ABSTRACT
PLACENTA PREVIA Diagnoses/Definitions Placenta previa is defined as a placenta that covers the internal os. The diagnosis of placenta previa is established by TVU. The terms partial, marginal, complete, or incomplete placenta previa are rooted in preultrasound physical examinations, have been used to signify different conditions, and therefore should be avoided. Moreover, many studies have used these terms to signify different conditions. When the placenta does not cover the internal os, rather than use ambiguous language, it is best to describe the distance of the tip of the placenta from the internal os. Low-lying placenta is defined as a placenta that comes within 0.1 to 2.0 cm of the internal os but does not cover it.
