The placenta also acts as a barrier since its vital that germs in your body dont make your baby sick and also that your body doesnt reject your baby as foreign material so at the same time the placenta allows blood cells and nutrients through it keeps most but not all bacteria and viruses out of the womb it also prevents many of . Placenta increta representing 15 to 17 of placenta accreta cases this form of the condition is when development of the placenta is within the uterine wall and it penetrates the myometrium childbirth is severely impacted in these cases since this can lead to severe hemorrhage due to retention of the placenta within the body as such cesarean delivery is required alongside hysterectomy or . Placenta previa is the attachment of the placenta to the wall of the uterus in a location that completely or partially covers the uterine outlet opening of the cervix bleeding after the 20th week of gestation is the main symptom of placenta previa an ultrasound examination is used to establish the diagnosis of placenta previa treatment of placenta previa involves bed rest and limitation . Placenta accreta is a serious pregnancy condition that occurs when the placenta grows too deeply into the uterine wall typically the placenta detaches from the uterine wall after childbirth with placenta accreta part or all of the placenta remains attached this can cause severe blood loss after delivery