, the placenta moves as the uterus stretches and grows. It is very normal
for the placenta to be low in the uterus in early pregnancy. But as the pregnancy continues, the placenta typically moves to the top of the uterus. By the third trimester, the placenta should be near the top of the womb, so the cervix has a clear path for delivery
. If the placenta attaches to the lower part of the uterus, it can cover part or all of the cervix (the entrance to the womb). When the placenta covers part or all of the cervix during the last months of pregnancy, this is a condition known as placenta previa, or low-lying placenta. This condition can cause severe bleeding before or during labor.