Vasa Previa

Vasa previa is a rare pregnancy complication that can lead to stillbirth when unmanaged.

Fortunately, the experienced OB/GYNs at Maiden Lane Medical in Midtown Manhattan, New York City, offers expert diagnosis, pregnancy management, and cesarean deliveries to protect you and your baby.

Call Maiden Lane Medical today or schedule a consultation online if you’re looking for expert obstetric care.

A young African American doctor doing a ultrasound on a pregnant patient. Maiden Lane Medical | New York, NY

What is vasa previa?

Vasa previa is a rare but dangerous condition that occurs when fetal umbilical cord blood vessels run too close or over the internal opening of the cervix. As a result, the blood vessels are not within the placenta membrane and are at risk of rupture during childbirth, leading to fetal hemorrhage. When undiagnosed and managed, vasa previa increases the risk of stillbirth.

What is placenta previa?

Placenta previa occurs when the placenta attaches to the uterine wall in a location that covers the uterine opening to the cervix. There are three types of placenta previa:

  • Complete placenta previa – the uterine opening is completely covered
  • Partial placenta previa – the uterine opening is partially covered
  • Marginal placenta previa – the placenta is close to but not covering the opening

The condition is relatively rare, occurring in only 4 out of every 1,000 pregnancies beyond the 20th week. In most cases, when the placenta implants near the uterine opening, it moves away from the opening as the pregnancy progresses.

What are the common vasa previa and placenta previa symptoms?

Vasa previa and placenta previa don’t usually cause noticeable symptoms. However, both can cause uterine bleeding during pregnancy. If you have any bleeding while you’re pregnant, contact your OB/GYN immediately or go to the emergency room for medical care. 

What causes vasa previa?

Vasa previa is caused by an umbilical cord abnormality known as velamentous cord insertion. This is the clinical term for when the umbilical cord goes into the membranes, resulting in unprotected blood vessels leading to the placenta. 

Vasa previa can also be caused by a bilobed placenta, which occurs when the placenta is in two pieces, and the blood vessels are exposed where they pass between the two parts. 

Some of the potential risk factors for vasa previa include:

  • Placenta previa
  • Previous cesarean deliveries
  • Multiple fetuses
  • Previous uterine surgery

Assisted reproductive treatments such as in vitro fertilization (IVF) may also increase your risk of vasa previa.

What causes placenta previa?

Placenta previa usually resolves on its own as pregnancy progresses.

However, when the condition persists past the 20th week of gestation, it could be due to:

  • Abnormal uterine shape
  • Uterine scarring
  • Enlarged placenta

You may have an enlarged placenta if your body doesn’t efficiently transfer oxygen and nutrients to your fetus. This could be due to multiple gestation, smoking, or living at a high altitude. 

How are vasa previa and placenta previa diagnosed?

Vasa previa and placenta previa are usually diagnosed during an ultrasound exam. When you have your 20-week ultrasound, your doctor looks for various signs to confirm the health and development of your baby. They also check for abnormalities, including vasa previa and placenta previa. 

In some cases, if your ultrasound shows signs of either of these conditions, your doctor may order additional imaging, including transvaginal Doppler screening. Doppler uses color imaging to show blood moving through your arteries and veins. These detailed images provide valuable information about the blood vessels in and around the placenta.

How are vasa previa and placenta previa treated?

There isn’t a treatment for either vasa previa or placenta previa. However, once the condition is diagnosed, your OB/GYN can monitor your pregnancy with additional ultrasounds and provide advice to lower your risk of membrane or blood vessel rupture. 

For example, you may need to avoid any strenuous activity for the remaining weeks of your pregnancy, and your doctor may suggest bed rest or even hospitalization for the third trimester in some cases. Your OB/GYN may also prescribe corticosteroids to boost lung development in your baby.

In many cases, your OB/GYN will recommend a cesarean delivery to reduce the risk of bleeding during labor and delivery. In addition, the surgical delivery option helps your doctor control the situation and reduce stress on your baby.

Medically Reviewed By

Jill-Ann Swenson, MD, FACOG
Board Certified OB/GYN

Expert Medical Services

Book an Appointment

Find a caring and knowledgeable doctor. Book your appointment today.