Everything You Need to Know About Placenta Previa

The placenta is a superstar organ designed to nourish your baby throughout your pregnancy. It’s nothing short of amazing! But what happens when your placenta decides to go its own way, and nestle in where it’s not meant to?

Placenta previa is a condition where the placenta covers part or all of the cervix. While it may sound scary, if diagnosed early, placenta previa often resolves on its own. And arming yourself with info about this pregnancy complication can offer some valuable peace of mind. Here is everything you need to know about placenta previa.

What is placenta previa?

Placenta previa is when the placenta sits low in the uterus, either partially or completely covering the cervix, and it affects about 1 in 200 pregnancies. (Normally, the placenta attaches itself to the tippity top—or the side—of the uterus.) Placenta previa not only blocks your baby’s exit, it puts expecting parents at risk for severe bleeding, especially when your cervix thins (effaces) and opens up (dilates).

Types of Placenta Previa

• Marginal placenta previa: The placenta is next to the cervix, but it’s not covering the opening. This type of placenta previa is more likely to resolve on its own before delivery.
  
• Partial placenta previa: Here, part of the cervical opening is covered by the placenta.
  
• Complete placenta previa: The placenta covers the entirety of the cervical opening, blocking the vagina. This type of placenta previa is the least likely version to correct itself.
  

Is a low-lying placenta the same as placenta previa?

When the placenta attaches low in the uterus, it’s often referred to as a low-lying placenta. The terms “marginal placenta previa” and “low-lying placenta” are often used interchangeably. However, it’s important to understand that these conditions usually are not permanent. As your uterus grows, a low-lying placenta often shifts away from the cervix. In fact, nearly 90% of low-lying placenta cases ultimately resolve by the third trimester, which is why it’s not considered a high-risk condition. This natural migration is one of the reasons early diagnosis and monitoring are so important in managing placenta previa.

What is the difference between placenta previa and placental abruption?

With placenta previa, the placenta remains firmly attached to the uterine wall despite its unusual position. Placental abruption, on the other hand, is a rare and potentially dangerous complication where the placenta partially or fully detaches from the uterus prior to delivery. While placental abruption can happen regardless of the placenta’s position, placenta previa does increase the risk of placental abruption.

What are symptoms of placenta previa?

Usually, there are no early tell-tale symptoms of placenta previa. The condition often turns up during a routine ultrasound. Among those who do report symptoms, the most common sign of placenta previa is painless vaginal bleeding that begins after 20 weeks of pregnancy—this symptom affects about one-third of parents-to-be with placenta previa.

Who is at risk for placenta previa?

Experts don’t know what exactly causes placenta previa, but they do know what can increase your chance of this condition. Placenta previa risk factors include:

• 
  Being 35 years old or older
  
• Carrying multiples
  
• Abnormally shaped uterus
  
• Prior placenta previa
  
• Prior c-section
  
• Numerous past pregnancies
  
• In vitro fertilization for infertility
  
• Past surgery on internal reproductive organs, such as dilation and curettage (D&C)
  
• Endometrial damage and uterine scarring
  
• Smoker
  
• Cocaine use
  

What are possible complications of placenta previa?

Because placenta previa is a major risk factor for postpartum bleeding (hemorrhage), your pregnancy will most likely be categorized as “high risk” if you have placenta previa. Potential complications from placenta previa include:

• 
  Anemia
  
• Blood transfusion
  
• Cesarean hysterectomy
  
• Emergency c-section
  
• Intensive care admission
  
• Injury to nearby organs
  
• Low birth weight
  
• Low blood pressure
  
• Newborn respiratory issues
  
• Placenta accreta spectrum (PAS)
  
• Placental abruption
  
• Postpartum hemorrhage
  
• Premature birth
  
• Severe bleeding during pregnancy, labor, or delivery
  
• Shortness of breath
  

What is placenta accreta spectrum (PAS)?

When the placenta grows outside of the uterus and invades surrounding organs it’s called placenta accreta spectrum (PAS). Roughly 3% of moms-to-be with placenta previa (and no prior c-sections) wind up with placenta accreta spectrum, according to the American College of Obstetricians and Gynecologists. One’s risk of PAS inches up with each cesarean birth, going from 11% with the second c-section and 40% for the third.

What is the best treatment for placenta previa?

The “best” placenta previa treatment depends on three key factors: How far along you are, the severity of bleeding, and the overall health of you and your baby-to-be. The ultimate treatment goal? To keep you pregnant as long as possible.

If you’re diagnosed with placenta previa early in pregnancy—and have no symptoms—there’s likely no need for treatment. Instead, you’ll undergo follow-up ultrasounds to track placenta placement and how much your cervical opening is covered. Experts recommend a follow up ultrasound at 28 to 32 weeks of pregnancy to detect persistent placenta previa.

In other cases, your provider may advise skipping from certain activities that could spur contractions and bleeding, such as:

• 
  No vaginal exams
  
• No penetrative vaginal sex
  
• No sex that leads to orgasm
  
• No moderate or strenuous exercise
  
• No lifting more than 20 pounds
  
• No standing for more than four hours
  

Providers may also recommend:

• 
  Bedrest
  
• Hospital monitoring
  
• Blood transfusions
  
• Corticosteroids, which are meds that speed Baby’s lung and organ development in case of a preterm delivery
  
• Elective c-section at 36 to 37 weeks
  

Can I have a vaginal delivery with placenta previa?

Maybe. If you’ve been diagnosed with marginal placenta previa, aka a low-lying placenta, you may get the go-ahead for a vaginal delivery, though you remain at an elevated risk of bleeding.

The truth is, a c-section is usually the safest delivery option, even if the placenta barely touches  your cervix. So, don’t be surprised if your provider schedules a c-section in advance. And if bleeding becomes severe at any point during pregnancy, an immediate c-section will likely be in the cards.

When should you call the doctor about placenta previa?

If you have vaginal bleeding during your second or third trimester, intense abdominal pain or cramps, contractions, or signs of preterm labor, call your healthcare provider right away. And seek emergency medical care for severe bleeding.

Placenta Previa: Final Thoughts

Though you may be able to reduce your risk for placenta previa by not smoking, refraining from using cocaine, and by only having a c-section if medically necessary, experts don’t yet know how to prevent placenta previa. Fortunately, for most parents-to-be receiving regular prenatal care, placenta previa will be detected before any worrisome symptoms appear. And catching placenta previa early allows your care provider plenty of time to minimize risks and—if necessary—develop a tailored treatment plan.

Healthy Pregnancy Need-to-Knows:

• Spot the Signs of Preeclampsia
  
• Why Meditation During Pregnancy Matters
  
• Get Some Sleep! An Exhaustive Guide to Pregnancy Exhaustion
  
• Pregnancy and Shortness of Breath: When to Worry
  

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REFERENCES

• March of Dimes: Placenta Previa
• Cleveland Clinic: Placenta Previa
• Placenta Previa, StatPearls, NCBI, December 2018
• Kaiser Permanente: Low-Lying Placenta Versus Placenta Previa
• MedlinePlus: Placenta Previa
• American College of Obstetricians and Gynecologists: Placenta Accreta Spectrum
• Lancaster General Health: How Can Placenta Previa Impact My Pregnancy?

Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.