Placenta accreta is a rare condition that happens during pregnancy. This condition involves the placenta, which attaches to the uterus (womb) and to the baby via the umbilical cord. During pregnancy, the placenta provides nutrition to the baby and filters waste products from the baby’s blood. In a normal pregnancy, the placenta attaches at or near the top of the uterus. After the baby is born, it releases from the wall of the uterus. It comes out of the mother’s body as afterbirth.
In placenta accreta, the placenta attaches too deeply to the wall of the uterus. According to the American Pregnancy Association, in 15 to 20% of these cases, the placenta becomes attached to the muscles inside the walls of the uterus (placenta increta). In 5% of cases, it grows all the way through the wall of the uterus (placenta percreta). If the placenta’s growth goes outside of the uterus, it can attach to nearby organs, such as the bladder.
Placenta accreta is a high-risk condition because it can cause life-threatening bleeding during labor.
Risk Factors for Placenta Accreta
Some women develop this condition without having any risk factors. But doctors know there are certain risk factors for placenta accreta. These include:
- Previous surgery on your uterus, including a c-section or dilation and curettage (D&C). According to the American College of Obstetricians and Gynecologists, women who have had more than one c-section are at the highest risk.
- Having a condition called placenta previa, where the placenta covers all or part of the cervix. Between 5 and 10% of women with placenta previa also will have placenta accreta.
- Becoming pregnant at age 35 or older.
- Having previously given birth.
- Multiple full-term pregnancies — the more births, the greater the risk.
Symptoms of Placenta Accreta
Most women who develop this condition do not have any symptoms. Some women with placenta accreta may have vaginal bleeding. If the placenta grows into the uterine wall, or even outside the uterus, a woman might experience pain as well as bleeding.
Diagnosing and Treating Placenta Accreta
Placenta accrete is sometimes diagnosed during a routine pregnancy ultrasound. However, it is not always visible on ultrasound.
Unfortunately, there is nothing that can be done to either prevent or treat this condition. If it is diagnosed during your pregnancy, your doctor will likely schedule a c-section to avoid labor. The c-section may be scheduled as early as 34 weeks.
If your doctor decides you should have an early c-section, you may have tests to make sure your baby is ready to be born. One test that can help doctors determine if your baby’s lungs are developed enough is called an amniocentesis. During amniocentesis, a doctor uses a needle to remove a sample of amniotic fluid (this is the fluid that surrounds the baby).
You may also be advised to take a corticosteroid medicine, which can help your baby’s lungs develop more quickly.
Complications from Placenta Accreta
This condition doesn’t typically affect the baby unless the mother experiences severe bleeding during her pregnancy. Severe bleeding can mean that the baby is not getting enough blood, which contains both oxygen and nutrients.
The goal in managing this condition is to make sure the expecting mother does not go into labor on her own. Doctors recommend delivery of the baby by c-section. A vaginal birth could cause the placenta to tear, causing severe and life-threatening bleeding for the mother. If the baby is still in the womb when severe bleeding begins, the baby may be deprived of oxygen. Many women with placenta accreta will need to have a hysterectomy right after the baby is delivered. In a hysterectomy, the uterus is removed, meaning that the woman will not be able to carry additional pregnancies.