But don’t worry, because this condition can be avoided with proper and timely treatment.
What is Vasa Previa?
Vasa previa occurs when blood vessels from the baby’s umbilical cord or placenta run across or near the opening of your cervix (called the cervical os). These delicate vessels are not shielded by the umbilical cord or placental tissue, making them prone to rupture when your water breaks or labour begins. If these vessels burst, it can cause rapid and severe blood loss for your baby. The positive news is that with early diagnosis and proper management, the survival rate for babies is very high, around 98.6 per cent.There are two main types of vasa previa:
- Type I (velamentous cord insertion): The umbilical cord inserts into the membranes instead of the placenta, leaving the blood vessels unprotected as they travel to the placenta. If these vessels are near the cervix, they’re at risk of rupturing during labour.
- Type II (bilobed or multilobed placenta): When the placenta splits into two or more lobes and the blood vessels connecting them are located near the cervix, they can rupture and cause bleeding when labour begins.
Incidence of Vasa Previa
According to a 2015 case study published in The Journal of Obstetrics and Gynecology of India, the incidence of vasa previa varies from 1 in 1,275 to 1 in 8,333 pregnancies.Causes and Risk Factors
The exact cause of vasa previa is unknown, but certain factors can increase your chances of developing it. These factors are related to how the placenta or umbilical cord develops during pregnancy.Risk Factors for Vasa Previa
Some of the key factors that may make vasa previa more likely include:- Low-lying placenta or placenta previa: If your placenta is positioned low in the uterus or covers the cervix partially or fully.
- Multiple pregnancies: Carrying twins, triplets, or more can complicate placental development, increasing the chances of vasa previa.
- In vitro fertilisation (IVF): Pregnancies achieved through IVF have a higher chance of vasa previa.
- Velamentous cord insertion: When the umbilical cord inserts into the membranes rather than the placenta, it leaves blood vessels exposed.
- Bilobed or multilobed placenta: A placenta that splits into multiple lobes can result in unprotected vessels near the cervix.
- Previous uterine surgeries or C-sections: Scarring from prior surgeries may affect placental development.
- Multiple pregnancies in the past: Individuals who have had several pregnancies may have a slightly higher risk.
- Maternal age over 35: Older individuals may face an increased risk of placental complications.
Symptoms of Vasa Previa
Most of the time, vasa previa doesn’t cause noticeable symptoms during pregnancy, which is why routine prenatal screenings are so critical. In most cases, you won’t feel anything unusual until labour begins, and by then, it could be an emergency.However, there are a few signs to watch for:
- Painless vaginal bleeding: If the unprotected blood vessels rupture, you may notice sudden vaginal bleeding, often in the second or third trimester. If you notice the blood is a darker red, it could indicate it’s foetal blood and not yours. Contact your doctor immediately in such a situation.
- Foetal heart rate changes: Abnormalities in your baby’s heart rate detected during routine monitoring may signal distress caused by vasa previa.
- Preterm labour: Vasa previa may trigger premature contractions.
Diagnosing Vasa Previa
Modern technology makes it possible to detect vasa previa before it becomes a problem. It's important to get diagnosed early to prevent any serious complications.Vasa previa is commonly found during routine prenatal ultrasounds, between weeks 18 and 26. Your healthcare professional will carry out some tests to confirm the condition.
- Transvaginal ultrasound: This is the main tool for detecting vasa previa. It allows your doctor to see the position of the foetal blood vessels in relation to your cervix.
- Colour Doppler ultrasound: This advanced ultrasound technique shows blood flow in the vessels. It helps to identify if they’re near the cervical os.
- MRI (rare cases): If ultrasound results aren’t clear, an MRI might be used to get a more detailed view of the placenta and blood vessels.
- The position of your placenta in relation to the cervix opening.
- If the placenta has multiple lobes.
- The location of the umbilical cord and the path of the blood vessels.
Differential Diagnosis
Your doctor will also consider other conditions that might cause similar symptoms, such as:- Placenta previa: When the placenta covers the cervix, it can also cause bleeding.
- Placental abruption: The placenta detaches from the uterine wall prematurely.
- Uterine rupture: A rare but serious tear in the uterus.
Treatment and Management
There is no curative treatment, but it can be effectively managed with early diagnosis. The goal is to avoid vaginal delivery, which could cause the blood vessels to rupture, and instead plan for a controlled delivery.This condition can be managed through the following:
- Planned caesarean section: A C-section is almost always recommended and is scheduled between weeks 34 and 37. Admission to a unit with appropriate neonatal facilities is also advised to support the baby's care after birth.
- Non-stress tests: Your doctor may schedule regular non-stress tests about twice a week to monitor your baby’s heart rate.
- Corticosteroids: If there’s a chance of early delivery, you might receive steroid injections to help your baby’s lungs mature.
- Hospital monitoring: If you’re at risk of preterm labour, your doctor may recommend staying in the hospital for closer observation in the weeks leading up to your C-section.
Potential Complications
Vasa previa can lead to serious complications for you and your baby if it isn't diagnosed or managed properly. Take a look at why early detection is so important.Risks to Your Baby
- Foetal haemorrhage: If the blood vessels rupture, your baby could lose a significant amount of blood quickly. This can lead to distress or even stillbirth. The foetal death rate for undiagnosed vasa previa is 56 per cent.
- Preterm birth: Early delivery may be necessary, which can result in health issues related to prematurity.
- Neurodevelopmental challenges: Babies who experience distress during delivery may face long-term developmental challenges.
Risks to You
- Severe bleeding: A vessel rupture can cause heavy bleeding, leading to shock or the need for blood transfusions.
- Psychological impact: Dealing with a high-risk pregnancy can lead to anxiety or stress that might continue even after the baby is born.
Preventing Vasa Previa
There’s no guaranteed way to prevent vasa previa, as it’s largely related to how the placenta and umbilical cord develop. However, you can take steps to reduce the risk of complications:- Regular prenatal care: Attend all your prenatal appointments to catch any issues early.
- Routine ultrasounds: These screenings can detect vasa previa before it becomes a problem.
- Healthy lifestyle: Eating a balanced diet rich in folic acid and iron, staying hydrated, and avoiding smoking can support a healthy pregnancy.
- Vaccinations and hygiene: Staying up-to-date on vaccinations and practicing good hygiene can prevent infections that might complicate your pregnancy.
When to Seek Immediate Help
You should contact your healthcare professional right away if you experience:- Heavy vaginal bleeding, especially if it’s painless or dark red.
- Severe abdominal pain that doesn’t subside.
- A sudden decrease in your baby’s movements.
- Signs of preterm labour like regular contractions before 37 weeks.
FAQs on What is Vasa Previa? Know Its Symptoms, Risk Factors and Treatment Options
- What are the symptoms of vasa previa?
Most pregnancies with vasa previa have no symptoms until labour. Sudden painless vaginal bleeding and changes in the baby’s heart rate may occur if vessels rupture. - How is vasa previa diagnosed?
It is usually diagnosed through routine prenatal ultrasounds using transvaginal and colour Doppler techniques between weeks 18 and 26.
