doesn’t hurt your baby.

Does my baby have feeling in their umbilical cord?

No. The umbilical cord doesn’t have nerves, so your baby has no feeling in the cord. Your baby won’t feel pain when the provider cuts the cord. And your baby won’t feel any pain or discomfort as the cord stump dries, shrinks and falls off.

How do I take care of my newborn’s umbilical cord stump?

Your provider will tell you how to care for your baby’s umbilical cord stump when you return home. In general, it’s important to keep the cord stump clean and dry to prevent infection (omphalitis).

Here are some care tips:

• Do sponge baths until the stump falls off. This means using a soapy washcloth to clean your baby’s body rather than putting them into a tub of water. Allow the stump to air dry. Once the stump falls off, wait a couple of days and then do a real bath. 
• Fold the diaper down. When diapering your baby, fold the front of the diaper down below the cord stump and in toward your baby’s tummy. This helps keep poop and pee from reaching the stump. Some newborn diapers have a special cut-out cord area.
• Wipe clean as needed. If poop or pee gets onto the cord stump, use a damp cloth to wipe the area. Allow it to air dry.
• Wait for the stump to fall off. It’ll naturally do this on its own. Don’t try to pull off the stump, even if it seems like it’s dangling by a thread. Pulling off the cord stump may cause unnecessary bleeding and harm your baby.
• Watch for signs of infection. These may include redness, swelling, fluid discharge, foul smell or bleeding. Call your pediatrician right away if you suspect an infection.

Can I use alcohol for umbilical cord care?

It’s not a good idea to use alcohol on your baby’s umbilical cord area. In the past, new parents used rubbing alcohol to clean the umbilical cord after a bath or diaper change. Today, research shows this could destroy healthy bacteria that help the stump naturally fall off.

Instead of using alcohol, gently wash your baby’s umbilical cord stump with a damp sponge or washcloth and let it air dry.

When does the umbilical cord fall off? 

The umbilical cord stump typically dries up and falls off one to three weeks after birth. If it’s still attached at three weeks, contact your pediatrician as this may be a sign of an underlying medical condition.

As the stump dries, it shrinks and changes in color from yellowish-green to brown to black before falling off on its own. You can throw away the stump after it falls off.

Is it normal for my baby’s umbilical cord to fall off and the belly button to be yellow underneath?

If you notice any changes to your baby’s skin, call your pediatrician. It’s possible you’re seeing a common and harmless piece of scar tissue called an umbilical granuloma. This may form on your baby’s belly button after the cord stump falls off. A bit of light-yellow fluid may drain from the granuloma.

Normally, an umbilical granuloma will clear up in a week or so. If it’s still there after a week, your pediatrician can do simple, in-office treatments to get rid of it.

What should I do when my baby’s umbilical cord stump falls off?

Your baby’s belly button might bleed a little when the cord stump falls off. Light bleeding is normal. Gently wipe away the blood. If more blood appears each time you wipe, call your pediatrician.

You may also notice bleeding if your baby’s umbilical cord gets pulled off accidentally. The same advice applies: wipe the blood, but if there’s continued bleeding, seek medical care.

When should I contact a healthcare provider?

Call your pediatrician if your baby’s umbilical stump:

• Doesn’t fall off after three weeks.
• Leaks pus or fluid.
• Swells or the surrounding area looks red/discolored.
• Bleeds without stopping.

You should also call if your baby:

• Has a fever.
• Won’t feed normally.
• Seems overly sleepy or lethargic.
• Cries when you touch their umbilical cord stump or the skin around it.