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Vasa Previa


The Manual's Editorial Staff

Reviewed/Revised May 2023
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Topic Resources

What are the placenta and umbilical cord?

  • The placenta is an organ that grows on the inside, upper part of your uterus (womb) when you're pregnant

  • It has many large blood vessels to carry oxygen and nutrients from you to your baby

  • The placenta's blood vessels form the umbilical cord to connect the placenta to your baby

  • About 15 minutes after you deliver your baby, the placenta comes off your uterus and goes out your vagina

  • That's why it is also called the "afterbirth"

What is vasa previa?

Vasa previa is a problem with the blood vessels in the placenta. In vasa previa:

  • Some of the blood vessels don't go directly from the placenta to the umbilical cord the way they should

  • Instead, they're in the wrong place and go through the membranes (amniotic sac) that surround your baby

  • Your amniotic sac breaks open (ruptures) and amniotic fluid leaks out when labor starts—this is called having your "water break"

  • When your water breaks, the blood vessels that are in the wrong place can tear

  • This may cause your baby to lose a lot of blood or even die

What Is Vasa Previa?

In vasa previa, membranes that contain blood vessels from the fetus to the placenta cross the entrance to the birth canal (the opening of the cervix). When the membranes rupture (near the start of labor), these blood vessels can be torn.

What Is Vasa Previa?

What are the symptoms of vasa previa?

  • You may have painless vaginal bleeding when your water breaks, usually soon after you go into labor

  • Your baby’s heart rate may be slow

How can doctors tell if I have vasa previa?

Doctors may suspect vasa previa if an earlier routine ultrasound Ultrasonography Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called... read more Ultrasonography shows problems with the placenta. An ultrasound uses sound waves to create moving pictures of the insides of your uterus. A follow-up ultrasound, usually done with a device inserted into your vagina, can confirm that you have vasa previa.

How do doctors treat vasa previa?

If vasa previa is diagnosed before labor:

  • Doctors will see you twice a week to check on your baby

  • You may be hospitalized when you're 30 to 32 weeks pregnant, so that doctors can check on your baby all the time

  • You may be given a medicine called a corticosteroid to help your baby’s lungs grow

  • If you're between 32 and 35 weeks pregnant and your baby's lungs are developed enough, your doctors may suggest scheduling surgery to deliver your baby

  • You have a lot of vaginal bleeding

  • Your water broke

  • Your baby’s life is in danger

  • Vasa previa was not diagnosed before you went into labor

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