True Knot in Baby’s Umbilical Cord during Pregnancy

A pregnant mother holding her ultrasound scan

A knot in a baby’s umbilical cord is called a “True Knot of Umbilical Cord.” It can be caused by high levels amniotic fluid in the womb. It could also happen when the baby inadvertently experiences cord entanglement while being active. While in most cases, there doesn’t seem to be any complications during birth, there are risks involved. A knot of the umbilical cord sometimes changes the heart rate of the baby and may result in brain damage and stillbirths if the knot tightens during labour.

What is True Knot of Umbilical Cord?

The umbilical cord connects a growing foetus to the mother, providing the baby with blood rich in oxygen and nutrients. It resembles a cord and consists of two arteries and one vein which are protected and held together by a substance called Wharton’s Jelly. When this umbilical cord forms a knot, it is called a True Knot of Umbilical Cord.

Other Names For This Condition

Here are some other names by which this condition goes by:

  • Cord Knots in Pregnancy
  • Placental Knots
  • Umbilical Cord Knots

How Common is it during Pregnancy?

A pregnant mother holding her ultrasound scan

True Knots of Umbilical Cord are surprisingly common during pregnancies, usually occurring in one every 100 pregnancies. However, the true knot in umbilical cord fatality rate is low with only one in every 2,000 births causing complications. In cases of twins sharing the same amniotic sac in the uterus, chances of true knots forming are generally higher as there are two cords within the same sac.


Here are some factors that cause True Knots of Umbilical Cord:

  • Elevated foetal activity in the womb increases the chances of your baby getting entangled in the umbilical cord.
  • Long umbilical cords can wrap around the baby forming a knot
  • Babies that are relatively small have a high chance of getting entangled in the umbilical cord
  • Too much amniotic fluid in the sac allows for lots of movement of the foetus


Decreased foetal activity after the 37th week of pregnancy is often an indicator of this condition. This takes place as the blood circulation to the foetus is compromised, the degree varies according to how tight the knot is, thereby compromising the flow of oxygen and nutrients to the child.

Diagnosis Of Placental Knot

These are the modules used when diagnosing this condition:

  • Abnormal or decreased heart rate of the foetus.
  • Ultrasound exams to detect and assess the seriousness of the knot.
  • Colour Doppler Sonogram, used to check for problems with blood flow.
  • Examination of the cord during delivery.

Risk Factors

Some people are at greater risk of having knot formations in the uterus. These include:

  • Older women
  • Carrying two or more children at once (twins, triplets etc.) or having had multiple pregnancies
  • Long umbilical cord
  • Excess of amniotic fluids
  • Anaemia
  • Gestational Diabetes


There is no special treatment for this condition. It is best to:

  • Keep a general eye on your baby’s development.
  • If a diagnosed knot is tight, your doctor will generally suggest a C-Section delivery to reduce the chances of the knot tightening even further during delivery.

True Knot Of Umbilical Cord Complications

Some complications involved with a baby born with knot in umbilical cord include:

  • Negative changes in the heart rate of the foetus.
  • Brain damage.
  • Death of the foetus or stillbirth.


Some of the outcomes that go with this condition are:

  • High chance of survival with care and management.
  • Possible chance of brain damage.
  • The mortality rate of around 10%.

Difference Between True Knot And False Knot

A False Knot is simply an excess covering of Wharton’s Jelly, which makes it look very similar to a True Knot. False Knots never endanger the foetus whereas True Knots might.


Studies have shown that detecting knot formation is difficult to observe even with an ultrasound. This is because they have no characteristic patterns associated with them. However, sudden distress in the baby due to lack of proper oxygen and nutrients. They are:

  • Perform ultrasounds on a regular basis during pregnancy.
  • If diagnosed, close monitoring is required for the rest of the gestation period.

Knot formation of the umbilical cord is a dangerous phenomenon as it could lead to the blockage of oxygen and nutrients. Despite advances in modern medicine, medical professionals are yet to find a reliable way of detecting the complication. Thankfully, true knot formation is something that is rare and medical institutions have reliable systems to ensure the survival of the baby.

Also Read: How To Care Your Newborn’s Umbilical Cord?