What is placenta accreta?
Placenta accreta is a condition in which the placenta (the food source for a baby in the uterus) grows too deeply into the wall of the uterus. In a typical pregnancy, the placenta easily detaches from the wall of the uterus following delivery. In placenta accreta, the placenta has grown into the uterine wall and does not separate easily following delivery. In severe cases, this condition can lead to excessive bleeding, which can be life-threatening. It can require a blood transfusion and even hysterectomy (removal of the uterus).
What are the different types of placenta accreta?
There are three types of this condition. The type is determined by how deeply the placenta is attached to the uterus.
- Placenta accreta: The placenta firmly attaches to the wall of the uterus. It does not pass through the wall of the uterus or impact the muscles of the uterus. This is the most common type of the condition.
- Placenta increta: This type of the condition sees the placenta more deeply imbedded in the wall of the uterus. It still does not pass through the wall, but is firmly attached to the muscle of the uterus.
- Placenta percreta: The most severe of the types, placenta percreta happens when the placenta passes through the wall of the uterus. The placenta might grow through the uterus and impact other organs, such as the bladder or intestines.
What are the risks to the mother and baby from placenta accreta?
The risks of placenta accreta can be serious and can expand beyond the mother to the newborn. Once born, the baby may be at additional risk because of a premature birth. Risks for the mother can include:
- Premature delivery
- Damage to the uterus and surrounding organs
- Loss of fertility due to the need for a hysterectomy (removal of uterus)
- Excessive bleeding that requires a blood transfusion
What leads to placenta accreta?
Placenta accreta is thought to be caused by scarring or other abnormalities with the lining of the uterus. Several risk factors have been linked to placenta accreta, including:
- Multiple **cesarean sections (c sections)**: Women who have had multiple cesarean sections have a higher risk of developing placenta accreta. This results from scarring of the uterus from the procedures. The more cesarean sections a woman has over time, the higher her risk of placenta accreta.
- Placenta previa: This condition occurs when the placenta is located at the bottom of the uterus, blocking the opening of the cervix. The lower part of the uterus is less suited for the placenta to implant. In patients with placenta previa and a history of prior cesarean section(s), the risk for placenta accreta increases with the number of cesarean sections the patient has had.
- History of fibroid removal: If the woman has had a fibroid (a not cancerous growth or tumor of the uterine muscle) removed, the scarring could lead to placenta accreta.