The placenta in the womb of a pregnant woman diagnosed with placenta previa lies at an abnormal low position in the uterus. Normally the placenta is located on the upper part of the uterus.
The placenta supplies nourishment to the fetus developing in the womb, which reaches the fetus through the umbilical cord that connects the fetus to the placenta. In placenta previa, the placenta might cover the cervix either partially or completely.
Types of placenta previa
There are four types or degrees of placenta previa. In total placenta previa, the placenta covers the opening of the cervix completely. If the placenta partially covers the cervical opening, it is known as partial placenta previa. Marginal placenta previa occurs when the edge of the placenta is located at the edge of the cervical opening. If the edge of the low lying placenta is about 2 cm away from the opening of the cervix, but away from the edge of the cervical opening, it is known as low lying placenta.
Placenta previa risks
Why a pregnant woman develops placenta previa is largely unknown. Nonetheless, existence of certain factors could increase the risk of developing placenta previa during pregnancy. Women who smoke have a greater risk of developing this condition. Drug abuse can increase the risk of developing this condition. If placenta previa occurred in an earlier pregnancy, you might develop this condition in later pregnancies. This condition could develop in women pregnant with twins or multiple fetuses. Women who gave birth through c-section in previous pregnancies have a greater risk of developing placenta previa. History of uterine surgery such as fibroid removal could be responsible for this condition.
Dangers of placenta previa
Painless bleeding during pregnancy is a symptom of placenta previa. The bleeding usually starts from the late second trimester of pregnancy. Bed rest or pelvic rest might be advised to prevent bleeding. Pregnant women diagnosed with placenta previa should avoid strenuous physical activities. You might need hospitalization to stop severe bleeding. If the baby is matured enough to be delivered, a c-section would be required for the process. Pregnant women with placenta previa usually give birth to babies with low birth weight.