Placenta Previa

During pregnancy, the cervix sits high in the vagina. Its texture changes from firm to very soft. Because pregnancy causes increased blood flow to the cervix, some people experience implantation bleeding about one to two weeks after conception.

The Cervix in Early Pregnancy

The cervix is the narrow end of the uterus that connects to the vagina. The cervix changes throughout the menstrual cycle and during pregnancy. Its location and texture also change as the body goes through hormonal shifts.

The cervix sits higher near the uterus during pregnancy and lower during menstruation. It usually feels firm, like unripened fruit, but softens during pregnancy.

During pregnancy, your healthcare provider will perform an exam to check your cervix. Some people may have questions about checking their cervix at home.

This article provides an overview of cervical changes, how to monitor them, and when to see a healthcare provider.

Photo composite by Michela Buttignol for Verywell Health; Getty Images

Menstruation and the Cervix Before Pregnancy

The cervix changes throughout the month based on your hormone levels and menstrual phase. It is a circular band of muscle that can change its shape, texture, and position.

Position and Texture

The menstrual cycle begins with your period (menstruation). During menstruation, the cervix sits lower in the vagina. It dilates (widens) to allow the passing of the inner lining of the uterus through the vagina (vaginal bleeding).

Ovulation occurs in the middle of the menstrual cycle, when the ovaries release a mature egg. During ovulation, the cervix rises to a higher level in the vagina. The texture of the cervix is usually firm and may feel like unripened fruit.

After a Missed Period

The cervix sits higher in the vagina during ovulation. If the mature egg released by the ovaries is fertilized by sperm, pregnancy may occur. Once your body conceives, the cervix remains higher in the vagina. Usually, it moves lower in the vagina during your period. When you miss your period, it remains high.

Cervix in Early Pregnancy

In early pregnancy, the cervix remains high in the vagina and starts to change in texture. The cervix plays an important role during pregnancy.

Position and Texture

During pregnancy, the cervix sits high in the vagina. Its texture changes from firm to very soft. Because pregnancy causes increased blood flow to the cervix, some people experience implantation bleeding about one to two weeks after conception.

Discharge

It is common to experience a change in cervical discharge during pregnancy and throughout the menstrual cycle. Some people use it to determine when they are most fertile.

During ovulation, the cervical mucus feels stretchy like egg whites. Usually, after menstruation, cervical discharge thickens and dries up. During pregnancy, most people experience an increase in the amount of discharge. It may also become thicker.

Importance

A healthy cervix is essential for a healthy pregnancy. Its purpose during pregnancy is to keep the fetus in the uterus until it is full-term. At conception, the cervix creates thick, sticky mucus that forms the mucus plug. This plug protects the fetus from infection during pregnancy.

Throughout the Trimesters

Before pregnancy, the cervix is long and firm in texture. During pregnancy, the cervix softens and starts to become shorter. When it is time for birth, the cervix continues to shorten and dilates to make room for the fetus to fit through the birth canal.

How to Feel for the Cervix Using Fingers

During pregnancy, your healthcare provider will check your cervix using gloved fingers to determine if it is dilated and how soon labor could begin. You may have questions about checking your cervix at home. Checking your cervix can be challenging. It is difficult to know what you are feeling, and healthcare providers have years of experience locating and assessing the cervix.

Before pregnancy, the cervix will feel tight and firm. Once you are pregnant, it will feel soft. Healthcare providers recommend setting up a prenatal appointment as soon as you suspect that you are pregnant. It is safer for you and your baby to have your cervical checks performed by your provider. Research shows that the more cervical checks a pregnant person has, the higher the risk for infection.

A cervical check may provide a clue as to whether or not you are pregnant, but the only way to know for sure is to take a pregnancy test.

Cervical Complications in Early Pregnancy

The cervix provides an important barrier during pregnancy. It protects against infection reaching the uterus and fetus and keeps the baby in the uterus until full term.

Complications of the cervix can cause serious problems for both a pregnant person and their baby. Having a low cervix in pregnancy can lead to premature labor and birth. Possible cervical complications in early pregnancy include:

• Infection: When there is an infection in the vagina, cervix, or uterus, the cervical discharge may be green, blood-tinged, and foul-smelling.
• Short cervix: A short cervix (less than 2.5 centimeters long at 20 weeks of pregnancy) means it is shorter than it should be. Your healthcare provider can determine if you have a short cervix. This increases the risk of premature labor and birth.
• Cervical insufficiency: When the cervix begins to dilate too early in pregnancy, it may lead to premature birth or miscarriage.
• Placenta previa: This occurs when the placenta that provides the fetus with nutrients covers part of the cervix, which can lead to serious pregnancy complications and usually requires a surgical, cesarean delivery (C-section).

A short cervix raises the risk of premature labor and birth. People with a short cervix may experience early effacement. Effacement is the process of the cervix becoming thinner and preparing for birth.

Follow-Ups to Monitor Cervical Changes

Throughout your pregnancy, your healthcare provider will monitor your cervix. Your provider can use a vaginal ultrasound or a pelvic exam to examine the cervix and diagnose any problems.

Diagnostic tests to evaluate the cervix include:

• Pelvic exam: The provider inserts gloved fingers into the vaginal canal to feel the cervix for signs of thinning or dilation.
• Ultrasound: The provider uses a vaginal ultrasound to measure the cervix.
• Pap test: The provider scrapes cells from the cervix and sends them to the lab to test for signs of cancer.

Pregnant people with cervical insufficiency may benefit from a procedure called cervical cerclage. During this procedure, a healthcare provider reinforces the cervix by placing a stitch to keep it closed. This helps to prevent the cervix from dilating too early in pregnancy. Talk with your healthcare provider if you are concerned about or have a history of premature labor or birth.

Summary

The cervix connects the bottom of the uterus to the top of the vagina. It goes through several changes throughout the menstrual cycle and during pregnancy. During menstruation, the cervix sits lower in the vagina. During ovulation and pregnancy, it rises higher in the vagina. The cervix feels firm to the touch and softens throughout pregnancy.

The cervix provides a barrier for the fetus and protects against infection. It also helps the fetus stay in the uterus until they are full-term. Your healthcare provider may check your cervix during a pelvic exam or with a vaginal ultrasound.

18 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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Placenta Previa

Placenta previa is a condition during pregnancy where the placenta blocks all or part of your baby’s exit from your vagina. The most common symptom is vaginal bleeding in the second half of pregnancy. People with placenta previa typically need a C-section delivery.

Overview

With placenta previa, the placenta covers all or part of the cervix.

What is placenta previa?

Placenta previa is a condition when the placenta blocks all or part of your cervix in the last months of pregnancy. The placenta develops in your uterus during pregnancy. It’s a sac-like organ that supplies oxygen and nutrients to the fetus through the umbilical cord.

The placenta stretches and grows through pregnancy. It’s common for it to be low in your uterus in early pregnancy. In the third trimester (weeks 28 to 40 of pregnancy), the placenta should move to the top of your uterus. This happens so your baby has a clear path to the vagina for delivery. Placenta previa occurs when the placenta doesn’t move to the top of your uterus. This means the placenta is blocking your baby’s exit from your vagina.

What are the types of placenta previa?

There are several types of placenta previa:

• Marginal placenta previa: The placenta is positioned at the edge of your cervix. It’s touching your cervix, but not covering it. This type of placenta previa is more likely to resolve on its own before your baby’s due date.
• Partial placenta previa: The placenta partially covers your cervix.
• Complete or total placenta previa: The placenta is completely covering your cervix, blocking your vagina. This type of placenta previa is less likely to correct itself.

Each type of placenta previa can cause vaginal bleeding during pregnancy and labor. Due to the high risk of bleeding, most people will require a Caesarean (C-section) delivery.

How common is placenta previa?

Placenta previa occurs in about 1 in 200 pregnancies. Pregnancy care providers usually diagnose it in the second trimester during an ultrasound.

What is the difference between placenta previa and placental abruption?

In placenta previa, the placenta is covering all or part of your cervix. Even though the placenta is in a complicated position, it’s still attached to your uterus. A placental abruption is when the placenta detaches from your uterus. 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 and Causes

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.

What are the 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.

What are possible complications of placenta previa?

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.

• 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.

• Your cervix is the opening from uterus to your vagina. As pregnancy progresses in the third trimester, your cervix thins (effaces) and spreads to prepare for birth. If your placenta is touching or covering your cervix, this thinning will cause you to bleed.
• During labor, your cervix opens (dilates) in order to allow the baby to exit your uterus and descend down your vagina. When your cervix opens, the blood vessels connecting the placenta to your uterus are torn and can cause bleeding.

Can placenta previa cause a miscarriage?

Miscarriage occurs when you experience a loss of pregnancy before 20 weeks. Pregnancy care providers don’t typically diagnose placenta previa until around or after the 20th week of pregnancy. It’s uncommon that placenta previa would be the cause of a miscarriage.

Diagnosis and Tests

How is placenta previa diagnosed?

Pregnancy care providers usually identify placenta previa in a routine ultrasound around 20 weeks of pregnancy. It’s sometimes found when a person experiences symptoms of placenta previa like vaginal bleeding. Your provider will recommend ultrasounds to monitor the placement of the placenta for the remainder of your pregnancy.

What tests are used to diagnose placenta previa?

Your healthcare provider will diagnose placenta previa using ultrasounds that show the inside of the female reproductive system:

• Vaginal ultrasound (or transvaginal ultrasound): Your provider places a wand-like device (a transducer) into your vagina to check the position of your baby, the placenta and your cervix.
• Abdominal ultrasound: Your provider places gel on your abdomen, then moves a handheld device (the transducer) around the outside of your belly. This can also show the position of your baby, the placenta and your cervix.

Both types of ultrasound show the images on a monitor or screen. Your pregnancy care provider will determine how much of your cervix is covered by the placenta and recommend treatment.

Management and Treatment

How is placenta previa treated?

The goal is to get you as close to your due date as possible. Delivering via C-section is often the safest treatment if bleeding continues. Treatment of placenta previa depends on:

• How severely you’re bleeding.
• The gestational age of your baby.
• The position of the placenta and your baby.
• The health of you and your baby.

If your provider finds placenta previa early in your second trimester, it can get better on its own. The position of the placenta can change as your uterus expands to accommodate the growing baby. There is often less of a chance that the placenta will move higher in your uterus if your provider diagnoses you with the condition later in pregnancy.

If the placenta is near or covering just part of the cervix and you’re not bleeding, your healthcare provider may recommend:

• Reducing strenuous activities like running, lifting and exercising.
• Bed rest at home.
• No sexual intercourse, tampons or douching.
• More frequent prenatal appointments and ultrasounds.

For moderate to severe cases of placenta previa or frequent bleeding, other treatments could include:

• Bed rest in the hospital.
• Medicine to prevent early labor.
• Steroid shots to help the baby’s lungs develop faster.
• Blood transfusions if you experience heavy bleeding.
• An emergency C-section for heavy, uncontrolled bleeding.

Does placenta previa go away?

Placenta previa can go away on its own if it’s found in the second trimester. Going away on its own means the placenta shifts upwards to the top of your uterus. As your uterus expands in the third trimester, the placenta may still move. The later in the pregnancy it remains covering the cervix, the less likely it is to go away. Your healthcare provider will monitor the position of the placenta to see if the condition has resolved before delivery.

Prevention

Can I reduce my risk for placenta previa?

There is nothing you can do to prevent placenta previa and no surgical or medical procedure can correct it. There are certain risk factors for placenta previa that are within your control, like not smoking or using cocaine. Once your provider diagnoses the condition, there are ways to reduce the amount of vaginal bleeding.

Outlook / Prognosis

What can I expect if I have placenta previa?

Your treatment will be unique to your condition. Most people can expect:

• Frequent monitoring through the second and third trimester. Your provider does this to check the position of the placenta and watch for any changes in symptoms.
• Modified or restricted physical activities like exercise and sex.
• Blood tests post-delivery to check your blood counts.

Will my baby be born early if I have placenta previa?

Maybe. Your healthcare provider will consider the amount of bleeding, the position of the placenta and the baby’s gestational age before deciding if an early delivery is necessary. Around 36 weeks of pregnancy, the best option for the health of you and your baby could be an early delivery. Other times a person reaches full term or 40 weeks of pregnancy.

Can I still have a vaginal delivery with placenta previa?

If you have a marginal placenta previa (the placenta is close to your cervix, but not covering it), your healthcare provider may be able to deliver your baby vaginally. This carries a risk of bleeding and may be too dangerous. Your provider will discuss the safest way to deliver your baby.

Will I need a C-section if I’m diagnosed with placenta previa?

A C-section is usually the safest delivery option if you have placenta previa. If the placenta covers even a part of your cervix, a vaginal delivery can cause severe bleeding. Your provider will typically schedule your C-section in advance, but if your bleeding is too severe at any time, you may need an emergency C-section.

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?

Living With

When should I see my healthcare provider?

Call your healthcare provider immediately if you’re bleeding, cramping or experiencing pelvic pain during your pregnancy, especially in the second half of pregnancy.

When should I go to the ER?

If you’re experiencing severe blood loss, you should seek emergency medical care immediately. Major blood loss carries several serious side effects to both you and your baby.

Can I exercise with placenta previa?

Your healthcare provider will likely advise you to limit certain activities like exercise, squatting, jumping and lifting. These activities could cause bleeding. It’s best to discuss your day-to-day activities with your provider so they can suggest modifications as necessary.

Can I have sex if I have placenta previa?

Most healthcare providers will advise against having sexual intercourse if you have placenta previa. It’s best to avoid any activities that can trigger bleeding or contractions, like using tampons, douching or inserting anything into your vagina.