Placenta Previa is a condition where the placenta attaches near the bottom of the uterus, rather than its normal location at the top.
The primary symptom of Placenta Previa is passing blood in small or large amounts.
Placenta Previa can be identified or confirmed during an ultrasound.
If it is a true Placenta Previa, one that stays attached at the bottom, then a cesarean will be necessary to deliver the baby.
However in most cases, as the uterus grows in size, the attached placenta will migrate up, following the expansion of the uterus wall. An ultrasound later in pregnancy, closer to the due date, can confirm this and make it clear that a vaginal birth is possible.
The primary treatment for Placenta Previa is bed rest. This is to prevent the placenta from dislodging or separating from the uterus wall.
If the placenta does become detached, the baby will need to be delivered right away. The intention behind bed rest is prevent a premature birth, and for the mother to hold the baby inside to full term if possible.
It is estimated that about 5%, or 1 out of 200 pregnancies, will have a placenta that is attached in a location that would be regarded as low at 20 weeks. Of these 5%, a far smaller number will have a placenta that truly blocks the birth canal at 39 weeks when the pregnancy is at full term.