Placenta previa is a condition in which the placenta of pregnant women, implants and covers, covers part or near the throat of his wife. The  before  to  preview  simply means  before  - the placenta before the baby is placed. This condition affects 1 in 200 pregnant women and unborn babies. In most cases of placenta previa, because the uterus and growing baby, the placenta is above and beyond the cervix and not cause other problems. They often follow if placenta previa in the first quarter suspected ultrasound, ultrasound-up will have to determine that the placenta has moved. If your doctor has placenta previa reported as possible, and be the first or second quarter, not to worry.
Type I or low lying: The placenta lies low in the uterus but does not extend to an area of the neck.
Type-2-or marginal: The placenta touches, but not the neck.
Type 3 or partial: The placenta partially covers the cervix.

What are the symptoms?
Improper location of the placenta is painless, bright red, can cause bleeding too light or too heavy. Bleeding after 24 weeks of pregnancy to placenta previa, your doctor may suspect. Ultrasound is often used to confirm the diagnosis.