title: Ultrasonic diagnosis of low implantation preceding placenta previa.
mesh_terms: D002585:Cesarean Section; D010064:Embryo Implantation; D005260:Female; D006801:Humans; D010923:Placenta Previa / Q000175:diagnosis*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014463:Ultrasonography