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Definition

The placenta is an organ that nourishes the baby in the womb. Placenta previa is when the placenta covers part or all of the cervix.

Placenta Previa
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Causes

The cause is not known. It is likely due to prior injury and scarring of the lining of the womb. This can happen if you have had many pregnancies, a cesarean section (C-section), or prior placenta previa.

Risk Factors

This health problem is more common in mothers who are older.

Factors that may raise your chance of this are:

  • Pregnancy with more than one fetus
  • Prior placenta previa
  • Prior C-section
  • Fertility treatments

Symptoms

Symptoms differ and depend on how much of the cervix is covered. The main sign is painless bleeding from the birth canal. It can range from light to very heavy. It most often happens during late pregnancy. It often happens after sex.

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done.

Your blood will be tested.

An ultrasound will be done.

Treatment

Treatment depends on many things, such as the amount of bleeding and how far along you are. You may need:

  • Pelvic rest—do not have sex or use tampons
  • To stay in the hospital if you are at high risk for problems
  • Medicines to put off labor and give the fetus a chance to grow

You will need to have your baby by C- section if the placenta covers the cervix, there is heavy bleeding during labor, or other health problems happen.

Prevention

This health problem can't be prevented.

RESOURCES

The American Congress of Obstetricians and Gynecologists  http://www.acog.org 

Family Doctor—American Academy of Family Physicians  http://familydoctor.org 

CANADIAN RESOURCES

Health Canada  https://www.canada.ca 

Women's Health Matters  http://www.womenshealthmatters.ca 

References

Placenta previa. American Pregnancy Association website. Available at: http://americanpregnancy.org/pregnancy-complications/placenta-previa. Updated May 3, 2017. Accessed August 8, 2018.

Placenta previa. EBSCO DynaMed Plus website. Available at:  https://www.dynamed.com/topics/dmp~AN~T116879/Placenta-previa  . Updated May 18, 2018. Accessed August 8, 2018.

Podrasky AE, Javitt MC, Glanc P, et al. American College of Radiology (ACR) Appropriateness Criteria for second and third trimester bleeding. Available at: http://www.acr.org/~/media/ACR/Documents/AppCriteria/Diagnostic/SecondAndThirdTrimesterBleeding.pdf. Updated 2013. Accessed June 6, 2016.

Pregnancy complications. Office on Women's Health website. Available at: http://www.womenshealth.gov/pregnancy/you-are-pregnant/pregnancy-complications.html. Updated June 6, 2018. Accessed August 8, 2018.

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