Placenta previa, otherwise called a low-lying placenta, is when the placenta covers a part or the entire cervix during the third trimester of pregnancy. Read about its types, symptoms, causes, complications, and precautions to be taken.
The placenta is a special organ that develops in the uterus only during pregnancy. It provides nutrition and oxygen to the growing fetus and assists with the elimination of waste products via the umbilical cord connection. The baby is connected to the placenta through the umbilical cord. It is usually located near the top portion of the uterus. As pregnancy advances and the uterus stretches and grows, the placenta moves also.
The placenta is usually located low in the uterus during early pregnancy. But as the pregnancy progresses and by the third trimester, the placenta should be ideally near the top of the uterus. This allows the baby to be delivered through the cervix without anything blocking the path.
If there is placenta previa, it means the placenta is lying lower in the uterus, probably blocking the passage of the baby's arrival (cervix). This abnormal position of the placenta can result in severe bleeding throughout the pregnancy and delivery. Women with this condition must avoid strenuous activities, such as sex, douching, using tampons, running, and jumping. If the condition does not resolve, the baby might have to be delivered through a C-section.
A placenta previa can either cover the cervix partially or totally. So, depending on that, we have two types:
Partial placenta previa (minor) - Only part of the cervical opening is covered by the placenta.
Low-lying placenta previa - The placenta is positioned at the edge of the cervix and does not cover the opening.
Complete placenta previa (major) - The entire cervical opening is covered by the placenta.
Marginal placenta previa - In this case, the placenta lies in the lower segment of the uterus and presses the cervix. The edge of the placenta is within 2 cm of the cervix and not covering the opening.
Bright red, painless vaginal bleeding in the second or third trimester is a sign to suspect placenta previa. The other symptoms include sharp cramps, abdominal pain, and bleeding after sex. In a majority of women detected with placenta previa during early pregnancy, the placenta migrates upwards (due to the growth of the uterus), and the condition resolves independently. The doctor may order a scan to recheck the location after a few weeks.
But, in those whom it is still detected at later stages or still persists in the third trimester, it is less likely to migrate upwards any longer. Then, the delivery will be required to be done via a cesarean section.
Whereas, in minor (partial) cases, vaginal delivery may be attempted if deemed suitable by the attending doctor. Irrespective of a major or minor one, some precautions are called for during this pregnancy.
If you have painless, bright red bleeding or spotting during the course of your pregnancy, it is critical to be at the hospital at the earliest. In case of severe bleeding, it can be life-threatening, and you may require blood transfusions. Also, consult the doctor for any other specific restrictions that may be applicable to you.
The possible causes include:
Uterine scarring during previous cesarean section delivery, D and C procedures, or any other surgery involving the uterus.
When the functional capacity of the placenta is lowered due to multiple gestations, smoking mother, or living in a high altitude, the placenta grows larger to compensate for lost functions, and this causes placenta previa.
The following factors increase the risk of having placenta previa:
Breech (baby’s buttock is positioned to be delivered first) or transverse positioned baby (baby lies horizontally across the womb).
The uterus is shaped abnormally.
History of a miscarriage.
Advanced maternal age.
Other uterine surgeries, which include cesarean delivery and dilation and curettage (D&C).
Abnormally large placenta.
Previous history of placenta previa.
This condition is usually diagnosed during a routine ultrasound at 20 weeks. But it is nothing to worry about, as the placenta, in the majority of cases, is positioned lower during early pregnancy. As the weeks go by, the placenta generally corrects itself. Only around 10 % of cases will lead to major placenta previa (according to the Royal College of Obstetricians and Gynecologists).
If you notice painless bleeding during the second half of your pregnancy, consult a doctor, who will detect the position of the placenta using the following methods:
Transvaginal ultrasound - A transducer is placed inside the vagina, which provides images of the inside of the uterus and cervix. This diagnosis placenta previa most accurately.
MRI (magnetic resonance imaging) - This gives detailed images of the placenta’s location.
Depending on how much bleeding is occurring, the baby’s health, the position of the baby and placenta, and how far along you are, the doctor will form a treatment plan. The doctor usually monitors the amount of bleeding before treating the condition.
No to Minimal Vaginal Bleeding:
Bed rest as much as possible.
Standing and sitting only when absolutely necessary.
Abstinence from sex.
Avoid traveling and bumpy roads.
No vaginal examination.
No vigorous exercises or jumping.
If you still bleed, then consult your doctor as soon as possible.
Considerable Amount of Vaginal Bleeding:
This requires hospitalization and bed rest.
You might need blood transfusion if you have lost a lot of blood.
Medicines will be prescribed for premature labor.
Severe Vaginal Bleeding:
If you have severe vaginal bleeding, then the doctor will schedule a C-section as early as possible. It is usually done after 36 weeks. In case the C-section has to be done earlier, then the doctor injects corticosteroid injections to help the baby’s lungs mature fast.
Uncontrollable Vaginal Bleeding:
An emergency cesarean delivery is done.
What Are the Complications of Placenta Previa?
For mother: Bleeding during labor and after delivery.
For baby: Growth restriction, premature birth, and death.
To know more about the possible complications and treatment options of placenta previa, consult an obstetrician and gynecologist online.
In placenta previa, the placenta of the fetus hides the cervix portion of the mother. The cervix being the outlet of the delivery, there might be some complications. Severe bleeding and pain might be seen during the delivery of the baby.
Most of this condition is diagnosed during a regular pregnancy check-up. This happens in the second trimester of pregnancy. The technique used to detect this condition is ultrasound imaging. Placenta previa is also identified in cases of vaginal bleeding.
Placenta previa is a condition where the cervix of the mother gets blocked by the baby’s placenta. This might be harmful to the baby during delivery. So it is advised that the mother should take rest during such conditions. This will make them feel more comfortable and relaxed, so they become mentally and physically ready.
In placenta previa, bleeding happens during the third trimester of pregnancy. The labor period is the triggering factor for bleeding. This happens due to the thinning of the lower part of the uterus during the third trimester. You consult your doctor and get proper guidance.
Complete recovery from the condition placenta previa is not possible. But you can cope up with the condition. The following can help you cope up with placenta previa.
Education and knowledge about placenta previa are important.
The pregnant mother should take a lot of rest. The mother should make their mind ready for both C-section and normal delivery. Even though normal delivery is rare, the mother should hope for the best.
Get adequate rest.
The common symptom of placenta previa is vaginal bleeding. This might not be accompanied by pain most of the time. But in some patients, due to the contractions in the uterus, abdominal pain might be present. If it is the first delivery of the mother, then placenta previa can cause a certain degree of anxiousness.
Having delivered a baby by placenta previa does not necessarily mean your baby will be sick. But some babies are known to be born by premature birth, low weight, breathing problems, and cerebral palsy. You should consult your doctor regarding the health of the mother and the baby.
There are no exact ways to prevent placenta previa. But you can try to avoid the factors that serve as a cause of placenta previa. Avoid the following to reduce the possibilities of placenta previa.
- Smoking during pregnancy.
- Multiple pregnancies.
- Living in regions with high altitude.
Almost all the cases of placenta previa is a C-section delivery. Since it is pre-planned, the surgery is scheduled somewhere around 37 weeks to 38 weeks. The surgery date might vary depending on the intensity of the vaginal bleeding.
If you are having placenta previa, bleeding can be controlled by making a few lifestyle changes. This can prevent the condition from becoming worse.
- Do not climb the stairs up and down.
- Do not sit on the sofa and bed. Always prefer sitting on the floor. Sitting in a butterfly position can improve the health of pregnant women and babies.
If there is continuous bleeding, even after making these changes, you should report to the doctor immediately.
Last reviewed at:
29 Aug 2022 - 5 min read
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