During a baby’s development, the placenta is attached to a layer of the uterus that is shed during birth. With placenta accreta spectrum, the placenta grows too deeply into the uterine wall during pregnancy and can’t detach during delivery. Placenta accreta is a spectrum because it has three different levels, ranging from least to most severe:
- Placenta accreta: the placenta grows too far into the uterine wall
- Placenta increta: the placenta grows beyond the uterine wall and attaches to the uterine muscle
- Placenta percreta: the placenta grows beyond the uterine wall and muscle, sometimes reaching other organs
Placenta accreta spectrum can cause significant complications during delivery, including excessive bleeding and prolonged hospital stays, and can be life-threatening to the mother. As the rate of cesarean deliveries has increased in the U.S., so has the rate of placenta accreta, which has quadrupled since the 80s.