Introduction
Velamentous cord insertion is an abnormal cord insertion where there is a divergence of umbilical vessels as they transverse between the amnion and chorion before they reach the placenta. This can lead to complications in pregnancy. There are membranous umbilical vessels at the placental insertion site, where the remainder of the cord is usually normal. The velamentous cord insertion will be monitored closely by the healthcare provider, who will recommend a plan for the pregnancy to reduce the risks during childbirth.
What Is Velamentous Cord Insertion?
Velamentous cord insertion is a complication seen during pregnancy due to the umbilical cord from a fetus not inserting into the placenta completely. The placenta is an organ that is present in the uterus and is formed during pregnancy. It will allow the body to share nutrients with the fetus. Sharing happens when the umbilical cord connects the fetus to the placenta.
Normally, the umbilical cord travels inside the placenta from the fetus's belly button, and there is easy access to the nutrients to share.
The blood vessels inside the umbilical cord are protected by a gel-like substance known as Wharton's jelly, so they do not squeeze, twist, or break. The umbilical cord is attached to the membrane outside the placenta with velamentous cord insertion. To get the nutrients from the placenta, the blood vessels from the umbilical cord must travel much farther, and there will not be any protection from Wharton’s jelly. Due to this reason, there will be slow development of the fetus, and since there is no protection against Wharton’s jelly, the blood vessels might burst and bleed.
What Are the Causes of Velamentous Cord Insertion?
The exact cause of velamentous cord insertion is not known, but they are often seen in certain pregnancies such as:
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Twin pregnancies, especially when the twins share the placenta.
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Pregnancies that involve a first-time birth parent.
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Pregnancies that involve in vitro fertilization.
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In pregnancies, the placenta is the lower portion of the uterus near the cervix.
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Pregnancies where the blood vessels from the umbilical cord are not protected travel across the cervix.
What Are the Risk Factors of Velamentous Cord Insertion?
The fetus’s development can be slowed down due to velamentous cord insertion. As there is no protection from Wharton’s jelly, the blood vessels in the umbilical cord might break and bleed. These risks might affect the pregnancy and the baby.
The risk factors for velamentous cord insertion are:
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There is premature birth of the baby as there is a need to deliver before the due date.
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If there is heavy bleeding, healthcare providers might suggest an emergency cesarean birth (C-section) before the due date.
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The placenta might separate from the uterus wall known as a placental abruption.
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There might be a rise in blood pressure, known as preeclampsia, after twenty weeks of pregnancy.
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Babies might be underweight when compared to newborns and might need special care in a neonatal intensive care unit.
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Babies might have low Apgar scores. This test usually happens within the first five minutes after the baby is born. The healthcare provider will check the baby's heart rate, breathing, muscle tone, reflexes, and skin color to assign a score from zero to ten. Additional breathing help might be required for the baby when the score is low.
What Are the Complications of Velamentous Cord Insertion?
A condition called vasa previa is present in 6% of pregnancies with velamentous cord insertion. In this condition, the umbilical cord will attach to the membrane close to the cervix. The fetus might put pressure on the cervix during labor, and therefore, the exposed blood vessels are at high risk of bursting. The fetus and the mother are at high risk of heavy bleeding. Half of these pregnancies end with stillbirth. This can be prevented from happening by getting diagnosed early. The healthcare provider suggests a C-section if they see exposed blood vessels from the umbilical cord near the cervix. With a C-section, the outcomes associated with vasa previa will improve, and the survival rate of the fetus is 97% to 99%.
What Are the Symptoms of Velamentous Cord Insertion?
The sign of velamentous cord insertion during the third trimester is vaginal bleeding, and sometimes there may be no symptoms at all. Instead, the healthcare provider can diagnose velamentous cord insertion through imaging and monitoring the fetus. The fetus might have a slow heart rate and a reduced blood supply.
How Is Velamentous Cord Insertion Diagnosed?
With the help of ultrasound, the healthcare provider can see where the umbilical cord is inserted during the second trimester. A color Doppler ultrasound provides an even clearer picture. When the fetus has grown much bigger in the third trimester, it might be difficult for the provider to see the umbilical cord and make a diagnosis.
Can Velamentous Cord Insertion Be Treated?
Velamentous cord insertion cannot be treated; the healthcare provider takes extra precautions to reduce risks. Healthcare providers might:
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Every four to six weeks, monitor fetus growth.
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Regularly, non-stress tests are done on the fetus to monitor the heart rate and movement. This test is safe for both the mother and fetus.
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Admission is done to the hospital once it becomes closer to delivery time.
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Around thirty-four weeks, a C-section is scheduled if there is a chance of blood vessels bursting and causing severe bleeding.
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If the baby is to be delivered vaginally, delivery is induced at forty weeks, as around this time, the fluid to support pregnancy lessens and may put more pressure on the blood vessels.
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Extra care should be taken during labor to monitor the baby's vitals to ensure it’s delivered safely.
Can Velamentous Cord Insertion Be Prevented?
Velamentous cord insertion cannot be prevented, but the chances of experiencing one are extremely low. Once the individual is diagnosed with velamentous cord insertion, the healthcare provider will monitor the pregnancy closely for any complications. Early diagnosis and close monitoring are essential for a healthy pregnancy.
Conclusion
Velamentous cord insertion, detected prenatally, will reduce the number of emergency cesarean sections in low-risk women and also reduce fetal and neonatal morbidity and mortality. Technologies are available to diagnose abnormal cord insertions, and they should be carefully utilized by doctors to monitor and prevent dangerous situations from arising during childbirth.
