What is vasa praevia?

Vasa praevia is a rare but serious pregnancy complication.

It occurs when blood vessels connecting your baby to the placenta are unprotected by placental tissue or the umbilical cord. These unprotected blood vessels pass near or over your cervix (the opening between your uterus (womb) and your vagina).

Usually, the umbilical cord connects your baby to your placenta. Both blood and oxygen move through the blood vessels in the umbilical cord to keep your baby healthy.

The unprotected blood vessels in women with vasa praevia are very delicate. They can tear during labour or when your waters break. This can be dangerous because any blood loss comes from your baby.

In Australia, vasa praevia happens in just over 2 in every 10,000 pregnancies.

What are symptoms of vasa praevia?

The main symptom of vasa praevia is fresh vaginal bleeding — with or without your waters breaking.

Some women have no early symptoms of vasa praevia.

You may be diagnosed with vasa praevia during early labour, when you have a vaginal examination. Signs of vasa praevia during labour are:

• vaginal bleeding
• your midwife or doctor being able to feel the blood vessels when they do a vaginal exam
• your baby being in distress after your waters break — this may be noticed as a change in your baby’s heart rate

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes vasa praevia?

We don’t know exactly what causes vasa praevia. But we know the chances of having it are higher if:

• your placenta or umbilical cord grow in an unusual way
• you have placenta praevia (low-lying placenta)
• you’re having twins, triplets or more
• you’re having an IVF pregnancy

Having vasa praevia in a previous pregnancy doesn’t mean you are more likely to get it again.

When should I see my maternity care provider?

If you have any vaginal bleeding, you should call your doctor or midwife straight away. Some medical centres are open outside of normal business hours for urgent appointments.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

What is a vaginal ultrasound?

A vaginal ultrasound gives clearer images than a standard abdominal (tummy) ultrasound.

When you have a vaginal ultrasound, your healthcare professional will gently put the ultrasound probe into your vagina. The probe has a sterile (clean) cover. Images of your uterus are then shown on a screen.

You should be informed about an vaginal ultrasound scan beforehand. You should be asked to give your informed consent before the test is started. You may be asked to sign a written consent form.

A vaginal ultrasound may be uncomfortable, but it’s not painful.

GLOSSARY OF PREGNANCY AND LABOUR — Glossary of common terms and abbreviations used by health professionals in pregnancy and labour.

How is vasa praevia treated?

If you have vasa praevia, you may be admitted to hospital when you are about 30 weeks pregnant. You will stay in hospital until you have your baby. This means that if you go into labour early, you can have an emergency caesarean section quickly.

Your healthcare team will plan to deliver your baby by caesarean section before labour starts. This will often happen between 34 and 36 weeks of pregnancy. You may be offered steroids to help your baby’s lungs mature before the birth.

Your doctor or midwife can explain the safest pregnancy and birth options for your situation.

What are the potential complications of vasa praevia?

You may have complications of vasa praevia if the unprotected blood vessels bleed. This can happen when:

• you go into labour
• your waters break
• your cervix opens

Losing blood can seriously harm your baby. If this happens, your baby will need to be born by an emergency caesarean section.

Can vasa praevia be prevented?

There is nothing you can do to prevent vasa praevia. But your baby’s health outcomes and chances of survival are better if vasa praevia is diagnosed during your pregnancy, rather than during labour.

It's important to attend your antenatal appointments throughout your pregnancy. This helps your health team find any problems early and gives you and your baby the best chance of a safe birth.

Always tell your midwife or doctor about any symptoms that you are concerned about.

Resources and support

To learn more and get support, you can contact the organisations listed below.

• Australian Birth Trauma Association offers advice, resources, and a peer support service.
• Centre of Perinatal Excellence (COPE) has information and a list of support services.
• Perinatal Anxiety & Depression Australia (PANDA) offers support to those planning, starting or raising a family — call on 1300 726 306 to speak with a counsellor.