Picture of normal placenta and placenta previa

Normally, the placenta is attached to the uterus above 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 Anne Marshall, MD - Family Medicine
Specialist Medical ReviewerWilliam Gilbert, MD - Neonatal-Perinatal Medicine
Last RevisedFebruary 23, 2010

© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.