The placenta is an organ that develops in the uterus during pregnancy. Its
purpose is to nourish the baby. Oxygen and nutrients pass through the placenta
to the baby, and waste products pass back out.
Placenta Previa occurs when the placenta becomes implanted near or over
the cervix. The cervix is the lower part of the uterus that opens into the
vagina. With this condition, the placenta may cover part or all of the opening
to the vagina. Anything that disrupts the placenta, such as sexual intercourse
or digital exam of the vagina and cervix, may cause bleeding.
Placenta Previa can cause problems in pregnancy and birth. These include:
- Abnormal bleeding, sometimes heavy
- Premature separation of the placenta from the uterus
- Premature birth
- Emergency cesarean delivery
Risk Factors
A risk factor is something that increases your chance of getting a disease or
condition. Risk factors include:
- Previous cesarean section
- Uterine problems, such as fibroids
- Multiple pregnancy (two or more fetuses)
- Multiple previous full-term pregnancies
- Increasing age
- Smoking
Symptoms
Placenta Previa varies in severity depending on how much of the cervix is covered. The main symptom is painless bleeding from the vagina. This bleeding can range from light to very heavy. It usually occurs suddenly during late pregnancy. Spotting earlier in pregnancy may indicate Placenta Previa but in most cases the placenta safely grows away from the cervical opening by the time of delivery.
Diagnosis
The doctor will ask about your symptoms and medical history, and perform a physical exam. He or she will not, however, perform a pelvic exam if Placenta Previa is a possibility. A pelvic exam may cause bleeding. Instead, an ultrasound will be done through the vagina or abdomen to view the placenta in the uterus. If Placenta Previa is detected early in pregnancy, with or without bleeding, another ultrasound will be done during the third trimester to be sure it has resolved.
Treatment
Treatment depends on several factors, including the amount of bleeding.
If placenta previa is diagnosed through an ultrasound but you have no
bleeding, you do not need any treatment besides having the condition checked
regularly. Your doctor may suggest that you take extra iron and folate in case
you do have bleeding.
If only minor bleeding occurs and your pregnancy is 36 weeks or less, you
may need to go on bed rest. If the bleeding stops, you may be allowed to get out
of bed. However, you still need to be careful due to the risk of sudden
bleeding. You should avoid intercourse and orgasm because they may start
contractions and cause trauma to your cervix.
If the bleeding is heavy or your pregnancy is 37 weeks or more, the baby
is delivered. You will most likely need a cesarean section. However, a vaginal
delivery may be possible under rare circumstances, such as:
- Your placenta is only partly blocking the cervical opening and you do not
have much bleeding
- Labor has progressed to the point where the baby can be delivered faster
vaginally than by cesarean section
Prevention
There are no guidelines for preventing
Placenta Previa. However, if
you have it, you need to do the following to prevent bleeding:
- Have the condition checked regularly
- Carefully follow any instructions you are given regarding bed rest and
what to do if you have bleeding or contractions