Placenta Previa

What is placenta previa?

Placenta previa is a condition in pregnancy in which the placenta lies below the baby in the uterus. It may partially or completely cover the opening of the uterus (cervix). This happens in less than 1% of pregnancies.

The placenta develops in the uterus during pregnancy and allows oxygen, nourishment, and wastes to pass between the mother and the baby.

Often, as the uterus grows during the first 3 months of pregnancy, a low-lying placenta moves away from the opening of the uterus. If the placenta does not move up and out of the way, it is called previa. If the placenta is previa, the baby may need to be delivered early by cesarean section (C-section).

How does it occur?

Placenta previa occurs when the fertilized egg attaches to the lower part of the uterus instead of the top or sides of the uterus.

Some women are at higher risk for this condition than others. The risk for placenta previa is greater for women who:

• are older than 35
• have had more than one previous delivery
• have had many abortions
• are carrying twins
• have had a C-section
• have had placenta previa before.

What are the symptoms?

The first sign of placenta previa is bright red bleeding or spotting. Sometimes this bleeding can be confused with a type of light bleeding that often occurs during normal labor, called the bloody show. There is usually no pain, tenderness, uterine contractions, or cramps, although these symptoms may occur.

In some cases, placenta previa may cause the baby to grow more slowly. This is called intrauterine growth retardation (IUGR).

How is it diagnosed?

Tests that may be done are:

• ultrasound scan to see where the placenta is attached in the uterus
• blood tests
• double setup exam if there is no time for an ultrasound or ultrasound is not available (A double setup exam is an exam of the cervix with a speculum in the operating room. Your doctor will be ready to do a C-section if necessary.).

How is it treated?

Treatment depends on how much bleeding you have had and how far along you are in the pregnancy. The results of blood tests will help to determine if you need a blood transfusion. The decision to deliver the baby will depend on how far along the pregnancy is and how heavy the bleeding is. If you have severe bleeding, the baby is usually delivered by C-section as soon as possible to save your life and the baby.

If you have bleeding and it is before 37 weeks in the pregnancy, your healthcare provider may recommend:

• bed rest
• staying in the hospital
• ultrasound tests every 1 to 4 weeks if the bleeding stops
• nonstress tests or biophysical profiles to make sure the baby is doing well
• iron pills or a blood transfusion if your blood count is too low.

If you have 2 or 3 bleeding episodes before 37 weeks, your provider may recommend:

• bed rest or staying in the hospital
• a drug to stop contractions if the bleeding is caused by contractions of the uterus
• amniocentesis to see if the baby's lungs are mature enough for delivery.

If the bleeding occurs after 37 weeks of pregnancy and the placenta does not completely cover the opening to the uterus, your provider may allow you to go into labor and try a vaginal delivery. You will be monitored closely. At the first sign of increased bleeding you may need a C-section to deliver the baby.

If the placenta does completely cover the opening of the uterus, a C-section is the only way to deliver the baby safely.

How can I take care of myself?

• To prevent bleeding when you have placenta previa, limit your regular activity or rest in bed.
• Do not put anything into your vagina, such as a tampon, because it may cause more bleeding.
• Do not have sexual intercourse.
• If your healthcare provider prescribes iron, be sure you take it. It is best to take iron after meals so it will not upset your stomach.
• Avoid a lot of bending and lifting.
• Tell your provider if you have any pain, contractions, or bleeding.

What can be done to help prevent placenta previa?

There is nothing you can do to prevent placenta previa. To help prevent complications of a previa, follow your healthcare provider's instructions.