Placenta Accreta

Placenta accreta at a glance

  • Placenta accreta is a high-risk pregnancy complication that occurs when the placenta is abnormally attached to a woman’s uterus.
  • This can lead to massive blood loss following delivery as well as increase the likelihood of preterm delivery.
  • Placenta accreta is linked to abnormalities in the lining of the uterus, typically due to scarring from a previous C-section delivery or other uterine surgery.
  • Advances in imaging and testing enable obstetricians to diagnose the condition early, usually during a routine ultrasound.
  • If obstetricians suspect placenta accreta during a pregnancy, the patient will likely need an early C-section delivery followed by the surgical removal of the uterus (hysterectomy).
  • Surgery outcomes are better when using a gynecologic oncologist or other surgeon specially trained in treating women’s reproductive issues.
  • The University of Colorado has the region’s only placenta accreta program.

What is placenta accreta?

Placenta accreta is a condition in which the placenta grows too firmly into a woman’s uterine wall, sometimes resulting in part or all of it remaining attached to the uterus after delivery. This can cause serious complications such as premature labor, abnormal or heavy bleeding during pregnancy and hemorrhaging after delivery. Hemorrhaging can cause life-threatening conditions including one that prevents blood from clotting normally (disseminated intravascular coagulopathy) or lung and kidney failure.

During pregnancy a woman develops the placenta organ to provide oxygen and nutrients to a baby, as well as to remove waste from a baby’s blood. During delivery the placenta typically detaches from the uterine wall as part of the afterbirth. Placenta accreta is the term used when the placenta doesn’t detach because it has invaded and attached itself to the uterine wall.

Approximately 1 in 530 pregnancies experience placenta accreta or the related conditions increta and percreta. The differences between placenta accreta, increta or percreta involve how severely the placenta is attached to the uterine wall.

Placenta accreta is the most common and refers to the placenta attaching itself into the lining of the uterus. The more severe condition of placenta increta refers to the placenta attaching itself even more deeply into the muscle wall of the uterus. Finally, placenta percreta is when the placenta attaches itself and grows through the uterus, sometimes extending into or around other organs such as the bladder.

Women diagnosed with placenta accreta work with their obstetrician and team to develop a delivery plan that minimizes risk to the baby and mother. The delivery plan sometimes includes a cesarean hysterectomy (removal of the uterus after a C-section).

In less severe cases, surgical management may be an option. This can involve leaving either the entire placenta or adherent portions, with the hope it may detach itself later.

While often diagnosed early in a pregnancy, sometimes physicians discover the condition late in the pregnancy or during delivery if the placenta is not part of the afterbirth. In these rare cases, the delivering obstetrician may involve an emergency team for treatment that may include blood transfusions and surgery.

Causes of placenta accreta

While the exact cause of placenta accreta is unknown, according to the American Congress of Obstetrics and Gynecology (ACOG), the incidence has increased and is strongly linked to the rise in C-section deliveries. Women who have had multiple C-sections have a higher risk of placenta accreta. Other risk factors for developing placenta accreta include:

  • Placenta position: If the placenta partly or completely covers the cervix (placenta previa) or sits low in the uterus, there is a higher chance of developing placenta accreta.
  • Age: Women who are 35 or older are more likely to develop placenta accreta.
  • Previous childbirth: The risk of placenta accreta grows each time a woman gives birth.
  • Multiples: Being pregnant with two or more babies.
  • Previous uterine surgery or conditions: Women who have had uterine surgeries (including those to remove fibroids or other growths) have a significantly higher risk. Uterine scarring, from these surgeries or otherwise, also increases the chance the placenta will adhere to the uterine lining after delivery.
  • Noncancerous uterine growths: Those that protrude into the uterine cavity (submucosal uterine fibroids) or are otherwise abnormal.

Placenta accreta symptoms & diagnosis

Placenta accreta often presents no signs or symptoms during pregnancy, with the exception of the possibility of vaginal bleeding during the third trimester.

Early diagnosis is key to curbing risks during delivery and developing a treatment plan to minimize threats to both mother and baby. Obstetricians carefully examine women throughout their pregnancy using a variety of methods including:

  • Ultrasound – typically placenta accreta is discovered during a routine ultrasound that uses sound waves to look inside the body.
  • Magnetic resonance imaging (MRI) – uses magnetic fields to look inside the body and can show a physician if the placenta has grown into the uterine wall, detecting the location and density of the growth.
  • Blood tests – check for high levels of alpha-fetoprotein, a protein produced by the baby that is detected in the mother’s blood. In recent years, high levels of alpha-fetoprotein have been linked to causing placenta accreta.

Treating placenta accreta

Treating placenta accreta most typically involves a cesarean hysterectomy performed by a pelvic surgeon such as a gynecologic oncologist who specializes in women’s reproductive surgeries. The cesarean is typically scheduled at 34-36 weeks to balance the health of the mother and baby.

Once placenta accreta is diagnosed, appropriate planning and preparation by a multidisciplinary delivery team, which may comprise an obstetrician, anesthesiologist, blood bank and surgeon, is especially important because of the high risk of massive hemorrhaging during delivery or surgery. However, with proper care and planning the vast majority of women safely deliver healthy babies.

Treatment depends heavily on the severity of the case, and sometimes that is not known until the cesarean operation gets underway. Prior to her scheduled delivery, the patient and delivery team must discuss all treatment options along with the woman’s desire to have additional children.

In less severe cases, a woman may not require a cesarean hysterectomy and a skilled surgeon may opt to leave portions of the placenta, with the hope it may detach itself later.

According to ACOG, the limited amount of research indicates that women who have placenta accreta and do not have a hysterectomy after have a greater risk of complications in future pregnancies. This includes possible miscarriage, premature birth and recurrent placenta accreta.

Possible complications after cesarean hysterectomy are typical of any surgery or C-section. These include risk of infection, bleeding, fever, scarring and urinary tract injury.

The only placenta accreta program in the region

The University of Colorado’s placenta accreta program is the only one in the region. It has a team of surgeons, led by gynecologic oncologist Dr. Saketh Guntupalli, who are dedicated to the management of placenta accreta and can provide highly skilled surgical management for this complex condition.

University of Colorado Gynecologic Oncology utilizes a multi-functional operating room with planned patient care to offer patients the most comprehensive care for a complicated diagnosis. A multidisciplinary team of anesthesia, radiology, pediatric, urology and interventional radiology specialists is available for every surgery.