What Is Umbilical Cord Compression?

Umbilical cord compression happens when the umbilical cord, the tube-like structure that connects the placenta to the fetus, becomes compressed or flattened, restricting the flow of blood, oxygen, and nutrients to the baby.

Mild or temporary compression is fairly common and is caused by the baby's movement in the womb or contractions during labor. This type of compression usually resolves after a short time without complication.

Severe umbilical cord compression that happens for a longer period of time can cut off oxygen and blood flow to the baby, often requiring an emergency cesarean delivery (or C-section), and potentially causing serious, rare complications like brain damage.

Causes

There are several different scenarios that have the potential to cause umbilical cord compression, including:

• Baby's positioning or movement: Sometimes the umbilical cord can be squeezed or compressed as a result of the fetus's hyperactivity in the womb, particularly during the later stages of pregnancy.
• Uterine contractions: The normal compression and squeezing from contractions during labor can flatten or press against the umbilical cord.
• Umbilical cord prolapse: Prior to delivery, it's possible (though rare) for the umbilical cord to drop through the birth canal before the baby does, causing cord compression.
• Nuchal cord: It's estimated that in up to 29% of pregnancies, the umbilical cord becomes wrapped around the baby's neck, which can cause mild compression. Serious compression can happen but is rare.
• Knotted cord: The umbilical cord can become knotted, particularly if it's abnormally long and compressed. If the knots are loose, it's usually not a serious issue. If the knots are too tight, they can cut off the flow of oxygen to the fetus.

Signs

It's possible to discover umbilical cord compression during routine pregnancy screenings, but it is sometimes not discovered until delivery or birth.

There usually are not any obvious or noticeable signs of umbilical cord compression for the pregnant person, though some people experience:

• Less activity or a decrease in movement from the fetus
• Increased activity or movement from the fetus (which can actually help reposition and relieve the compression)
• The umbilical cord dropping into the birth canal (if the cord prolapses)

There are also some clues that your doctor will look for if they suspect umbilical cord compression, which can be diagnosed by fetal doppler, ultrasound, or pelvic exam.

Your care team will monitor for:

• Change in the baby's heartbeat: An abnormally slow or abnormally fast heart rate could indicate that the baby is not receiving enough oxygen or is in distress.
• Abnormal levels of amniotic fluid: Too little amniotic fluid (oligohydramnios) may increase the likelihood of umbilical cord compression due to not enough fluid being available to cushion the umbilical cord.
• Intrauterine growth restriction (IUGR): A size deficiency could mean that the baby did not receive enough nutrition to grow at a normal rate, potentially because there was cord compression.

Treatment

Once umbilical cord compression has been identified, your doctor will want to treat it quickly to avoid complications.

Appropriate treatment for umbilical cord compression depends on a few factors: the underlying cause, the baby's current health condition or status, and the likelihood of the baby's health deteriorating.

For mild cases of compression (where the baby does not appear to be in serious or life-threatening distress), your doctor may suggest:

• Switching positions: Sometimes changing your position (from lying on your right to your left side, for example) can help alleviate compression and get more blood flowing to the baby.
• Oxygen administration: Receiving supplemental oxygen may help regulate the baby’s heart rate and prevent further compression.
• Intravenous (IV) fluids: Administering hydration through an IV may help push more nutrients through to the baby if the flow has been slowed by compression.

In more severe situations where there are signs that the baby is in or will be in distress, treatment options might need to be more aggressive.

• Amnioinfusion: If the level of amniotic fluid (the liquid that "cushions" a fetus) is low, an amnioinfusion procedure involves inserting saline solution into the uterus to relieve the pressure that can cause cord compression.
• Medications to stop contractions: If a doctor feels that the infant is stable but needs additional time to recover before delivery, medication can be used to stop labor.
• C-section delivery: If the baby's heart rate has decreased dramatically or there are other serious signs that the baby is in distress, an emergency surgery to deliver the baby can be performed.

Risk Factors

It's not possible to predict if and when umbilical cord compression will happen. It's also not easy to tell if it will be a serious case with complications or just a mild, temporary condition.

There are a few risk factors that may increase the chance of umbilical cord compression occurring.

• A breech delivery
• A premature delivery
• Too much or too little amniotic fluid
• A multiples pregnancy (such as twins or triplets)
• An unusually long umbilical cord
• Giving birth at a later age

Complications

Any abnormality or problem involving the umbilical cord that is not quickly treated or resolved on its own has the potential to cause complications. Immediately after birth, your doctor and healthcare team will check the baby's vital signs and overall health, providing supplemental oxygen and other emergency care if needed, to make sure there are not any problems.

If the umbilical cord compression is severe enough to cut off the flow of oxygen to the baby—even for a brief period—it can cause permanent damage.

Potential complications include:

• Brain damage causing cerebral palsy
• Birth injuries associated with emergency C-sections, such as breathing difficulties or injuries or lacerations during the surgery
• In very rare cases, stillbirth or death

Frequently Asked Questions

What are the signs of umbilical cord compression?

Often, there are no noticeable signs for mild, temporary cases of umbilical cord compression that resolve on their own.

Signs of a more serious case of umbilical cord compression will typically indicate that the baby is in distress.

Signs of distress can include increased or decreased movement in the womb, an abnormally fast or abnormally slow heart rate, feeling the umbilical cord physically drop into the cervix, and a measurable size deficiency in the baby based on the average size of a fetus during pregnancy.

How common is umbilical cord compression?

Some estimates have stated that umbilical cord compression happens in roughly 1 out of 10 pregnancies. Many times, the condition either resolves itself or resolves with a doctor's quick intervention. Other cases can lead to a dangerous lack of oxygen to the baby and require an emergency C-section.

A Word From Verywell

Learning that your baby's umbilical cord is compressed is a frightening and stressful experience. However, remember that your doctor is trained to handle these situations and, in most cases, you will be able to deliver your baby safely.

Getting routine prenatal care that includes careful monitoring of fetal development and positioning is one way to make sure cord compression is caught early and addressed.

If you have any concerns about your risk for experiencing umbilical cord compression, make sure to bring these up with your doctor. They will be able to help answer your questions as you navigate the pregnancy and delivery experience.