Placenta Accreta

Placenta accreta occurs when the placenta—the organ that provides nutrients and other support to a developing fetus—attaches too deeply to the uterine wall. This often leads to two major complications: the placenta cannot normally deliver after the baby’s birth, and attempts to remove the placenta can lead to heavy bleeding. This is a serious condition that can cause complications for the baby and mother, especially during the delivery. With supervision by experienced clinicians, however, these complications and risks can be managed effectively.

Placenta Increta and Percreta

Placenta increta and placenta percreta are similar to placenta accreta, but more severe.

  • Placenta increta is a condition where the placenta attaches more firmly to the uterus and becomes embedded in the organ's muscle wall.
  • Placenta percreta is a condition where placenta attaches itself and grows through the uterus and potentially to the nearby organs (such as the bladder).

Obstetricians seek to make a specific diagnosis of accreta, increta or percreta before delivery using ultrasound and MRI imaging, but this is not always possible.

Mild Accerta

Moderate Accerta

Severe Accerta

Who is at Risk for Placenta Accreta?

Placenta accreta, often referred to as simply “accreta,” occurs in about 0.2 percent of all pregnancies. Women who have experienced one or more of the following factors are at a higher risk for this condition:

  • Previous Cesarean section
  • Abnormal position of the placenta within the uterus, including placenta previa (a condition where the placenta sits low in the uterus, usually over the cervix)
  • Maternal age greater than 35
  • Previous surgery on the uterus, such as fibroid removal or treatment of uterine scar tissue
  • In vitro fertilization
  • Some accreta patients have none of these known risk factors – we are in the process of learning more about this challenging condition.

Symptoms and Complications of Placenta Accreta

Placenta accreta generally has no symptoms. However, placenta previa, which often develops along with accreta, often presents with vaginal bleeding. Extreme cases of placenta accreta, in which the placenta begins to invade the bladder or nearby structures (known as placenta percreta) can present with bladder or pelvic pain, or occasionally with blood in the urine.

During a normal delivery, the placenta detaches from the uterus during the last stage of labor. This can also be referred to as the “afterbirth.” With accreta, the placenta is tightly attached to the uterine wall and does not separate naturally during delivery. This causes several complications for the baby and mother.

Complications and risks for the baby

  • When placenta accreta occurs with placenta previa, or when there is suspicion for percreta, the delivery is often scheduled prematurely. This will usually occur between 34 and 37 weeks gestation (3-6 weeks early), depending on the severity of the accreta.
  • Babies born at these gestational ages often require admission to a newborn intensive care unit, but their overall prognosis is good.
  • If there is early, heavy bleeding, then the delivery may need to occur even earlier. If heavy bleeding from a previa makes the mother unstable, then the baby can become unstable as well. The accreta itself is not directly harmful to the baby.

Complications and risks for the mother

  • Hemorrhaging (severe bleeding) may occur from an associated placenta previa, or from attempts to remove the placenta when it is stuck to the uterus. If not managed and treated carefully, this may be life threatening.
  • A vaginal birth is not always possible. Women who do deliver vaginally may require specialized procedures to remove the placenta and control hemorrhaging. If a placenta accreta is diagnosed before labor, the provider may recommend a Cesarean section.
  • A hysterectomy (the surgical removal of the uterus) may be required after delivery to remove the placenta and end blood loss.

Placenta Accreta Topics

Preventing Placenta Accreta

Currently we do not know how to prevent a placenta accreta when someone is trying to become pregnant. Researchers at BWH, however, are actively studying IVF strategies that may prevent some accretas. Because accreta is strongly associated with having a prior cesarean section or surgery on the uterus, avoiding these surgeries, when possible, may help to prevent some accretas. Nevertheless, even though some women with accretas have never had surgery and are not using IVF, we don’t know how these women develop accretas or how to prevent them.

What to Do if You Suspect You Have Placenta Accreta
  • If you experience heavy vaginal bleeding, seek emergency care immediately.
  • If you have any of the above risk factors for accreta, you should discuss the possibility of placenta accreta with your doctor.
  • Consider consulting with an obstetrician who has experience diagnosing and treating placenta accreta.
  • Educate yourself as to how accreta is diagnosed and treated, and learn to distinguish the facts from the myths about placenta accreta.
Diagnosis of Placenta Accreta

Detecting and treating placenta accreta is complex. The following information will help you understand how accreta is diagnosed, how you can work with your obstetrician in managing delivery risks, and how you can recover healthfully.

While the specifics of treating and recovering from accreta are different for each and every patient, there’s one commonality: all accreta patients should seek high-quality, individualized care from experienced specialists.

Placenta accreta is usually diagnosed with an ultrasound.

  • If the diagnosis is difficult using an ultrasound image, magnetic resonance imaging (MRI) may be helpful.
  • Researchers are looking for diagnostic blood tests to improve detection of this condition, but none are currently available.

Diagnosis before delivery is not perfect. In some cases, a placenta accreta cannot be detected before delivery. On the other hand, some women diagnosed with accreta go on to have an uncomplicated delivery. Patients can be best prepared by discussing their risks for accreta with their obstetrician and being sure that radiologists know to look for signs of accreta during ultrasound screening. If you are at higher risk for accreta, consider consulting with a center such as Brigham and Women's Hospital that specializes in this condition.

Being Pregnant with Placenta Accreta
  • Accreta patients can expect more ultrasounds or sometimes MRI, and extra consultations with specialists.
  • Conditions that often go along with accreta, such as previa, may require special treatment. This may include hospitalization if there is bleeding or premature labor.
  • Bed rest has not been shown to help placenta previa or placenta accreta. A careful discussion of risks and benefits should be discussed prior to stopping normal activities.
  • Patients with accreta may be discouraged from long distance travel, especially towards the end of the pregnancy.
Treatment for Placenta Accreta
  • Surgery is the most common and effective treatment for accreta. After the birth of the baby, this usually involves either the surgical removal of the placenta, or a hysterectomy to remove the uterus along with the accreta. The ovaries are almost always left in place if a hysterectomy is performed. This will prevent the mother from going into menopause.
  • In some cases, the majority of the placenta is removed surgically but a portion is left attached to the uterus to avoid a hysterectomy. This involves some medical risks and requires close follow-up with an experienced provider.
  • Learn more about our Surgical Obstetrics Program

Read about common placenta accreta myths.

The Right Medical Setting for Women with Placenta Accreta

It’s important to consult with a specialist who has experience with placenta accreta to help manage and care for your pregnancy. If possible, the delivery should occur at a specialized center where the staff is well trained and has experience with accreta deliveries, and where you will have access to a multidisciplinary team of specialists as needed.

Planning Your Delivery
  • Seek out information about placenta accreta so that you feel knowledgeable about the condition.
  • Discuss your options for delivery with your obstetrician and develop a detailed birth plan. A scheduled delivery is preferred, but be sure to also create a plan for an emergency delivery.
  • It may be necessary to be admitted to the hospital prior to delivery, especially if there is bleeding or if you live far from the hospital.
After Your Delivery

Carrying a high-risk pregnancy, undergoing a complicated delivery and experiencing a hemorrhage are extremely stressful situations. After delivery, women with accreta may experience some of the following:

  • A longer recovery time for the body to adequately heal.
  • Difficulty breastfeeding: This is usually possible after a delivery with accreta, even with a premature baby. Women should ask about lactation support when planning the delivery and recovery.
  • A higher risk for anxiety, depression and post-traumatic stress disorder.
  • Women who have had a hysterectomy will not be able to carry children in the future. This may be an additional source of anxiety and depression. It is important to know that some women who have had a hysterectomy have gone on to have more children using a gestational carrier or through adoption.

Anxiety, Depression, Post-Traumatic Stress Disorder Signs

  • Feeling persistently sad or down
  • Poor appetite
  • Difficulty sleeping
  • Difficulty caring for oneself or one’s baby
  • Difficulty bonding with one’s baby
  • Frequent thoughts, worries or nightmares about one’s baby or other loved ones experiencing harm
  • Frequent thoughts, worries or nightmares of being diagnosed with another serious condition
  • Thoughts of guilt or low self-worth

If you have these thoughts, please contact a health care professional immediately:

  • Thoughts of harming self
  • Thoughts of harming baby
  • Hearing voices or seeing things that are not there
  • Give yourself time to rest and recover after the delivery or surgery.
  • Rely on the help of loved ones to help you care for your newborn during the first months as your body recovers and regains strength.
  • Experiencing placenta accreta can be emotionally difficult for the mother, as well as for loved ones. You and your family should be aware of any signs of post-traumatic stress disorder, anxiety or post-partum depression—and seek help if needed. Learn more about services that are available for patients experiencing any of these conditions.
Obtaining Personal Help and Support

Experiencing a pregnancy with placenta accreta can be very difficult, scary and overwhelming. Women with this condition are encouraged to talk with a counselor or therapist if they feel overwhelmed, anxious or depressed. Reaching out to an obstetrician, midwife or primary care provider is an important first step when patients or family members identify these symptoms.

Placenta accreta is not common, and friends and family members often don’t know how best to help someone in this situation. Many accreta patients find help and support from other patients who have this condition or have in the past. One such organization is Hope for Accreta.

Resources and Support Services

The BWH Abnormal Placentation Program

  • Established in 2008, our team has cared for hundreds of women with uterine and placental disorders, including placenta accreta.
  • We offer accreta consultation and delivery planning, and focus on individualized care based on each patient’s particular circumstances. Additionally, access to cell salvage, autologous blood transfusion, and a hybrid operating room are available.
  • Our hospital offers 24-hour maternal fetal medicine, high-risk anesthesia, blood bank and interventional radiology coverage. Additionally, access to cell salvage, autologous blood transfusion, and a hybrid operating room is available.

In addition to delivery planning and management, we accept transfers of complicated postpartum patients and provide inter-pregnancy care, including management of retained accretas.


Emotional Support and Psychiatric Services

  • Brigham and Women’s Hospital Psychiatric Service
    Psychiatrists and social workers are available to provide immediate and ongoing support to women and couples facing stressful and high risk pregnancies. These specialists focus on the mental health needs of women throughout the reproductive life cycle including during high risk pregnancies and the postpartum period. Close coordination between maternal-fetal specialists and the psychiatry team allows women to either initiate or transfer their psychiatric care to this program if needed. Call the BWH outpatient psychiatry service for appointments at (617) 732-6753.
Support Our Work

Make a Gift

Please consider contributing to the BWH Program for Surgical Obstetrics and its Placental Abnormalities Initiative. Funds will be used to support our research programs, build communication and education tools, and make sure that our Labor and Delivery unit is equipped with state-of-the art technology to assist women who hemorrhage in childbirth. Please indicate at the time of donation that you would like to direct the funds to the Surgical Obstetric/Placenta Accreta Program.

Consider Donating Blood

Many with placenta accreta require a life-saving blood transfusion. Blood is a precious resource, and we rely on generous donors to keep our blood bank adequately stocked. Please consider scheduling a donation to help us replenish and maintain our supply of blood products for patients.

Read more about how to schedule an appointment or for more information about donating blood.

Words to Know

Cesarean Section Delivery: Delivery of a baby through an incision made in the mother’s abdomen and uterus

Cervix: The lower part of the uterus that connects to the vagina

Congenital Anomalies of the Uterus: Malformations of the uterus

Fetus: The developing, unborn baby

Gestation: The period between the conception and birth of the child

Hysterectomy: The surgical removal of the uterus

Infertility: The inability to become pregnant

Placenta: The organ that connects the developing fetus to the uterus to deliver the baby nutrients and oxygen, eliminate waste and produce hormones to support development

Placenta Accreta: A condition of pregnancy where the placenta’s blood vessels attach too deeply to the uterine wall

Placenta Increta: A condition where the placenta attaches more firmly to the uterus and becomes embedded in the organ’s muscle wall

Placenta Percreta: A condition where placenta attaches itself and grows through the uterus and potentially to the nearby organs

Placenta Previa: A condition of pregnancy where the placenta sits low in the uterus, usually over the cervix

Placental Abruption: A condition of pregnancy where the placenta disconnects from the uterus before delivery, possibly causing heavy bleeding for the mother or depriving the baby of oxygen and nutrients

Secondary Infertility: The inability to become pregnant after the birth of one or more children

Ultrasound: A type of technology that produces images of a fetus within the womb and is used for monitoring the fetus’s development

Uterus: The female reproductive organ where the fetus develops during gestation, also known as the womb

This information was made possible with a donation from the Hess Foundation.

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