A low-lying placenta is when the edge of the placenta is very close to the cervix, that is, between 1-20 mm from the internal os. While a low-lying placenta is not always concerning, it can increase the risk of bleeding, which can cause complications for the pregnant person and and fetus.

Painless, bright-red vaginal bleeding can be a sign of a low-lying placenta, and may happen with sex or during labor.

A low-lying placenta usually resolves on its own, migrating further away from the cervix as the pregnancy progresses, however it is important to monitor a low-lying placenta with your obstetric provider. This usually involves the use of ultrasound exams to confirm the location of the placenta at different points in the pregnancy.

Potential risks

Having a low-lying placenta can be risky, especially if the placenta remains low lying by the end of the pregnancy. This is because a low-lying placenta can increase the risk for heavy bleeding (hemorrhage), which can be potentially life-threatening.

While a low-lying placenta does not cover the cervix, and a vaginal birth is possible, the risk of a hemorrhage during labor leading to an emergency cesarean section (c-section) is higher than in women without a low-lying placenta.

Low-lying placenta can increase the risk for premature birth, which can lead to neonatal complications low birth weight and respiratory distress at birth.

Common symptoms

A low-lying placenta can cause vaginal bleeding, which is more common in the second or third trimester of pregnancy. The bleeding is typically painless and can happen from sex or during labor.

It is important to seek urgent medical care for vaginal bleeding during pregnancy so that the cause of the bleeding can be identified and managed appropriately.

Confirming a diagnosis

The diagnosis of a low-lying placenta is confirmed on obstetric ultrasound, sometimes as early as the first trimester.

When the placenta is low-lying, it is usually recommended to repeat an ultrasound at other points in pregnancy to confirm that the placenta is still low lying.

Treatment options

A low-lying placenta tends to grow upward and away from the cervix as the pregnancy advances, with no special treatment needed.

In the event that the placenta remains low lying, a c-section is typically recommended, especially if the edge of the placenta is very close to the cervix or causes heavy bleeding.

When will a low-lying placenta resolve?

A low-lying placenta usually resolves itself by 24 weeks of pregnancy.

Care instructions

In the case of a low-lying placenta, special precautions include:

Avoiding strenuous physical activity;
Avoiding sex;
Seeking urgent medical attention in the case of any vaginal bleeding.

In addition, it is important to talk to your obstetric provider about your risks in order to plan for the safest mode of delivery (vaginal vs cesarean birth). A cesarean delivery may be recommended in some cases.