Can a thin umbilical cord harm my baby?

Blood flow may be reduced if the cord is thin, but it is not always the case. Your doctor will suggest more ultrasounds or other options if they think they are necessary.

Is a thick umbilical cord a reason for early delivery?

A thick cord is normal, but your doctor may still want to monitor your case closely so that the blood flow is proper.

How often is cord thickness checked?

A cord thickness is usually measured during the second and third trimester routine ultrasound scans. You may need them more often if you have diabetes or high blood pressure.

Why the Umbilical Cord Thickens or Thins During Pregnancy

The umbilical cord appears as a flexible tube in the ultrasound that connects your baby to the placenta. However, this tube has a major role in your baby’s growth and is not just a connection. It transfers all the vital nutrients and oxygen to your baby in the womb to help them grow.

The thickness of the umbilical cord can change naturally throughout the pregnancy, but what causes this to happen? Understanding the reasons can help you know what it means for you and your baby. You will also know when to seek medical help if the thickness of the cord is out of the normal range.

What Is a Normal Umbilical Cord Thickness?

The normal diameter of the umbilical cord is around 1-2 centimetres, but the thickness may differ depending on what stage of pregnancy you are currently in.

The cord is thin but supplies the nutrients to your baby during the first trimester.
In the second trimester, the cord thickens due to increased blood flow as the baby grows faster.
In the third trimester, the cord reaches its maximum thickness to fulfil the higher needs for oxygen and nutrients in your baby.

Although these changes are natural, any unusual thickness or thinning of the cord may be a sign of a problem.

Why Does the Umbilical Cord Thicken?

The umbilical cord may become thick due to the following reasons, out of which some are normal, but others may need monitoring.

Excess Wharton’s jelly: It is a gel-like substance present in the cord to protect the blood vessels from damage. The cord appears thick in the scans if the jelly is in excess.
Diabetes: The cord can be thick if your sugar levels are higher than normal.
Multiple pregnancies: Twins or triplets can have a slightly thicker cord in some cases.
Infections or inflammation: Swelling due to infections may lead to a thicker cord.

Generally, a thick cord is harmless, but your doctor may suggest other scans to assess the blood flow in your baby.

Why Does the Umbilical Cord Thin?

It can be concerning if the umbilical cord is thinner than usual, but it is not always alarming.

Decreased Wharton’s jelly: If the gel in the cord is less, it will appear thin.
Placental insufficiency: The cord may not develop properly due to the poor functioning of the placenta.
Low blood flow: High blood pressure can also make your cord thinner.

The risk factors associated with a thin cord are high. Therefore, your doctor may suggest close monitoring and regular ultrasounds to see whether everything is normal.

How Is Umbilical Cord Thickness Measured?

Your doctor may check the thickness during the regular prenatal checkups. They check the following parameters of the cord.

Diameter of the cord at its widest point.
Amount of Wharton’s Jelly around the blood vessels.
Blood flow is assessed using Doppler ultrasound to determine if your baby is receiving enough oxygen.

These measurements are compared with the growth charts for your gestational age and help your doctor decide whether intervention is necessary.

What Are the Signs That You Should Be Concerned?

You may not feel anything unusual due to the cord thickness, but your doctor may advise monitoring in the following cases.

Ultrasound shows unusual cord thickness.
Your baby’s growth is slower than expected.
Decrease in fetal activity or their movement.
High-risk pregnancy conditions exist (diabetes, hypertension, twins).

Your baby’s activity is a critical sign of their health, so if you notice a sudden decrease in movement, contact your doctor immediately.

How Can You Support a Healthy Umbilical Cord?

You can focus on improving your overall health for pregnancy.

Eat foods dense in nutrients to help your placenta and baby grow properly.
Water supports blood flow, so drink at least 8 glasses daily.
Attend your prenatal checkups so that your doctor can detect any cord issues early.
Keep diabetes, blood pressure, or thyroid issues under control to prevent complications.
Gentle exercise, meditation, or support from your partner or family can improve overall well-being.

Emotional and Social Aspects to Consider

You may be surprised to know about the issue with the cord thickness if it is something you never anticipated. Most parents react the same way, so you are not alone. What you can do is share these updates with your partner for emotional support or discuss the concerns with your doctor.

What Should You Do Next?

The following points can guide you to take practical steps if you are worried about the cord thickness.

Get all scheduled ultrasounds.
Keep a daily note of fetal movements.
Discuss any medical conditions with your doctor.
Maintain a healthy lifestyle.
Reach out to your family or friends for emotional support.

The umbilical cord will change its thickness throughout the pregnancy as your baby’s needs change when they grow. Some of the variations do not cause any significant problems in your baby, but others may need close monitoring from your doctor. You can make informed choices by attending prenatal checkups and discussing the options with your doctor.

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FAQs on Why the Umbilical Cord Thickens or Thins During Pregnancy

Can a thin umbilical cord harm my baby?
Blood flow may be reduced if the cord is thin, but it is not always the case. Your doctor will suggest more ultrasounds or other options if they think they are necessary.
Is a thick umbilical cord a reason for early delivery?
A thick cord is normal, but your doctor may still want to monitor your case closely so that the blood flow is proper.
How often is cord thickness checked?
A cord thickness is usually measured during the second and third trimester routine ultrasound scans. You may need them more often if you have diabetes or high blood pressure.