Vasa Previa Definition, Reason, Symptoms, Treatment & Prevention

Vasa Previa Definition, Reason, Symptoms, Treatment & Prevention


Vasa previa is a complication of pregnancy that is characterized by the presence of blood vessels from the fetal umbilical cord that cross the mouth of the uterus (cervix).

Under normal circumstances, all the blood vessels of the fetus are wrapped and protected in the umbilical cord. But in vasa previa, there are fetal blood vessels that come out of the umbilical cord and cross the cervix along with the amniotic membranes.

Disturbances in vasa previa can occur during pregnancy or during childbirth. As the fetus gets bigger and its head descends towards the mother’s vagina, the abnormal blood vessels belonging to the fetus that cross the mouth of the mother’s womb will be pressed against the fetal head itself. 

This causes the fetus to lack blood flow, lack of oxygen and can lead to death.

Vasa Previa Symptoms

In most cases, pregnant women who experience vasa previa do not experience any symptoms during pregnancy. New symptoms appear during the delivery process, in the form of an abnormal fetal heart rate due to lack of oxygen. 

If labor is not carried out quickly, often the baby is born dead.

But sometimes, vasa previa can also cause symptoms since pregnancy. Symptoms include bleeding from the vagina. 

Usually, the blood that comes out is dark red or black. These complaints are followed by fetal movements that are getting less and less, in fact there is no movement at all.

Vasa Previa Reason

There are two main causes of vasa previa, namely:

  • Velamentous cord insertion, which is an abnormality in the umbilical cord that causes the blood vessels that should be in the umbilical cord to come out and attach to the amniotic membranes.
  • Bilobus placenta (bilobed placenta), namely the presence of two placentas in the uterus even though there is only one fetus.

Pregnant women who are more prone to experiencing vasa previa are pregnant women with the following conditions:

  • Placenta previa (where the placenta is covering the birth canal)
  • Low-lying placenta (the placenta is close to the birth canal)
  • Pregnancy occurs through the process of IVF
  • Twin pregnancy
  • Have a history of surgery in the uterine area before


Determination of the diagnosis of vasa previa is carried out by an obstetrician through an ultrasound examination (USG). Ultrasound that is done to see whether there is a vasa previa is a transvaginal Doppler ultrasound, which is a Doppler ultrasound to see a picture of the blood vessels where the tool ( probe ) is inserted through the vagina.

Vasa Previa Treatment

Vascular abnormalities that occur in vasa previa cannot be treated or eliminated because they are anatomical abnormalities. 

Therefore, the goal of vasa previa treatment is not to normalize the fetal blood vessels, but to provide special treatment so that the fetus can be born alive in optimal conditions.

In the first and second trimesters of pregnancy, there is no specific treatment for vasa previa. Even in some cases, vasa previa which is known in the early trimester can disappear by itself. 

Special treatment is carried out in the third trimester (pregnancy 28 weeks and above), can be in the form of:

  • Closer monitoring of the condition of the fetus through physical examination and Doppler ultrasound.
  • Giving corticosteroid drugs to ‘mature’ the fetal lungs to prepare the fetal lungs to function properly if they have to be born prematurely.
  • Pregnant women should not insert anything into the vagina, and it is recommended not to have sex before giving birth.

In a vasa previa pregnancy, delivery is planned through a Caesarean section. In contrast to deliveries in normal pregnancies which are carried out at 37-42 weeks gestation, deliveries in cases of vasa previa are usually carried out earlier, namely at 35-37 weeks gestation. 

This is done to prevent the baby’s head from descending towards the birth canal and pressing on its own blood vessels. In addition, it is also to prevent the water from breaking (which will cause the fetal blood vessels to rupture).

Delivery in cases of vasa previa must be carried out in a hospital that has adequate neonatal intensive care unit (NICU) facilities and a pediatrician who is capable of handling it. This is because after being born, the baby often needs blood transfusions and intensive care for some time.


Until now there is nothing that can be done to prevent vasa previa.

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