When the placenta lies low in the uterus, it may cover the cervix. That means it partly or completely blocks the opening. This is called placenta previa. It may cause vaginal bleeding. This type of bleeding often occurs without pain.
Placenta previa occurs in 1 in 200 women. It is more common in those who:
- have had more than one child
- have had a cesarean birth
- have had surgery on the uterus
- are carrying twins or triplets
Like placental abruption, bleeding from placenta previa is a serious condition that needs to be treated quickly.
There are times at which an ultrasound at 18-20 weeks, the placenta appears to be “low lying”, a “marginal placenta previa”, or a “partial placenta previa”. In the majority of cases, this resolves as the pregnancy progresses. Your doctor will be sure to note the location of your placenta on your ultrasound and let you know if a repeat look is necessary later in the pregnancy.
If your placenta completely covers the cervix for the duration of the pregnancy, especially if you have had episodes of bleeding, it will be likely that your baby will be delivered early and always by cesarean section.
The bleeding from placenta previa can be very frightening and worrisome. Some women require hospitalization prior to the decision to deliver the baby.
Make sure you let your doctor know if you have bleeding, at any time, but especially in the second and third trimester.
