Facts and Myths: Placenta Accreta

Placenta accreta is an uncommon and complex condition. Accreta patients, along with their friends and family, may receive inconsistent information about the condition and its consequences.

To begin with, it is important to understand the meaning of the terms accreta, increta and percreta. The terms can be confusing so before we turn to the myths, here are the definitions:

  • 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 is a serious condition that can cause complications for the baby and mother, especially during the delivery.
  • 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.

The following are commonly believed myths submitted by women who have experienced placenta accreta first-hand. The surgical obstetrics specialists at Brigham and Women’s Hospital have addressed each of these points based on current medical information and practice.

Myth: Women with placenta accreta always hemorrhage at the time of delivery.

Fact: Women with accreta are certainly at high risk for bleeding and hemorrhage, which is why expert care is needed. However, accreta can occur in a wide range of circumstances and not every woman will hemorrhage.

The likelihood of a hemorrhage depends on the individual conditions of your placenta. During pregnancy, bleeding and hemorrhage is more related to placenta previa (placenta covering the cervix) than to the accreta. With a previa, large blood vessels around the cervix may bleed in response to contractions, or bleed on their own, though most women with a previa do not hemorrhage. An accreta that develops without previa would be less likely to bleed.

The risk also may be related to how the placenta is treated at the time of delivery. When delivering a baby from a uterus with an accreta, particular care is given to where the incision is made. Many women with accreta will have an up-and-down incision so as to deliver the baby without disturbing the accreta. If the accreta is low in the uterus, which is usually the case, this incision allows a safe delivery above this area.

Once the baby is delivered and the accreta is confirmed, trying to remove it can also create severe bleeding. Therefore, it is usually left in place and a hysterectomy is performed to avoid a major hemorrhage. In some cases the placenta may be removed or left behind without a hysterectomy, but only with special precautions to avoid hemorrhage. This is not a common practice.

In some cases, a hemorrhage is highly likely or even inevitable, but this is not true for all women with accreta. No matter the hemorrhage risk, it’s important that well-trained obstetricians who understand your specific needs and risks manage your baby’s delivery.

Myth: All women diagnosed with accreta must have a hysterectomy after delivery.

Fact: A hysterectomy is a highly effective treatment for minimizing hemorrhage, but is not always necessary. In general, large accretas, incretas and percretas are most safely managed with a hysterectomy. However, small or “focal” accretas can sometimes be removed without a hysterectomy. In other cases, patients and their doctors may agree that leaving some or all of the accreta in the uterus (rather than removing the uterus) is a reasonable option. These decisions are complicated and require extensive discussion with an experienced obstetrician.

Myth: Women with accreta will not bleed because the accreta holds the uterus and placenta together.

Fact: There are different reasons why women bleed before giving birth. The most serious cause is placental abruption, a condition where the placenta separates from the uterus early and bleeding occurs behind the placenta. It’s possible, although rare, for a woman with accreta to experience an abruption.

The more common cause for bleeding in accreta patients is placenta previa. In this case, the placenta is sitting in an abnormally low position, and this causes the blood vessels connecting the uterus and placenta to bleed. Patients with accreta often also have placenta previa. The previa may bleed even though the placenta is tightly attached to the uterus.

Myth: If a woman with placenta accreta does not experience bleeding, this means it’s safe to carry the baby to term. In other words, “no bleeding, no problems.”

Fact: The majority of women with placenta accreta need to deliver weeks before their due dates, even if there has been no bleeding. This is often the best option for a controlled delivery, where all risks can be managed safely. If a woman experiences heavy bleeding, an earlier delivery may be especially important.

Delivery with accreta requires a very complex surgery, often with a multidisciplinary team of surgeons. Therefore, it is best to deliver your baby as soon as it is safe to do so, both in terms of the baby’s health and the mother’s wellbeing. Typically, this occurs at week 34 of gestation (6 weeks before the due date) and no later than week 36-37 of gestation. However, this depends on your specific conditions. For example, a patient who appears to have a percreta may be delivered earlier than a patient with no signs of this. On the other hand a patient with a small (“focal”) accreta and no previa may be delivered at 37 weeks or later.

Myth: All accreta patients must be under general anesthesia for either part or all of the delivery and hysterectomy.

Fact: The anesthesia required for delivery depends entirely on your individual circumstances. For women who require a long, complicated surgery, or who hemorrhage, general anesthesia may be necessary for safety and comfort. However, an epidural anesthetic will often be used at the beginning of the surgery to allow the patient to be awake for the baby’s delivery. Often the entire surgery can be performed with the epidural instead of general anesthesia.

Myth: A vaginal delivery is not possible with accreta.

Fact: Many, if not most women with accreta also have placenta previa, have had a previous cesarean section, or both. A placenta previa always requires a cesarean section because the placenta is covering the cervix. Similarly, it is usually safest for women with accreta who have had a previous cesarean section to deliver their baby via cesarean again. This is especially true if the placenta is attached to the scar from the previous cesarean. Women who labor after a prior cesarean section are at risk for uterine rupture. The safety of labor with a placenta invading a cesarean section scar has never been evaluated, and the risk of rupture and major hemorrhage may be higher in this situation.

If you do not have a placenta previa, you may be able to deliver vaginally. However, this delivery may be complicated and is at a higher risk for hemorrhage. It is important to talk to an obstetrician with experience in this area before deciding on a vaginal versus cesarean delivery.

Myth: Placenta accreta and retained placenta always occur simultaneously.

Fact: Most women with placenta accreta will have a retained placenta (a piece of the placenta that stays in the uterus after delivery). This occurs because the accreta has grown deeply into the uterus and will not separate.

Many women without accreta experience a retained placenta. In fact, many women experience a placenta that is slow to separate from the uterus (usually after a vaginal delivery) or a placenta that won’t deliver and needs to be removed by hand. Retained placenta and accreta do not always go together.

Myth: It is impossible to have accreta if I have never had a cesarean section before.

Fact: While a previous cesarean section is one of the strongest risk factors for accreta, there are other circumstances that can lead to accreta even without a previous cesarean. These include other types of surgery on the uterus (such as removal of fibroids or scar tissue), placenta previa, older maternal age and in vitro fertilization (IVF). Fortunately, the vast majority of patients with any of these risk factors will never experience an accreta. However, women who have placenta previa or more than one risk factor should be carefully checked for accreta.

Myth: An accreta can always be detected on an ultrasound or MRI image before delivery.

Fact: An ultrasound or MRI image can usually detect an accreta, but not always. For example, an ultrasound or MRI may detect increased vascularity (or blood flow) beyond the parameters ordinarily seen. That could be evidence of a possible accreta. A pregnant uterus, however, always has extra blood flow to some degree. This makes interpreting ultrasound and MRI images particularly challenging. Having images reviewed by a radiologist and obstetrician that are experienced in identifying accreta cases is important, although even then there can be some uncertainty in diagnosis. Currently, researchers are trying to develop blood tests that will help make accreta diagnoses more accurate. For now, women at high risk for accreta should deliver with a team of experienced doctors prepared to manage an accreta and possible hemorrhage, even if accreta was not detected on the ultrasound or MRI.

Myth: Women are not able to breastfeed after a cesarean and hysterectomy.

Fact: This is not the case. Some women who have a very complicated surgery and recovery will not be able to breastfeed, and their babies will develop healthfully with formula or donated breast milk. However, even after a hysterectomy or hemorrhage a mother can try to breastfeed. It is possible that the breast milk may take longer to come in given the complexity of the surgery, but women who wish to breastfeed should be supported in doing so.

At Brigham and Women’s Hospital, patients are encouraged to breastfeed after a hemorrhage or hysterectomy if they feel up to it, and some have started pumping even while in intensive care.

Resources and Support Services

The BWH Program for Surgical Obstetrics

  • 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.
  • 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 are 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.

Consults

  • Schedule a consultation with a Brigham and Women’s Obstetrician Specializing in Placenta Accreta.
  • For patients with placenta accreta who have questions or are seeking another opinion contact the Partners Online Specialty Consultations.

Psychiatric Services

Psychiatrists are available to provide immediate and ongoing support to women and couples facing stressful and high risk pregnancies. 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. Learn more about this service.

Hope for Accreta

  • Hope for Accreta offers information and support for women with placenta accreta.
  • Find a local chapter to meet with other women in your area.
  • Thank you to Sophia Watson and the women of the Hope for Accreta Foundation, who contributed myths and feedback for this site.

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

 

LEARN MORE ABOUT BRIGHAM AND WOMEN’S HOSPITAL


For over a century, a leader in patient care, medical education and research, with expertise in virtually every specialty of medicine and surgery.

About BWH