Bleeding can happen at any time during pregnancy. Placenta previa can cause bleeding late in pregnancy. This means after about 20 weeks.
When the placenta is attached close to the opening of the uterus (cervix) or covers the cervix, it is called placenta previa. There are 3 types of placenta previa:
Doctors don't know what causes placenta previa. It is more likely to happen with certain conditions. These include:
The most common symptom of placenta previa is bright red, painless bleeding from the vagina. This is most common in the third trimester of pregnancy.
The symptoms of placenta previa may look like other health conditions. Make sure to see your healthcare provider for a diagnosis.
Your doctor will ask about your health history. He or she will do a physical exam. The provider will also do an ultrasound. An ultrasound uses sound waves to make a picture of the organs. It can show where the placenta is and how much is covering the cervix. You may have a transvaginal ultrasound instead.
An ultrasound may show that a placenta is near the cervix in early pregnancy. But, only a few women will develop true placenta previa. It is common for the placenta to move away from the cervix as the uterus grows.
There is no treatment to change the position of the placenta. You may need:
The greatest risk of placenta previa is too much bleeding (hemorrhage). Bleeding often happens as the lower part of the uterus thins during the third trimester of pregnancy. This causes the area of the placenta over the cervix to bleed. The risk of bleeding is higher if a lot of the placenta covers the cervix. Other complications include:
Call your healthcare provider about any bleeding you have while pregnant. Bleeding during pregnancy may not be serious. If the bleeding is moderate to severe, or you have pain, contact your healthcare provider right away.
Tips to help you get the most from a visit to your health care provider: