Unlocking the Mysteries of Umbilical Cord Knots: Causes, Effects, and Treatment Insights

An umbilical cord is a conduit between the mother and her baby, through which the growing baby inside the mother’s womb receives blood, oxygen, and nutrition from the mother. During pregnancy, everyone eagerly waits for the birth of your baby. However, sometimes there might be concerns that come up during ultrasounds that would leave anyone with doubts and worries. One of the concerns could be the occurrence of umbilical cord knots. Although umbilical cord knots occur rarely in pregnancies, this complication can leave anyone feeling agitated.

This article will help you learn more about this rare complication of pregnancy or delivery, known as umbilical cord knots. Read further to know the symptoms, causes, and treatments available for umbilical cord knots.

The umbilical cord attaches to the placenta, an organ that develops during pregnancy through which blood, oxygen, and nutrition from the mother are transferred to the baby.

The umbilical cord of a baby has three layers of muscle:

1. Tunica Externa: It is the outer layer of the umbilical cord and is elastic and dense to protect the cord from damage.
2. Tunica Media: The middle layer of the umbilical cord that contains the majority of the blood vessels is called Tunica media. This layer of muscle helps in regulating your baby’s blood flow and blood pressure.
3. Tunica Interna: It is the center of the umbilical cord and is composed of connective tissue. Tunica interna contains valves that control the flow of blood to ensure deoxygenated blood goes into the placenta while oxygenated blood gets into your baby.

An umbilical cord knot is a rare complication of pregnancy or delivery when there appears a knot in the baby’s umbilical cord. In most cases, although the baby is born healthy, but sometimes complications like stillbirth and brain damage are also possible. A knot in the umbilical cord can cut off much-needed nutrients from reaching your baby, and this can stunt their growth and cause other health problems.

Some knots in the umbilical cord are formed during pregnancy, as the baby flips and turns in her amniotic sac; while other umbilical cord knots are formed during delivery or childbirth.

The important blood vessels of the umbilical cord are cushioned and protected by a substance called Wharton’s jelly. This substance protects these blood vessels even if the umbilical cord gets knotted. This sums up that a true knot won’t happen.

As long as the knot remains loose, it won’t cause any harm to the baby. However, if it becomes tight, it could interfere with the blood circulation from the placenta to your baby and lead to oxygen deprivation. Although cases are rare, such a complication can occur during your baby’s descent through the birth canal. ⁽¹⁾

Umbilical cord knots are not very common and occur in about one in every hundred cases of pregnancy. ⁽²⁾ Nuchal loops are more common than umbilical cord knots. Nuchal loops is the technical term used for the condition when the umbilical cord wraps around the baby’s neck. They are also known as nuchal cords, and appear in about 20% of all pregnancies, but rarely cause any harm to the baby. ⁽³⁾

Most umbilical cord knots do not show up on ultrasound imaging. However, as the technician monitors the heart rate and activity of your baby, they can check for signs of an umbilical cord knot. Even if visually the knots cannot be seen, the technicians can detect other signs of a problem with the flow of blood to and from the placenta. For instance, it could be a sign of an umbilical cord knot if your baby’s heart rate is pretty low and inconsistent.

Additionally, the baby having an umbilical cord knot might be less active than normal. This occurs because the nutrient supply is cut off due to the occurrence of the cord knot.

Nothing can be done to prevent an umbilical cord knot. However, keep a watch on how your baby is doing, especially around the 37^th week of your pregnancy, by doing regular kick counts and consulting with your doctor if you notice any change in fetal activity.

True umbilical cord knots can cause serious complications in the baby because they cut off the fetus’s oxygen supply. A tight umbilical cord knot can result in severe hypoxia or become fatal to the fetus. However, a looser cord knot might cause mild hypoxia and not cause any long-term damage.

Cerebral palsy, brain damage, Hypoxic-ischemic encephalopathy (HIE), and cognitive or developmental delays could be some of the long-term effects of true umbilical cord knots. One more serious complication of a true umbilical cord knot could be a stillbirth.

The exact cause of an umbilical cord knot is still unknown. Some umbilical cord knots appear naturally and you or your baby might have no known risk factors. However, the following factors can contribute to the chances of developing a true umbilical cord knot.

• If the baby has an extremely long umbilical cord.
• The fetus is very small for its gestational age.
• If you are carrying monoamniotic twins, which are identical twins sharing one amniotic sac.
• If you have too much amniotic fluid.
• In case you feel the fetus move less.
• In case you are above 35 years of age.
• If you have had two or more pregnancies.

Doctors cannot treat true umbilical cord knots by loosening them. The best way to manage a true cord knot is to be aware of the risk factors and watch for complications if the pregnant woman has any risk factors.

Doctors who notice an umbilical cord knot on an ultrasound before delivery should closely monitor your pregnancy, especially in the third trimester. They might perform additional ultrasounds, Doppler studies, and assessments of fetal growth and fetal activity.

However, if an umbilical cord knot is detected during delivery because of changes in fetal heart rate, your healthcare provider will have to monitor the fetus closely and watch for fetal distress. As your labor progresses, your doctor needs to watch the heart rate of your fetus, and if the fetus appears to be in distress or without oxygen, an emergency C-section would be required.

True umbilical cord knots rarely occur. While these cord knots can lead to several complications, they usually do not cause severe harm to the baby, and most babies are born quite healthy. However, if you experience low fetal activity during your pregnancy, talk to your doctor immediately.

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Also Read:

• Umbilical Cord Infection and Care
• Umbilical Cord Varix: Causes, Symptoms, Treatment, Complications, Prognosis, Prevention
• Short Umbilical Cord: Causes, Symptoms, Risk Factors, Treatment, Complications, Prevention, Prognosis