Placenta accreta is an abnormally firm and deep attachment of the placenta to the uterine wall. It’s actually an umbrella term for three variants, depending on how deeply the placental cells invade:
- Placenta accreta: The placenta digs deeply into the uterine wall but does not pierce the uterine muscles. This is by far the most common condition, accounting for 75 percent of all cases.
- Placenta increta: In 15 percent of cases, the placenta pierces through the wall to the uterine muscles (or myometrium).
- Placenta percreta: In 10 percent of cases, the placenta burrows into the uterine wall and its muscles, then pierces the outer part of the wall. It may even attach itself to other nearby organs.
How common is it?
This attachment abnormality occurred in one out of 533 pregnancies as of 2002. The American Congress of Obstetricians and Gynecologists (ACOG) notes that the rate appears to be climbing as the rate of cesarean sections has increased.
What’s the cause?
Experts believe placenta accreta is related to abnormalities in the uterine wall, usually due to previous uterine surgery.
Who’s at risk?
Your risk of this condition increases if you have:
- Placenta previa
- Undergone uterine surgery
- Delivered by C-section (your risk increases with each cesarean delivery)
- A “high risk pregnancy” (are 35 years or older or are pregnant with multiples)
What are the symptoms and how is it diagnosed?
There are usually no apparent symptoms — but if you have risk factors, your doctor will know to keep an eye out for the condition; it’s usually diagnosed via ultrasound but sometimes requires an MRI. Sometimes, however, it is only noticed during delivery, when the placenta doesn't detach (as it normally would) from the uterine wall after the baby is born.
Should you be concerned?
Placenta accreta increases the risk of heavy bleeding or hemorrhaging during delivery. If you have placenta percreta, your bladder or other nearby organs may be damaged by the grip the placenta has on them.
For your baby, the most significant risk posed by placenta accreta is that it might trigger or require a preterm delivery.
What you can do
Unfortunately, there is little you can do before birth. If placenta accreta is diagnosed during pregnancy, you may be placed on bed rest to help ensure you carry your baby to term. Your doctor will also likely recommend that you plan to deliver at a specialized facility, with an experienced team including an obstetric surgeon who can better monitor you and manage complications.
What happens during delivery
ACOG recommends delivering the baby by C-section and removing the entire uterus several weeks in advance of your due date (planned preterm cesarean hysterectomy) while leaving the placenta in place to minimize your risk of severe bleeding and other complications. However if you’d like to have more kids let your practitioner know; he will discuss whether it’s safe for you to attempt vaginal delivery. Then once you give birth, he’ll attempt to remove part of the placenta to stop the bleeding, leaving your uterus in place. If you do try to keep your uterus, ACOG warns there is an increased risk of significant complications, your chances of having a successful pregnancy again are greatly reduced, and you may still require a hysterectomy.
It’s normal to feel overwhelmed by a placenta accreta diagnosis, especially if you were planning to have more kids but need a hysterectomy, so talk to your doctor about what’s best for you and why. Try to remind yourself that it’s the best choice to reduce your chances of complications — so you can focus on enjoying the beautiful new bundle of joy you’ve brought into the world.
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