Topic Overview

During pregnancy, the placenta is normally attached to the upper wall of the uterus. A placenta that develops low in the uterus without overlapping the cervical opening is referred to as a low-lying placenta. A low-lying placenta is not a high-risk condition and often resolves as the pregnancy progresses.

If you have a low-lying placenta early in pregnancy, there is a good chance that as the lower uterus enlarges, the placenta's relative position will shift away from the cervix. But when the placenta does overlap the cervix, it is called placenta previa, which can bleed heavily during labor. Fortunately, about 90% of placenta previa cases diagnosed before the 20th week no longer overlap the cervix by the end of the pregnancy.¹