Placenta Previa: Meaning, Causes, Symptoms, Treatment

Written by Medicover Team and Medically Reviewed by Dr Shraddha S Sabnis , Gynecologists

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Placenta previa is a condition that can develop during pregnancy where the placenta lies unusually low in the uterus, partly or completely covering the cervix (the opening to the birth canal). Since the placenta plays a vital role in providing oxygen and nutrients to the baby, its position is very important. When it is too low, complications may arise during pregnancy and delivery.

Placenta previa is not very common, but when it happens, it requires careful monitoring and management to protect both the mother and the baby. Understanding the placenta previa type, its symptoms, causes, complications and treatment options helps expectant mothers feel more prepared and reduces anxiety around the condition.

Types of Placenta Previa

The position of the placenta can vary and based on this, doctors classify placenta previa into different categories. These are often called placenta previa types classifications.

• Type 1 (Low-Lying Placenta): The placenta is attached in the lower part of the uterus but does not reach the cervix.
• Type 2 (Marginal Placenta Previa): The placenta reaches the edge of the cervix but does not cover it.
• Type 3 (Partial Placenta Previa): The placenta partially covers the cervix, making vaginal delivery difficult.
• Type 4 (Complete Placenta Previa): The placenta fully covers the cervix, blocking the baby's passage and usually requiring cesarean delivery.

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Symptoms of Placenta Previa

Recognising placenta previa symptoms early is important because it can prevent serious complications. The most common symptom is painless vaginal bleeding during the second or third trimester.

Other placenta previa symptoms may include:

• Bright red vaginal bleeding usually occurs after 20 weeks of pregnancy.
• Repeated episodes of bleeding that may stop and start again.
• No pain or only mild discomfort during bleeding (different from other pregnancy problems that cause painful bleeding).
• In some cases, contractions or premature labour may accompany bleeding.

It's important to remember that not all women with placenta previa experience symptoms. Sometimes, it is detected during a routine ultrasound.

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Causes of Placenta Previa

The exact placenta previa causes are not always clear, but several factors can increase the risk of this condition.

• Previous pregnancies: Women who have had several pregnancies are more likely to develop placenta previa because repeated pregnancies can affect where the placenta attaches.
• Uterine scarring: Scars from past C-sections, surgeries or D&C can make it harder for the placenta to attach normally, increasing the risk of placenta previa.
• Multiple pregnancies: Carrying twins, triplets or more stretches the uterus, which can change where the placenta attaches and raise the chance of placenta previa.
• Maternal age:Women over 35 have a higher chance of placenta previa because age can affect the uterus and how the placenta implants.
• Lifestyle factors: Smoking or using drugs during pregnancy can affect blood flow and placental attachment, raising the risk of placenta previa.
• Unusual uterus shape: If the uterus has an unusual shape, the placenta may attach incorrectly, increasing the likelihood of placenta previa.

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Complications of Placenta Previa

Placenta previa can cause serious health risks if not treated. Understanding its signs, care, and placenta previa complications helps protect both mother and baby.

• Severe bleeding can be life-threatening for both mother and baby if not treated promptly.
• Preterm birth may be needed if bleeding cannot be controlled during pregnancy.
• The placenta may separate from the uterus too early, causing placental abruption.
• Heavy blood loss can lead to shock if not managed quickly and effectively.
• Reduced blood and nutrients from the placenta may cause problems in fetal growth.
• Most women with placenta previa require cesarean delivery to provide safety.

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When to See a Doctor

Seek medical help immediately if you notice:

• Bright red vaginal bleeding, especially in the second half of pregnancy.
• Bleeding without pain.
• Signs of preterm labor like contractions or back pain.
• Dizziness, weakness or fainting after heavy bleeding.

Never ignore any bleeding during pregnancy, as it can be dangerous for both the mother and the baby.

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Diagnosis of Placenta Previa

Accurate placenta previa diagnosis is essential for proper management. The condition is usually diagnosed through:

• Ultrasound scan: The most common and reliable method. A transabdominal or transvaginal ultrasound can show the placenta's position.
• MRI (Magnetic Resonance Imaging): Sometimes used if the ultrasound does not give a clear picture, especially when placenta accreta is suspected.
• Physical examination: Usually avoided when placenta previa is suspected, as touching the cervix can trigger heavy bleeding.

Doctors often monitor the placenta's position throughout pregnancy since, in some cases, the placenta may move up as the uterus grows, resolving the issue naturally.

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Placenta Previa Management and Treatment

The approach to placenta previa treatment depends on the severity of the condition, amount of bleeding, the type of placenta previa and how far along the pregnancy is.

Conservative Management

In mild cases of placenta previa, careful monitoring and simple lifestyle adjustments can help prevent bleeding, protect the baby, and reduce the risk of complications.

• Rest and limit activity
• Avoid sexual intercourse
• Regular prenatal checkups
• Gentle walking if approved

Medical Management

When bleeding is heavy or recurring, hospital care may be necessary to stabilise the mother and provide the baby's safety.

• Hospitalization for close monitoring
• Blood transfusions if needed
• Corticosteroids for baby's lung development

Delivery Planning

Proper planning for delivery is critical in placenta previa to prevent emergencies and ensure a safe birth for both mother and baby.

• Cesarean delivery if placenta covers cervix
• Emergency C-section for uncontrolled bleeding

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Precautions

Women diagnosed with placenta previa should follow certain precautions to reduce complications:

• Avoid heavy lifting and strenuous activities.
• Do not insert anything into the vagina, including tampons or douches.
• Avoid sexual intercourse if advised by your doctor.
• Stay close to a hospital if the risk of bleeding is high.
• Keep emergency contacts and hospital details ready.
• Attend all prenatal appointments for regular monitoring.

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Conclusion

Placenta previa is a high-risk pregnancy condition but can often be managed successfully with the right care. Recognizing placenta previa symptoms, understanding placenta previa causes and following the treatment plan are crucial for protecting the health of both mother and baby. With close monitoring, medical support and proper delivery planning, most women go on to have safe outcomes.

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