What Is the Fundus of the Uterus and Why Is It Important?

The uterus plays an essential role in reproductive health, from menstruation and implantation to pregnancy and childbirth. However, it has several distinct parts, each with an important purpose. One of these is the fundus of the uterus, the rounded upper portion of the uterus that helps support several reproductive processes.

The uterine fundus is particularly important during pregnancy because healthcare providers use its position to monitor uterine growth. It also contains muscular tissue that contributes to uterine contractions during labor. However, conditions such as uterine fibroids can develop in this area and sometimes affect its shape, size, or function.

Understanding the fundus of the uterus can help you better understand your reproductive anatomy, pregnancy monitoring, and certain uterine conditions.

What Is the Fundus of the Uterus?

The fundus of the uterus is the uppermost, rounded portion of the uterus, located above the openings of the fallopian tubes. It is opposite the cervix, which forms the lower, narrow part of the uterus and connects to the vagina.

The uterus is often described as an upside-down pear. In this comparison, the fundus is the broad, rounded top, while the cervix is the narrower bottom.

The fundus is part of the uterine body and contains muscular tissue that helps the uterus expand during pregnancy and contract during childbirth.

Where Is the Uterine Fundus Located?

The uterine fundus is located in the upper part of the uterus, within the pelvic cavity when a person is not pregnant. It sits above the main body of the uterus and near the points where the fallopian tubes connect.

During pregnancy, the uterus expands and rises out of the pelvis. As it grows, the fundus gradually moves upward into the abdomen.

Its changing position allows healthcare providers to estimate uterine growth during prenatal appointments.

What Are the Main Parts of the Uterus?

To understand the fundus, it helps to know the other major parts of the uterus.

Fundus: The rounded upper portion of the uterus, above the openings of the fallopian tubes.

Corpus: The main central body of the uterus, where a fertilized egg typically implants and pregnancy develops.

Isthmus: The narrower section connecting the uterine body to the cervix.

Cervix: The lower part of the uterus that opens into the vagina.

The uterine wall also contains three layers:

Endometrium: The inner lining that thickens during the menstrual cycle and sheds during menstruation if pregnancy does not occur.

Myometrium: The thick middle layer of smooth muscle that allows the uterus to stretch and contract.

Perimetrium: The thin outer covering that protects the uterus.

These structures work together to support menstruation, pregnancy, and childbirth.

What Does the Fundus of the Uterus Do?

Although the fundus does not function independently of the rest of the uterus, its location and muscular structure make it important to reproductive health.

1. Supports Uterine Expansion During Pregnancy

As a pregnancy progresses, the uterus expands to accommodate the developing fetus. The fundus moves upward as the uterus grows, making it a useful anatomical landmark during prenatal examinations.

2. Helps Healthcare Providers Monitor Pregnancy

Healthcare providers may measure fundal height during the second and third trimesters. This measurement helps assess whether the uterus is growing as expected for the stage of pregnancy.

3. Contributes to Uterine Contractions During Labor

The fundus contains a substantial amount of uterine muscle. Along with the rest of the myometrium, it participates in coordinated contractions that help the cervix dilate and move the baby through the birth canal.

4. Provides a Location for Placental Attachment

The placenta can attach to different areas of the uterine wall, including the fundus. A fundal placenta means the placenta is attached near the top of the uterus. This is generally a normal placental location, although the full placental position must be evaluated during pregnancy.

What Is Fundal Height During Pregnancy?

Fundal height is the measurement from the top of the pubic bone to the highest point of the uterus, known as the fundus. Healthcare providers commonly measure it during prenatal appointments to help monitor uterine growth.

The measurement is usually taken with a measuring tape while the patient is lying down.

How Does Fundal Height Change During Pregnancy?

As the uterus grows, the fundus gradually rises:

Around 12 weeks: The fundus is generally near the pubic bone.

Around 20 weeks: The fundus is typically near the belly button.

Around 20–36 weeks: Fundal height in centimeters often roughly corresponds to the number of weeks of pregnancy, with normal variation.

Around 36 weeks: The fundus usually reaches its highest position near the breastbone.

Near delivery: The fundus may move lower as the baby descends into the pelvis.

Fundal height is only one part of prenatal monitoring. If the measurement is larger or smaller than expected, your provider may recommend an ultrasound or other evaluation. Factors such as fibroids, fetal position, multiple pregnancy, and differences in amniotic fluid volume can affect the measurement.

Can Uterine Fibroids Affect the Fundus of the Uterus?

Yes. Uterine fibroids can develop in different areas of the uterus, including the fundus. These noncancerous growths are made of uterine muscle and connective tissue.

A fibroid that develops in the fundal region is commonly called a fundal fibroid. Depending on its size and exact location, it may change the shape of the uterus or cause symptoms.

Types of Fibroids That Can Develop Near the Fundus

Fundal fibroids can grow in different layers or areas of the uterine wall:

Intramural fibroids: Develop within the muscular wall of the uterus.

Submucosal fibroids: Grow toward the inner uterine cavity and may affect the shape of the cavity.

Subserosal fibroids: Develop near the outer surface of the uterus and may grow outward.

Symptoms of Fundal Fibroids

Some women with fundal fibroids have no noticeable symptoms. Others may experience:

Heavy or prolonged menstrual bleeding

Pelvic pain or pressure

Lower back pain

Abdominal fullness or swelling

Frequent urination

Pain during sexual intercourse

Fatigue associated with iron-deficiency anemia from heavy bleeding

Symptoms often depend on the fibroid’s size, number, and location.

Can Fundal Fibroids Affect Pregnancy?

Many women with uterine fibroids have healthy pregnancies. However, the effects can vary depending on the size, number, and location of the growths.

Larger fibroids or those that distort the uterine cavity may be associated with certain pregnancy complications. These can include pain, abnormal fetal positioning, preterm birth, or an increased likelihood of cesarean delivery in some cases.

Fundal fibroids may also make fundal height measurements more difficult to interpret because they can change the size or shape of the uterus.

If you have fibroids and are planning a pregnancy or are already pregnant, discuss appropriate monitoring with your obstetrician.

How Are Conditions Affecting the Uterine Fundus Diagnosed?

Healthcare providers may use a combination of examinations and imaging tests to evaluate the fundus and identify possible uterine abnormalities.

Common diagnostic methods include:

Pelvic examination: A healthcare provider may assess the uterus for enlargement, tenderness, or irregularities.

Pelvic ultrasound: Uses sound waves to examine the uterus, identify fibroids, and evaluate their size and location.

Transvaginal ultrasound: Provides detailed images of the uterus and surrounding reproductive structures.

MRI: May be recommended when additional information about fibroid size, number, or location is needed.

Your provider will recommend the appropriate tests based on your symptoms, medical history, and examination findings.

What Treatments Are Available for Fundal Fibroids?

Treatment for fundal fibroids depends on their size, location, symptoms, and whether you plan to become pregnant.

Options may include:

Watchful Waiting

If fibroids are small and do not cause symptoms, your healthcare provider may recommend monitoring them rather than starting treatment immediately.

Medication

Certain medications can help manage heavy menstrual bleeding, pelvic discomfort, or other symptoms. Some treatments may temporarily reduce fibroid size, but medication does not necessarily eliminate fibroids.

Myomectomy

A myomectomy is a surgical procedure that removes fibroids while leaving the uterus in place. It may be considered for women with symptomatic fibroids, including those whose fibroids affect the uterine cavity.

Uterine Fibroid Embolization (UFE)

Uterine Fibroid Embolization is a minimally invasive, nonsurgical procedure that reduces blood flow to fibroids, causing them to shrink over time.

During UFE, an interventional radiologist guides a small catheter into the blood vessels supplying the fibroids and injects tiny particles to block their blood supply.

UFE can help reduce symptoms such as heavy menstrual bleeding and pelvic pressure while preserving the uterus. However, preserving the uterus does not guarantee future fertility or pregnancy outcomes. Women who wish to become pregnant should discuss the potential benefits and risks of UFE with their healthcare providers.

When Should You See a Doctor?

Changes in menstrual bleeding, persistent pelvic discomfort, or symptoms of an enlarged uterus should be evaluated by a healthcare professional.

Consider scheduling an appointment if you experience:

Periods that are unusually heavy or last longer than normal

Persistent pelvic pain or pressure

Frequent urination without an obvious explanation

Abdominal enlargement or fullness

Pain during intercourse

Difficulty becoming pregnant

Seek urgent medical attention for very heavy bleeding, fainting, severe sudden pelvic pain, or other concerning symptoms.

Early evaluation can help identify the cause of your symptoms and determine whether treatment is needed.

Frequently Asked Questions

1. Is the fundus the top or bottom of the uterus?

The fundus is the topmost, rounded portion of the uterus. It is located above the openings of the fallopian tubes and opposite the cervix.

2. What is the normal position of the uterine fundus?

The fundus is normally located at the upper end of the uterus. Its position changes during pregnancy as the uterus expands and rises into the abdomen.

3. Does the fundus move during pregnancy?

Yes. As the uterus grows, the fundus gradually moves upward. Healthcare providers monitor its position and measure fundal height during prenatal appointments.

4. What does a fundal fibroid mean?

A fundal fibroid is a noncancerous growth that develops in the upper portion of the uterus. Its symptoms and potential effects depend on its size, number, and exact location.

5. Can fibroids make fundal height inaccurate?

Yes. Fibroids can change the size or shape of the uterus, which may affect fundal height measurements. Your healthcare provider may recommend an ultrasound to evaluate uterine and fetal growth more closely.

6. Is a fundal placenta normal?

A fundal placenta is attached near the top of the uterus. This is generally a normal location, but your healthcare provider will evaluate placental position and other pregnancy findings during ultrasound examinations.

7. Can you feel the fundus of your uterus?

During pregnancy, the fundus may become easier to feel as the uterus grows out of the pelvis. Healthcare professionals are trained to locate it during examinations. Avoid relying on self-examination to assess pregnancy or diagnose a uterine condition.

Learn More About Your Uterine Health with USA Fibroid Centers

The fundus of the uterus plays an important role in reproductive health, pregnancy monitoring, and childbirth. However, when fibroids develop in this area, they may change the shape of the uterus and contribute to symptoms such as heavy periods, pelvic pressure, and abdominal discomfort.

If you have been diagnosed with uterine fibroids or are experiencing symptoms, learning about your treatment options is an important step toward managing your health.

At USA Fibroid Centers, our specialists offer Uterine Fibroid Embolization (UFE), a minimally invasive treatment designed to shrink fibroids and help relieve symptoms without surgery.

Contact USA Fibroid Centers to learn whether UFE may be an appropriate treatment option for you.