OverviewPlacenta previa is a condition of pregnancy when the placenta implants in the lower part of the uterus, partly or completely obstructing the cervical outlet to the vagina (birth canal).
Update Date 7/28/2014
Updated by: Cynthia D. White, MD, Fellow American College of Obstetricians and Gynecologists, Group Health Cooperative, Bellevue, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.