Placenta Previa

What is placenta previa?

• Placenta previa is a condition that can occur in your uterus (womb) before your baby is born. With placenta previa, your placenta grows near or over your cervix (opening out of your uterus). Your placenta is attached to the wall of your uterus. The placenta forms during pregnancy and brings oxygen and nutrition from the mother to the fetus (unborn baby). The placenta also removes waste products from the fetus. Normally, your placenta grows in the upper part of your uterus. When your placenta grows near your cervix, it may block the opening to your vagina. You may have vaginal bleeding that could harm you and your unborn baby. Placenta previa may also resolve on its own before your baby is ready to be born.
  
  
• When you have placenta previa, you are at risk of having placenta accreta. Placenta accreta is when your placenta attaches deep into the wall of your uterus. The deep attachment makes it hard for your placenta to come out after your baby is born. Having placenta accreta with placenta previa puts you at higher risk for bleeding. Ask your caregiver for more information about placenta accreta. Treatment and care may help decrease or resolve your bleeding. Treatment and care may also save yours and your baby's life.

What causes placenta previa and what increases my risk for placenta previa?

The exact cause of placenta previa is not clear. Your risk increases as you get older. Your risk also increases if you are of Asian descent. The following may also increase your risk:

• Infertility treatments: Having treatments to increase your chances of getting pregnant may make you more likely to have placenta previa.
  
  
• Medical conditions: High blood pressure and past uterine infections increase your risk for placenta previa.
  
  
• Pregnancy: The more times you have been pregnant, the higher your risk is for the condition. Your risk increases if your pregnancies are one year or less apart. Being pregnant with more than one baby such as twins, also increases your risk. Past pregnancies that resulted in an abortion or miscarriage may also increase your risk for placenta previa.
  
  
• Past C-section: A C-section is surgery to deliver your baby through a cut in your lower abdomen (stomach) and uterus. A past C-section may cause changes in your uterine tissue. The tissue changes may increase your risk for placenta previa.
  
  
• Smoking and street drug use: Smoking before and during pregnancy increases your risk for placenta previa. Use of street drugs such as cocaine also may lead to placenta previa.
  
  
• Uterine scarring: Placenta previa is more likely to occur if you have scarring in your uterus. Scarring may occur from a past surgery or pregnancy. Scarring may increase the chance your placenta will grow in the lower part of your uterus.

What are the signs and symptoms of placenta previa?

• Vaginal bleeding: Bleeding usually occurs in the late second or early third trimester of pregnancy, but can occur at any time. You may have small or large amounts of bleeding that normally does not cause pain. You may have bleeding after having sex. Bleeding may also occur suddenly and may be an emergency.
  
  
• Contractions: With contractions, you may have abdominal pain or cramping.

How is placenta previa diagnosed?

Placenta previa is often found by during a normal pregnancy visit with your caregiver. The later in your pregnancy it is found, the higher the chance is it will not go away. Your caregiver will ask you about your health and any previous pregnancies. Tell your caregiver if you have had past uterine surgeries or procedures. Your caregiver may check your cervix by gently putting a speculum into your vagina. A speculum is a tool that opens your vagina to help your caregiver see your cervix. You may also have any of the following:

• Ultrasound: An ultrasound uses sound waves to show pictures of your organs and tissue on a TV-like screen. You may have any of the following types of ultrasound done:
  
  
  • Transvaginal ultrasound: During a transvaginal ultrasound (TVS) a small tube is placed inside your vagina to look at your uterus. It may show if your placenta lies in the lower part of your uterus. A TVS may also show how close your placenta is to the edge or top of your cervix.
    
    
  • Abdominal ultrasound: During an abdominal ultrasound a small device will be moved around your abdomen to show pictures of your uterus. Your caregiver may want you to have a full bladder for this test. It may show if your placenta is blocking the opening of your uterus. It may also show problems with your baby, such as slow growth.
    
    
  • Doppler ultrasound: A Doppler ultrasound may be done to check if your placenta has grown into the wall of your uterus.
  
  
• Magnetic resonance imaging: During magnetic resonance imaging (MRI), pictures are taken of your pelvis. The MRI pictures may show where your placenta is in your uterus. An MRI may also show if and how deep your placenta has grown into your uterine wall. You will need to lie very still during an MRI. Never enter the MRI room with metal objects. This can cause serious injury.

How is placenta previa treated?

Placenta previa may resolve later in your pregnancy, and you may not need treatment. Your placenta may move when your uterus changes shape as you get closer to delivery. If you need treatment, it may depend on how far along you are with your pregnancy. Your treatment also depends on how much of your cervix is covered by your placenta. You may need any of the following:

• Bed rest: You may need to be on bed rest until your baby is ready to be born. You may be able to rest at home or you may need to stay in the hospital. If you are in the hospital, your caregiver may keep you on a monitor. A monitor is used to watch your vital signs (heart rate, breathing, and blood pressure). You may also need to wear a fetal monitor. Talk to your caregiver about what activities are OK while you are on bed rest.
  
  
• Blood transfusion: You may need a blood transfusion if you lose a large amount of blood. During a blood transfusion, you will get donated blood through an IV. An IV is a tube that is put into your vein for given medicines or fluids such as blood. You may need a transfusion while you are still pregnant or after your baby is born.
  
  
• Medicines:
  
  
  • Steroids: Steroids may be given if you need to deliver your baby earlier than expected. These medicines help your baby's lungs to mature and prevent breathing problems after he is born.
    
    
  • Rhesus immune globulin shot: A Rhesus immune globulin shot (RhIG) may be given before your baby is born. RhIG is needed if you and your baby have an Rh type mismatch. Rh mismatch means that your baby has a protein in his blood that you do not. Your body may make antibodies against your baby's blood and destroy his blood cells. RhIG shots are given to prevent this from happening. Ask you caregiver for more information about RhIG shots.
    
    
  • Tocolytics: Tocolytics are given to stop contractions if your baby is not ready to be born. Contractions are when the muscles of your uterus tighten and loosen.
  
  
• Amniocentesis: An amniocentesis test may be done between weeks 36 to 37 of your pregnancy, if you are not bleeding. This test is done to check your unborn baby's lungs if you have a C-section date planned. Ask your caregiver for more information about an amniocentesis.
  
  
• Delivery of your baby: Early delivery of your baby may be needed when you have placenta previa. If your due date is close, and your placenta does not cover your cervix, you may be able to give birth vaginally. If your placenta covers most or all of your cervix, a C-section will be done. A C-section may also be done if you have heavy bleeding or you or your baby is in danger.

What are the risks to my health with placenta previa?

Risks to your health may depend on how low your placenta is lying in your uterus. Do not ignore any signs and symptoms you have, as they could mean you are in danger. Having placenta previa may increase your risk for blood clotting. Your placenta may pull away from the wall of your uterus when you have contractions. You may have vaginal bleeding that cannot be stopped or controlled. Placenta previa can be a very serious condition, and you may die. Having placenta previa may make you feel worried and scared. Talk to your caregiver, family, and friends about your feelings. Ask your caregiver if you have questions or concerns about your condition, treatment, or care.

What are the risks to my unborn baby with placenta previa?

If you have placenta previa, your unborn baby may not grow as he should. Your unborn baby may have problems with his heart rate. Your unborn baby may be forced into an abnormal birthing position in your uterus. Your baby may be born too early, and his lungs may not function properly. If your baby is born too early, he may have serious medical problems, and he may die. Talk to your caregiver about any concerns you have about your unborn baby's health.

What can I do to help myself if I have placenta previa?

• Do have a safety plan and someone to take you to the hospital if needed.
  
  
• Do stay within a short distance to the hospital so you can get there quickly.
  
  
• Do not have sex in your third trimester.

When should I call my caregiver?

Call your caregiver if:

• You have abdominal cramps, pressure, or tightening.
  
  
• Your heart is beating faster than what is normal for you.
  
  
• You have any questions or concerns about your pregnancy, condition, or care.

When should I seek immediate help?

Seek care immediately or call 911 if:

• You have any amount of bleeding from your vagina.
  
  
• You are having severe abdominal pain or contractions.
  
  
• You have new and sudden chest pain or trouble breathing.
  
  
• You fainted or feel too weak to stand up.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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