As you may be aware, the placenta is the organ that nourishes the growing fetus. During the first trimester, the placenta is low lying but as pregnancy progresses the placenta moves towards the upper side of the uterus, keeping the cervix open to enable delivery.
But after the third trimester if the placenta still lies at the lower portion of the uterus partially or fully covering the cervix, it is a cause for concern and is called placenta previa.
There may not be any properly defined causes for placenta previa but they are more prominently found in women who have an abnormal shape of the uterus by heredity, those who have fibroids or have undergone surgery for fibroids, multiple pregnancy and those having an history of placenta previa.
It may also occur in women who have a scarred uterine wall caused by C-section, abortions or previous pregnancies. It may also be common in women who smoke and have their first pregnancy after the age of 35.
Placenta previa is normally diagnosed after the second trimester or in the early third trimester. This is because at this time the lower portion of the uterus is formed which causes the placenta to move upwards.
But if it does not, it will result in painless heavy vaginal bleeding which may occur repeatedly. So if you experience any of these symptoms it is very important to consult your practitioner. It is not wise to go for labor in most conditions but your health care provider knows best. So keep her informed.
Placenta previa is basically of four types, complete placenta previa which covers the cervix completely. This is very serious and may cause very heavy bleeding leading to death. Partial placenta previa covers half the cervix but still has high risk of bleeding so the patient will mostly have a C-section.
Marginal placenta previa is when the placenta is at the margin of the cervix. A normal labor is possible but still has a high risk of bleeding attached to it. The lateral placenta position is when the placenta is located very near the cervix. A normal delivery is possible but this also has a high risk of bleeding though lesser than other types.