Velamentous Cord Insertion

What is velamentous cord insertion?

Velamentous cord insertion is a pregnancy complication that happens when the umbilical cord from a fetus doesn’t insert into the placenta correctly. The placenta is an organ in your uterus (womb) that forms during pregnancy. It allows your body to share nutrients with the fetus. The umbilical cord connects the fetus to the placenta so that the sharing can happen.

Typically, the umbilical cord travels from a fetus’s belly button to inside the placenta, where there’s easy access to the nutrients you’re sharing. A gel-like substance called Wharton’s jelly protects the blood vessels inside the umbilical cord so that they don’t twist, squeeze or break.

With velamentous cord insertion, the umbilical cord attaches to membranes outside of the placenta instead. This means that the blood vessels from the umbilical cord have to travel much farther to get nutrients from the placenta. And they have to travel without the protection of Wharton’s jelly. Without easy access to the placenta’s nutrients, a fetus may develop more slowly. Without the cushioning from Wharton’s jelly, the exposed blood vessels from the umbilical cord are more likely to burst and bleed.

How common is velamentous cord insertion?

Velamentous cord insertions are rare. Only about 1% of single-birth pregnancies (one baby) and 6% of multiple births (twins) involve velamentous cord insertion. The rate increases to about 15% for twins who share the same placenta (MCDA twins).

What causes velamentous cord insertion?

No one knows for sure what causes velamentous cord insertion. But they tend to show up more often in certain pregnancies. Understanding when they’re more likely to happen can make it easier for you and your healthcare provider to take all necessary precautions to keep you and the fetus safe during pregnancy.

• Pregnancies involving twins, especially twins that share a placenta.
• Pregnancies involving in vitro fertilization (IVF).
• Pregnancies involving a first-time birth parent.
• Pregnancies where the placenta attaches to the lower portion of the uterus, near your cervix (placenta previa).
• Pregnancies where unprotected blood vessels from the umbilical cord travel across your cervix (vasa previa).

Is velamentous cord insertion considered high risk?

Yes. Velamentous cord insertion can slow a fetus’s development. Without the protection of Wharton’s jelly, the blood vessels in the umbilical cord are more likely to break and bleed. These risks may affect your pregnancy and your baby.

With velamentous cord insertion there’s an increased risk of:

• Premature birth. Your baby may need to be delivered before the due date.
• Cesarean birth (C-section). Your healthcare provider may suggest a planned C-section before your due date. You may have to have an emergency C-section during labor if there’s heavy bleeding.
• Placental abruption. The placenta may separate from the wall of your uterus.
• Preeclampsia. Your blood pressure may rise after 20 weeks of your pregnancy.

Your baby may:

• Be underweight or look smaller when compared to other newborns.
• Need special care in a neonatal ICU unit.
• Have low apgar scores. Apgar tests happen within the first five minutes after your baby is born. Your healthcare provider will check your baby’s breathing, heart rate, muscle tone, reflexes and skin color to assign a score from zero to 10. A low score means that your baby may need additional help breathing and adjusting to life outside of your body.

What are velamentous cord insertion complications?

About 6% of pregnancies with velamentous cord insertion also have a condition called vasa previa. With vasa previa, the umbilical cord attaches to membranes that are close to your cervix. During labor, the exposed blood vessels run an especially high risk of bursting when the fetus starts putting pressure on your cervix. Both you and the fetus run the risk of heavy bleeding. About half of these pregnancies end with stillbirth.

Getting diagnosed early can prevent this from happening. If your healthcare provider sees exposed blood vessels from the umbilical cord near your cervix, they’ll likely suggest a C-section. The outcomes associated with vasa previa improve greatly with a C-section. The survival rate for the fetus goes up to 97% to 99%.

What are the symptoms of velamentous cord insertion?

Vaginal bleeding — especially in your third trimester — can be a sign of velamentous cord insertion. Or, you may not notice any symptoms at all. Instead, your healthcare provider will likely be able to diagnose velamentous cord insertion through imaging and by monitoring the fetus. The fetus may have:

• A slow heart rate.
• Reduced blood supply.

How is velamentous cord insertion diagnosed?

By your second trimester, your healthcare provider should be able use an ultrasound to see where the umbilical cord has inserted. A color Doppler ultrasound provides an even clearer picture. By your third trimester, when the fetus has grown much bigger, it may be harder for your provider to see the umbilical cord and make a diagnosis.

How is velamentous cord insertion treated?

There’s no way to treat velamentous cord insertion. Instead, your healthcare provider will take extra precautions to reduce any risks. Your provider may:

• Monitor the fetus’s growth every 4 to 6 weeks.
• Do regular non-stress tests on the fetus. A non-stress test monitors the fetus’s heart rate and movement. This kind of test is perfectly safe for both you and the fetus.
• Admit you to the hospital once it becomes closer to your delivery time.
• Schedule a C-section around week 34 if there’s concern that blood vessels could burst and cause severe bleeding, as with vasa previa.
• Induce delivery at week 40 if you’re delivering the baby vaginally. Around this time, the fluid to support pregnancy lessens and may put more pressure on the blood vessels.
• Take extra care to monitor your baby’s vitals during labor to ensure that it’s delivered safely.

How can I prevent velamentous cord insertion?

You can’t prevent velamentous cord insertion, but your chances of experiencing one are extremely low. If you’ve been diagnosed with velamentous cord insertion, this means that your healthcare provider knows to monitor your pregnancy closely for any complications. Early diagnosis and close monitoring make all the difference when it comes to having a healthy pregnancy.

What can I expect if I have velamentous cord insertion?

Your provider will take extra care to monitor your pregnancy so that you’re able to deliver your baby safely. This may mean regular ultrasounds and non-stress tests. It may mean that you deliver your baby via a C-section or vaginally. Your provider may recommend that you deliver around your due date or several weeks before. It may mean that your baby needs additional care in the neonatal ICU unit once it arrives.

Your healthcare provider is the best resource to advise you on the most appropriate plan for your pregnancy and what to expect in the days leading up to delivery and after your baby is born.

What should I do if I have velamentous cord insertion?

Speak with your healthcare provider to understand what velamentous cord insertion means for your pregnancy. The treatment you receive will depend on your unique case. Follow your provider’s instructions for how to best care for yourself each day. Questions to ask include:

• How much daily activity do you recommend?
• What kinds of exercise can I safely do?
• Are there activities I should avoid?
• What kinds of foods should I be eating?
• How much should I be resting each day?
• How many hours of sleep should I be getting each night?

A note from Cleveland Clinic

Learning about the complications that can happen with velamentous cord insertion can be scary. But complications are rare. You may need closer monitoring both during your pregnancy and during labor, but this extra care improves the outcomes in velamentous cord insertion pregnancies. Speak to your healthcare provider about how your velamentous cord insertion will influence your pregnancy plan.