placenta previa

painless late trimester bleeding with ultrasound dx.
risk factors: multiparity, advanced maternal age
risk of placenta accreta --> C section hysterectomy, Sheehan's, ATN.

management: emerge C section - if mom or fetus in jeopardy, scheduled C section - 36 wks when lung maturity confirmed by amnio, vaginal delivery - if placental edge is > 2cm from os, conservative watch - bed rest if remote from term, replace blood loss if needed.