Placenta Previa

What is Placenta Previa?

Placenta previa is a condition where the placenta partially or completely blocks the cervix of pregnant women during the last months of pregnancy. The placenta is an organ that develops in the uterus during pregnancy, supplying oxygen and nutrients to the fetus through the umbilical cord.

Types of Placenta Previa

There are three types of placenta previa – marginal, partial and complete or total. Marginal placenta previa is when the placenta is placed at the edge of the cervix, touching but not covering it. Partial placenta previa is when the placenta partially covers the cervix, while complete or total placenta previa is when the placenta completely covers the cervix, blocking the baby’s exit from the vagina. All types of placenta previa can cause vaginal bleeding during pregnancy and labor, which is why most women need a C-section delivery.

Prevalence

Placenta previa occurs in approximately 1 in 200 pregnancies, and healthcare providers usually diagnose it during the second trimester through an ultrasound.

Placenta Previa vs. Placental Abruption

Unlike placental abruption, where the placenta detaches from the uterus, the placenta stays attached to the uterus in placenta previa, despite its complicated positioning. However, both conditions can cause vaginal bleeding during pregnancy and labor.

Is placenta previa the same as anterior placenta?

Placenta previa isn’t the same as anterior placenta. Your placenta can grow anywhere in your uterus. An anterior placement of the placenta means the placenta has implanted in the front of your body. Think of anterior placenta as a pillow between your baby and your stomach.

Symptoms of placenta previa

What are the symptoms of placenta previa?

The most common symptoms of placenta previa are:

• Bright red bleeding from your vagina. The bleeding often starts near the second half of pregnancy. It can also start, stop, then start again a few days later.
• Mild cramping or contractions in your abdomen, belly or back.
• The amount of vaginal bleeding can vary and is often not accompanied by any pain.

What causes placenta previa?

There isn’t a known cause of placenta previa. There are some factors that can increase your risk of developing placenta previa, including your medical history and certain lifestyle habits.

Risk factors for developing placenta previa

There are several factors that increase your risk for placenta previa during pregnancy:

• You smoke cigarettes or use cocaine.
• You’re 35 or older.
• You’ve been pregnant several times before.
• You’re pregnant with twins, triplets or more.
• You’ve had surgery on your uterus, including a C-section or a D&C (dilation and curettage).
• You have a history of uterine fibroids.

Possible Complications of Placenta Previa

For You:

If you have placenta previa, there are risks for both you and your baby. Complications from placenta previa include:

• Bleeding: Severe bleeding can occur during pregnancy, labor or delivery.
• Early birth: If you’re bleeding severely, your healthcare provider may perform an emergency C-section before your baby is full term (40 weeks).
• Blood loss: Anemia, low blood pressure, pale skin or shortness of breath are all side effects of losing too much blood.
• Placenta accreta: The placenta grows too deeply in the wall of your uterus. This can cause severe bleeding after delivery.
• Placental abruption: The placenta separates from your uterus before your baby is born. This decreases your baby’s supply of oxygen and nutrients.

For Baby:

• Premature birth: If your bleeding is severe and you need an emergency C-section, your baby may be born too early.
• Low birth weight: Trouble staying warm and poor weight gain are potential side effects of low birth weight.
• Respiratory issues: Underdeveloped lungs could make breathing more difficult.

Can You Have Placenta Previa Without Bleeding?

Yes, it’s possible to have placenta previa and not experience vaginal bleeding. You could have mild cramping or pain in your pelvic region or back. It’s best to discuss any bleeding or pelvic pain you have with your healthcare provider.

Why Do You Bleed When You Have Placenta Previa?

There are two main reasons you bleed if you have placenta previa. They have to do with how your body prepares for labor.

Understanding the Role of the Cervix

Your cervix plays a critical role in pregnancy and birth. It’s the opening from your uterus to your vagina, and it undergoes changes as your pregnancy progresses. In the third trimester, your cervix thins and spreads to prepare for birth. However, if your placenta is touching or covering your cervix, this process can cause bleeding.

The Role of Placenta Previa in Miscarriage

While miscarriage is a common pregnancy complication, placenta previa is not typically the cause. Pregnancy care providers typically diagnose placenta previa around or after the 20th week of pregnancy.

Diagnosing Placenta Previa

Pregnancy care providers usually identify placenta previa during a routine ultrasound around 20 weeks of pregnancy. If a person experiences symptoms like vaginal bleeding, placenta previa may also be detected. Healthcare providers use vaginal and abdominal ultrasounds to diagnose placenta previa and monitor the placement of the placenta throughout the pregnancy. From there, they can determine the appropriate treatment.

Management and Treatment

When dealing with placenta previa, the goal is to ensure that delivery occurs as close to the due date as possible. The safest way is often through a C-section if bleeding continues. However, the treatment of placenta previa largely depends on several factors:

• The severity of the bleeding
• The gestational age of the baby
• The position of the placenta and the baby
• The health of both the mother and the baby

If the condition is detected early in the second trimester, it may resolve on its own as the uterus expands; however, the chances of the placenta moving upwards decrease the later it’s detected.

Does Placenta Previa Go Away?

There’s a good chance that placenta previa can resolve on its own if it is discovered early in the pregnancy. The placenta can move upwards as the uterus keeps expanding in the third trimester. But if it remains covering the cervix late in the pregnancy, the chances of it resolving on its own decrease dramatically. Your healthcare provider will keep an eye on the placenta’s position to determine if it has moved before delivery.

Treatment Options

If your placenta covers part of the cervix, and you aren’t bleeding, your healthcare provider may suggest:

• Reducing physical activity
• Resting frequently
• No sexual intercourse, tampons, or douching
• More prenatal appointments and ultrasounds

For moderate to severe cases or frequent bleeding, treatment options may include:

• Hospitalization for bed rest
• Medicines to prevent early labor
• Steroid shots for the baby’s lung development
• Blood transfusions for heavy bleeding
• Emergency C-section for uncontrolled and heavy bleeding

Prevention

While there is no way to prevent placenta previa, there are certain risk factors that can be managed, such as abstaining from smoking and cocaine use. Once diagnosed, there are steps that can be taken to reduce vaginal bleeding.

Outlook/Prognosis

Individualized treatment is necessary for placenta previa. This includes frequent monitoring during the second and third trimesters, modified physical activities, and blood tests after delivery to check blood counts. Early delivery may be recommended, depending on factors such as gestational age, placental position, and amount of bleeding.

Delivery Options

If the placenta is marginal, a vaginal delivery may be possible. However, if there is a risk of bleeding, a C-section may be necessary. In cases where the placenta partially or completely covers the cervix, a C-section is usually the safest option. In some cases, an emergency C-section may be required if bleeding becomes severe.

Can placenta previa cause birth defects?

It’s uncommon for placenta previa to cause birth defects. Your baby may be born premature if your healthcare provider feels it’s the safest time to deliver. Premature birth carries some complications such as low birth weight and respiratory problems.

Will I get placenta previa again?

If you’ve had placenta previa in a past pregnancy, your chances of having it again are around 2%. If you become pregnant, let your healthcare provider know so that they’re aware of your medical history.

Will placenta previa affect my fertility?

Placenta previa doesn’t impact your chances of getting pregnant again. You’ll have a small risk of getting placenta previa again if you become pregnant.

What questions should I ask my doctor?

Your healthcare provider should be able to answer your questions and prepare you for treatment of placenta previa. Here are some questions you might ask:

• Is the baby’s life in danger? Is mine?
• What are my treatment options?
• How will I know if my placenta previa goes away?
• Should I limit certain activities?
• Can the baby be born now?
• What are potential complications?
• Will I need additional ultrasounds or tests?
• What are the signs that I need to go to the hospital?
• What questions will my doctor ask me?
• When did you first notice bleeding?
• How heavy is the bleeding?
• Is bleeding constant or does it come and go?
• Do you have any pelvic pain?
• Have you had pregnancy complications before?
• Have you had uterine surgeries?
• Do you smoke or use cocaine?
• Is there someone to care for you if bed rest is required?