Normally, the placenta is attached to the uterus away from the cervix. When
the placenta blocks the cervix, it is called placenta previa. The amount
of cervix covered by the placenta may be slight (marginal), moderate (partial),
or complete (total). This picture shows a complete placenta previa.
ByHealthwise Staff Primary Medical ReviewerSarah Marshall, MD - Family Medicine Adam Husney, MD - Family Medicine Specialist Medical ReviewerWilliam Gilbert, MD - Maternal and Fetal Medicine