Is there anything you can do to help a placenta previa—massage, exercises, etc.?
Placenta previa occurs when the placenta either partially or completely covers the internal opening to the cervix, obstructing the baby's path for birth. Placenta previa can lead to heavy vaginal bleeding as the cervix starts to open, and may require a Cesarean birth. The diagnosis of placenta previa is usually made by ultrasound. Complete placenta previa means that the placenta totally covers the opening. Partial previa indicates that the placenta will be partially exposed once the cervix dilates.
The good news is that placenta previa discovered early in pregnancy often resolves before it can cause any problems. As the uterus grows, the placenta is pulled away from the cervix, leaving a clear path for the baby to come through. Partial previas are more likely to resolve than complete previas are, but I have seen what was believed to be a complete placenta previa move away before the baby's birth. If placenta previa persists into the late third trimester, it is unlikely to resolve.
Your question is a good one—what can you do to help the placenta move to a better location? Unfortunately, there are no positions, medications, or manipulations that are known to resolve placenta previa, and based on the physiology, one wouldn't expect any sort of treatment to make any difference. Still, it is reasonable to continue to hope that the placental position will improve, since that is often the case. Good luck!