Placenta previa occurs when the placenta lies unusually low in the uterus, close to your cervix. The placenta is what supplies oxygen and nutrients to your baby, and should normally be located near the top of the uterus. Placenta previa that occurs in the early stages of pregnancy isn’t usually regarded as a major issue.

If the placenta is still low during the latter parts of pregnancy, however, this can lead to vaginal bleeding, the need for a cesarean section and/or preterm birth. The placenta doesn’t move throughout a pregnancy, but it can certainly be located further from the cervix as your pregnancy progresses and your uterus expands. Placenta previa is present in 1 in every 200 deliveries.

Women who are at risk of developing placenta previa have often had previous c-sections, have had some type of uterine surgery, are carrying multiples, smoking cigarettes or using cocaine.