The placenta is an organ that grows inside a mother’s uterus during pregnancy to nourish the baby. The placenta connects to the baby via the umbilical cord and typically attaches to the top or side of the uterus. It provides oxygen and nutrients to your baby and removes a baby’s waste. Placenta accreta is a serious condition of pregnancy where the placenta has attached too deeply to the mother’s uterine wall. There are various types of placenta accreta, with some being more severe than others.
Placenta accreta is problematic because it leads to two major complications. The first is that the placenta does not deliver normally after the baby is born because part or all of it is still attached inside a mother’s uterus. The second complication is that the process of removing the placenta can lead to hemorrhaging (severe bleeding) for the mother.
With the help of a team of experts, situations involving placenta accreta can be managed successfully. In some cases, blood transfusions, cesarean sections, special surgeries, and a possible hysterectomy (removal of the uterus) are necessary to ensure the mother and baby’s health is maintained. Obstetricians try to diagnose this condition during pregnancy using ultrasound or MRI imaging. But sometimes, placenta accreta is not discovered until actual delivery begins.
Placenta Accreta Types
There’s a spectrum of severity with three main categories:
- Placenta Accreta: the placenta attaches deeper than normal, ranging from small accretas called “focal accretes” to larger ones.
- Placenta Increta: the placenta attaches deep enough that it becomes embedded in the uterine muscle.
- Placenta Percreta: the placenta attaches so deeply it becomes attached to organs beyond the uterus, like the bladder.
- Placenta Previa: this is not a form of accreta but may coincide with it. This condition happens when a low-lying placenta covers the cervix.
According to the American College of Obstetricians and Gynecologists, rates of placenta accreta spectrum are increasing. A 2016 study of women in the United States who had a birth-related hospital discharge diagnosis found the overall rate of this condition was 1 in 272. This rate was greater than any other previously published study on the topic.
Several risk factors contribute to a woman’s chance of developing placenta accreta. Risk factors include:
- Previous uterine surgery. Past uterine surgery (or surgeries), including a cesarean delivery (C-section), surgery to remove uterine fibroids, or surgeries near the uterus.
- Placenta position. Placenta previa is a condition in which the placenta partially or fully covers the cervix. This indicates a low-lying placenta.
- Maternal age. It is more common in women over the age of 35.
- Previous births. Prior childbirths increase your risk for placenta accreta.
- Uterine abnormalities. Scarring or uterine fibroids increase your risk.
Symptoms of Placenta Accreta
Placenta accreta can cause vaginal bleeding, particularly in the third trimester. It often does not show signs but can be detected via ultrasound. If you’ve had multiple C-sections or surgery on or near your uterus, tell your doctor early on. These can be potential risk factors for the development of placenta accreta. Sometimes placenta accreta is not detected until actual childbirth is underway.
Causes of Placenta Accreta
The exact cause of placenta accreta is unknown, but researchers believe that scarring in the uterine wall from prior cesarean sections or other uterine surgeries may play a role in advancing this irregularity.
According to the American Pregnancy Association, women who’ve had more than one C-section delivery account for 60% of all placenta accreta cases. Cases have also been linked to high alpha-fetoprotein levels, a protein made by the fetus that can be detected in a pregnant mother’s blood.
Complications for Mother
The primary concern for the mother is hemorrhaging. Hemorrhaging can occur when the placenta is manually operated on to remove it from the uterine wall or other organs it grew into. A hysterectomy to remove the uterus entirely may be necessary, but the results mean a mother cannot conceive afterward.
Complications for Baby
The primary concern for the infant is premature delivery and subsequent complications.
Treatment plans will vary from mother to mother, depending on the severity of their condition. In some cases, women may need bed rest several weeks before delivery. Early delivery and/or a C-section may also be scheduled. In severe cases of placenta accreta or risk of hemorrhaging, a hysterectomy may be needed.
According to the American College of Obstetricians and Gynecologists, choosing to deliver in a maternity center with highly experienced staff who have a coordinated care team that can provide additional expertise and resources in case of a mother’s severe hemorrhaging appears to improve the overall outcome.
Work with your doctor, midwife, or healthcare team to determine the most advanced hospital or center you can deliver your child in and determine the best path forward for managing your placenta accreta. Talking regularly with a therapist, doula, or counselor can also be a great way to relieve stress and manage your emotions.
Unlike other conditions related to pregnancy, placenta accreta cannot be prevented. If you are experiencing any of the above symptoms, be sure to tell your doctor right away.