Placenta Accreta

Overview

What is placenta accreta?

Placenta accreta is a condition where the placenta (the food and oxygen source for a fetus) grows too deeply into the wall of your uterus. In a typical pregnancy, the placenta easily detaches from the wall of your uterus after your baby is born. In placenta accreta, the placenta has grown into your uterine wall and doesn’t separate easily following delivery. In severe cases, it can lead to life-threatening vaginal bleeding. It may require a blood transfusion and hysterectomy (removal of your uterus). Pregnancy care providers diagnose placenta accreta during pregnancy or during delivery. Treatment usually involves an early Cesarean delivery (C-section) followed by a hysterectomy to minimize the risk of severe complications.

What are the different types of placenta accreta?

There are three types of placenta accreta. Providers determine the type based on how deeply the placenta is attached to your uterus.

  • Placenta accreta: The placenta firmly attaches to the wall of your uterus. It doesn’t pass through the wall of the uterus or impact the muscles of the uterus. This is the most common type.
  • Placenta increta: In this type, the placenta is more deeply embedded in the wall of your uterus. It still doesn’t pass through the uterine wall but is firmly attached to the muscle of the uterus. Placenta increta accounts for about 15% of cases.
  • Placenta percreta: The most severe of the types, placenta percreta happens when the placenta passes through the wall of your uterus. The placenta might grow through your uterus and impact other organs, such as your bladder or intestines. It accounts for about 5% of cases.

Who’s at risk for placenta accreta?

You’re at higher risk for placenta accreta if you:

  • Have had previous Cesarean deliveries.
  • Have a placenta in an abnormal location in your uterus.
  • Have had previous surgeries on your uterus.
  • Have had more than one pregnancy.
  • Are pregnant via IVF.

Does placenta accreta harm the baby?

Placenta accreta doesn’t directly harm your unborn baby. Placenta accreta often leads to preterm birth. Preterm birth carries risks such as respiratory problems or trouble gaining weight. Babies born before 37 weeks of pregnancy have a higher risk of being admitted to a neonatal intensive care unit (NICU) for specialized treatment.

What are the risks of placenta accreta to the birthing person?

  • Premature delivery.
  • Damage to your uterus and surrounding organs.
  • Loss of fertility due to hysterectomy.
  • Excessive bleeding that requires a blood transfusion.
  • Blood clotting issues.
  • Lung or kidney failure.
  • Death.

How common is placenta accreta?

Placenta accreta may affect up to 1 in 533 pregnancies. The occurrence of placenta accreta has increased over the last several decades, mostly due to the increased rate of C-sections.

Symptoms and Causes

What causes placenta accreta?

Abnormalities with the lining of your uterus cause placenta accreta. Your uterine lining can become damaged or scarred from prior uterine surgeries. It can also happen to people who haven’t had any uterine surgery.

The risk factors for placenta accreta are:

  • Multiple C-sections: People who’ve had multiple C-sections have a higher risk of developing placenta accreta. This results from scarring of your uterus from the procedures. The more cesarean sections a woman has over time, the higher her risk of placenta accreta. Multiple cesareans are present in over 60% of cases.
  • History of uterine surgeries: If you’ve had a uterine fibroid (a noncancerous growth or tumor of the uterine muscle) removed, the scarring could lead to placenta accreta. Surgeries such as curettage (removing tissue from your uterus) or endometrial ablation can also lead to scarring.
  • Placenta previa: This condition occurs when the placenta blocks your cervix. In people with placenta previa and a history of prior C-section deliveries, the risk for placenta accreta increases with the number of C-sections they’ve had.

What are the symptoms of placenta accreta?

There are usually no symptoms of placenta accreta. In some cases, you may experience bleeding in the third trimester of pregnancy (weeks 28 to 40) or pelvic pain (from the placenta pressing on your bladder or other organs).

Diagnosis and Tests

How is placenta accreta diagnosed?

A prenatal ultrasound can diagnose placenta accreta during pregnancy. Magnetic resonance imaging (MRI) can be helpful in some cases to show how deeply the placenta has penetrated your uterine wall.

In other cases, pregnancy care providers discover placenta accreta after your baby is born. Ideally, uterine contractions expel the placenta within 30 minutes of delivery. When this doesn’t occur, your provider may suspect placenta accreta.

How important is an early diagnosis of placenta accreta?

An early diagnosis of placenta accreta is essential because it can allow multiple healthcare providers to become involved in your pregnancy and delivery care. For example, a neonatologist may be involved in your newborn’s care, or a perinatologist may be involved in yours. Your provider will monitor you closely to ensure the best results for you and your baby.

Having the right people involved could prevent the removal of your uterus (hysterectomy) or life-threatening blood loss. In some cases, providers can’t avoid a hysterectomy and blood transfusion despite an early diagnosis; however, risks for other complications decrease with early diagnosis.

Management and Treatment

How is placenta accreta treated?

Treatment of placenta accreta can vary. If your provider diagnoses it before delivery, they’ll monitor you closely for the rest of your pregnancy. You may be hospitalized or put on bed rest to prevent preterm labor. Your provider will schedule a C-section to deliver your baby, usually around between 34 and 37 weeks. This is done to decrease the risk of bleeding from contractions or labor. If you wish to have future pregnancies, your healthcare provider can try to save your uterus.

However, in severe cases where the placenta is deeply or firmly attached or invading into other organs, a hysterectomy (removal of the uterus) may be the safest option. A Cesarean hysterectomy is when your uterus is removed at the time of a C-section delivery. In this case, your provider will deliver your baby, your uterus and the placenta at the same time. Removing your uterus with the placenta still attached minimizes the risk of excessive bleeding (hemorrhaging).

Some healthcare providers will leave small parts of the placenta inside your uterus because the placenta dissolves over time. This also carries risks like severe vaginal bleeding, infection and blood clots. It may still be difficult to get pregnant in the future.

How early do you deliver with placenta accreta?

Most healthcare providers will recommend a C-section between 34 and 37 weeks gestation if there are no complications. This prevents you from having contractions or going into labor, as these can cause significant bleeding. Your healthcare provider may give you corticosteroids to help develop your baby’s lungs.

Prevention

Can I prevent placenta accreta?

You can’t prevent placenta accreta. The risk of placenta accreta increases if you’ve had multiple C-sections or a placental disorder like placenta previa. Talk to your provider about your chances of developing placenta accreta based on your health history.

Outlook / Prognosis

What is the outlook for people with placenta accreta?

The outlook is generally good when pregnancy care providers diagnose placenta accreta during pregnancy. However, there will be complications associated with preterm labor and a possible hysterectomy. If your obstetrician removes your uterus, you’ll lose the ability to become pregnant again. This condition can also lead to massive blood loss, injury to the bowel or bladder and even death.

Can I have another baby after placenta accreta?

It depends on if you had a hysterectomy. Talk to your healthcare provider if you wish to become pregnant in the future. They may be able to prevent a hysterectomy to preserve your fertility.

What is the survival rate of placenta accreta?

The survival rate of placenta accreta is generally good. In most cases, this means you’ll have a hysterectomy to prevent postpartum hemorrhaging or other severe complications.

Living With

When should I call my healthcare provider?

Placenta accreta is a high-risk pregnancy condition. Your healthcare provider will monitor you closely and let you know what to expect for the rest of your pregnancy, delivery and recovery. Contact them if you have questions about your diagnosis — they’re there to help you.

If at any point you begin bleeding heavily (soaking through a pad in less than an hour) or have pelvic pain, call 911.

What questions should I ask my obstetrician?

If you have placenta accreta, it’s normal to have questions. Some common questions to ask are:

  • Will I have to give birth early?
  • Is my baby safe?
  • How is this condition treated?
  • Do I need to be on bedrest or modify my daily activities?
  • How do I know when to go to the hospital?
  • Is a vaginal delivery possible?
  • Will I be able to have a baby in the future?
  • Will I need a hysterectomy?

Frequently Asked Questions

Does placenta accreta cause a hysterectomy?

Your healthcare provider makes every attempt to save your uterus; however, the risks of doing so may be too high. Most people with severe placenta accreta lose their uterus due to the life-threatening bleeding that can occur. Talk to your healthcare provider about the likelihood of needing a hysterectomy based on your condition.

A note from Cleveland Clinic

Placenta accreta is a potentially life-threatening condition that doesn’t typically cause symptoms during pregnancy. However, an early diagnosis via ultrasound and close monitoring can help lower your risk for complications from placenta accreta. In some cases, placenta accreta isn’t discovered until after your baby is delivered. Talk to your healthcare provider about what you can expect if you have placenta accreta. They’re there to keep you and your baby safe and healthy.

Last reviewed by a Cleveland Clinic medical professional on 09/26/2022.

References

  • ACOG. Obstetric Care Consensus. No. 7. Placenta Accreta Spectrum. (https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2018/12/placenta-accreta-spectrum) Accessed 9/26/2022.
  • American Pregnancy Association. Placenta Accreta. (https://americanpregnancy.org/healthy-pregnancy/pregnancy-complications/placenta-accreta/) Accessed 9/26/2022.
  • March of Dimes. Placental accreta, increta and percreta. (https://www.marchofdimes.org/complications/placental-accreta-increta-and-percreta.aspx) Accessed 9/26/2022.
  • National Accreta Foundation. What do Accreta Patients Need to Know? (https://www.preventaccreta.org/faq) Accessed 9/26/2022.
  • Shepherd AM, Mahdy H. Placenta Accreta. (https://www.ncbi.nlm.nih.gov/books/NBK563288/) [Updated 2021 Oct 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Accessed 9/26/2022.

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