Normally, the placenta is attached to the inside of the uterus, along the side or the top of it. Placenta previa occurs when the placenta is attached near the bottom of the uterus, and either partially or completely blocks the opening of the cervix. Common symptoms from this are bleeding in the later stages of pregnancy, usually with no pain or uterine contractions.
When placenta previa is diagnosed earlier in the pregnancy, which is possible using ultrasound, it is monitored very closely.
Why does placenta previa become serious if a normal vaginal delivery is attempted? As the cervix dilates, it usually causes the placenta to separate from the wall of the uterus too early, resulting in serious bleeding that can be fatal for the mother and/or the baby. Because of this, cesarean delivery is usually recommended.
Placenta previa happens in about 1 out of 200 pregnancies. But some women are at higher risk of developing it. These include women who:
· Have already had at least one previous c-section,
· Have had several other pregnancies,
· Have another surgical scar on their uterus,
· Had placenta previa in a previous pregnancy,
· Are over the age of 35, or
· Use tobacco products or other drugs such as cocaine.