Placenta Previa occurs when the placenta lies at the bottom of the uterus, covering the cervix and blocking your baby’s exit passage. It has implanted wrong. Normally it is attached up high in the uterus, not low-lying. An ultrasound will confirm placental location. The placenta begins to prematurely separate when the cervix begins to dilate & efface. The placenta will come out first, so this will not be a normal delivery. The most common sign is bright red painless bleeding, whi