Placenta Previa
Thankfully, placenta previa is a very uncommon pregnancy complication. Placenta previa can cause excessive bleeding before or during delivery. The placenta forms soon after conception and provides the necessary oxygen and nutrients your baby needs to grow and develop, plus it removes the waste from your baby’s blood. After the placenta has formed, it attaches itself to the wall of the uterus. The umbilical cord rises from it, forming an important connection between mother and baby.
In a normal pregnancy, the placenta attaches itself to the wall of the uterus, but away from the cervix opening. Placenta previa occurs when the placenta attaches itself to the lower part of the uterine wall and either partially or completely covers the cervix.
When the cervix starts to open in preparation for labor, the placenta is detached, which usually triggers severe vaginal bleeding. The good thing is that unlike other complications, placenta previa is almost always detected before a woman or her baby is in any kind of danger.
Placenta Previa Symptoms
The biggest sign that placenta previa has taken place is a bright red, yet painless bleeding from the vagina during the 2nd or 3rd trimesters of pregnancy. Some women experience light bleeding or spotting during their 1st and beginning of their 2nd trimester. This isn’t placenta previa though. Placenta previa happens towards the end of the 2nd trimester or at anytime during the 3rd trimester.
The amount of bleeding can range from mild to severe, and usually stops, but almost always returns within days or weeks. Some women experience contractions with their placenta previa.
Types of Placenta Previa
There are three specific types of placenta previa; total placenta previa, partial placenta previa and marginal placenta previa. In total placenta previa, the placenta completely covers the cervix, while partial placenta previa covers part of the cervix, and the marginal placenta previa is when the placenta has approached the edge of the cervix.
A low-lying placenta is a term used to reference a placenta that lies low in the uterus but doesn’t come close enough to the cervix for it to be considered a marginal placenta previa. Unlike the other types of placenta previa, a low-lying placenta causes bleeding after delivery and doesn’t usually cause signs or symptoms during the pregnancy.
Causes of Placenta Previa
Some of the things that can cause placenta previa include:
- Abnormally shaped uterus
- A large placenta (usually occurs in a multiple pregnancy)
- Endometrium (scars in the lining of the uterus)
- Women who have previously given birth
- Women who had a previous c-section
- Over the age of 35
- Smoking
- Placenta previa occurred in previous pregnancy
- Previous uterine surgery
Complications of Placenta Previa
There are many complications that can occur with placenta previa. The biggest concern is the bleeding, which can lead to hemorrhaging during labor and delivery, maternal shock or even death. Premature births are also caused by severe bleeding, which c-sections are performed with urgency. Placenta accreta can also occur. Placenta accreta happens when the placenta attaches too deeply and firmly into the uterine wall, making it difficult for the placenta to detach after delivery. This complication is very serious and almost always leads to a hysterectomy (removal of uterus).
