What Is a Subserosal Fibroid?

A subserosal fibroid is a uterine fibroid that grows on the outside of the uterus and is almost always benign (not cancerous). Some subserosal fibroids are pedunculated (attached by a narrow stalk). While rarely dangerous, these growths can cause uncomfortable symptoms and interfere with nearby organ functions.

Also called just fibroids or leiomyomas, uterine fibroids in general are fairly common, affecting 50% to 80% of people who have uteruses at some point in their lives. They do not always cause symptoms, so it is possible to have them and not be aware of them.

Fibroids can develop as a single nodule (one growth) or in a cluster (a group of growths). Clusters can range in size from as small as 1 millimeter (0.04 inches) to as large as 20 centimeters (8 inches) in diameter or more. Uterine fibroids can grow as large as a watermelon.

This article covers the symptoms, causes, diagnosis, treatment, and prognosis of subserosal uterine fibroids.

Symptoms

Because of their location attached to the outer wall of the uterus, subserosal fibroids tend to interfere less with the functions of the uterus itself and more with neighboring organs, such as the bladder.

While heavy and/or prolonged menstrual bleeding is a common symptom of uterine fibroids, it is less common with subserosal fibroids.

Some symptoms of subserosal fibroids include:

• A feeling of heaviness or fullness in the lower abdomen/pelvis
• Frequent need to urinate
• Constipation
• Bloating
• Abdominal pain/cramping
• Enlargement of the lower abdomen
• Pain during sex
• Lower back/leg pain
• Inability to urinate/completely empty the bladder

Causes

An exact cause of fibroids hasn't been pinpointed, but some risk factors have been identified.

Age

The risk of fibroids increases with age, particularly from age 30 through menopause. Fibroids often shrink after menopause.

It is rare for fibroids to develop before a person has begun menstruating for the first time.

Beginning menstruation at an early age (younger than age 10) has been associated with a higher risk of fibroids later on, while late menstruation (older than age 16) has been associated with a decreased risk.

Family History

Having another family member or members who have experienced fibroids increases a person's risk of developing uterine fibroids. The risk is about three times higher than average if the family member gave birth to the person.

Ethnicity

Black people with uteruses are two to three times more likely than White people with uteruses to develop uterine fibroids.

Black people also respond differently than White people to standard medical treatment for fibroids. This is likely due to health disparities linked to medical racism.

More studies into the causes, diagnosis, and treatment of fibroids in Black people with uteruses need to be conducted, and medical protocols for uterine fibroids need to be adjusted to be more inclusive and effective for Black people.

Hormones

Uterine fibroids are affected by the levels of estrogen and progesterone (sex hormones).

The use of artificial hormones, such as those used in birth control pills, often slows down fibroid growth.

Body Size/Shape

It is believed that people with uteruses who are overweight are at higher risk of fibroids, particularly those who are very overweight.

A 2014 study yielded results that showed that the following were positively associated with uterine fibroids:

• Current body mass index
• Waist circumference
• Hip circumference
• Waist-to-height ratio
• Body fat mass
• Body fat percentage
• Intracellular water

According to the study, those who showed the highest risk were those with a higher:

• Body mass index
• Waist-to-height ratio
• Body fat percentage (greater than 30%)

While the association between being very overweight and having uterine fibroids has been shown by some research, it is unclear if being overweight is a cause of fibroids or just an association.

Diet

An increased incidence of uterine fibroids has been associated with eating a diet high in red meats (such as beef and ham).

The consumption of alcohol may also increase the risk of fibroids.

A diet low in fruits and vegetables has been associated with an increased risk of developing fibroids, while consuming dairy and citrus fruits appears to decrease the risk of fibroids.

Vitamin D deficiency, consumption of food additives, and the use of soybean milk may also increase the risk of uterine fibroids.

Childbirth

Never having given birth appears to increase the risk of developing fibroids in people who have uteruses, while those who have had multiple births tend to have a lower risk of fibroids.

Diagnosis

A primary healthcare provider may discover a uterine fibroid or fibroid cluster during a routine pelvic exam, which usually involves feeling the pelvic structures, including the uterus, from the outside with their fingers.

To give an idea of the size of the fibroid or fibroid cluster, a healthcare provider may compare it to common objects such as:

• Fruits (a grape, an orange, a melon, etc.)
• Nuts (an acorn, a walnut, etc.)
• Balls (small like a pingpong ball, medium like a baseball, or big like a basketball)

The healthcare provider will likely also run imaging tests to get a better view of the fibroid(s) and the pelvis.

These might include:

• Ultrasound
• Magnetic resonance imaging (MRI)
• X-rays
• Computed tomography (CT) scan
• Hysterosalpingogram (HSG): Injecting dye into the uterus and doing X-rays
• Sonohysterogram: Injecting water into the uterus and doing an ultrasound

Though not always necessary, surgery may be performed to make a conclusive diagnosis of fibroids. Most commonly, one of the following will be done:

• Laparoscopy: A long, thin scope (a bright light and camera) is inserted into a tiny incision made in or near the navel (belly button). The uterus and other organs are viewed on a monitor during the procedure, and pictures may be taken.
• Hysteroscopy: A long, thin scope with a light (and sometimes a camera) is inserted through the vagina and cervix into the uterus. This allows the healthcare provider to look inside the uterus without making an incision. Subserosal fibroids are on the outside of the uterus, not the inside, so it is likely another method would be used if a subserosal fibroid is suspected.

Treatment

Treatment for uterine fibroids is not always necessary and is usually given only if the fibroids are causing problematic symptoms. Sometimes healthcare providers take a "watchful waiting" approach, in which the fibroids are monitored for changes, instead of undertaking immediate treatment.

Several treatments are available for fibroids. Which one is used depends on factors such as:

• The location of the fibroid(s)
• The type of fibroid(s)
• The size of the fibroid(s)
• Severity of symptoms
• Age
• Personal health and health history
• Personal preferences
• Whether or not future pregnancy is desired

Hysterectomy

The most common treatment recommended by healthcare professionals for subserosal fibroids is hysterectomy.

Hysterectomy is a surgery that removes the uterus through an incision in the lower abdomen, through the vagina, or laparoscopically (using small incisions and a camera).

Some benefits of having a hysterectomy for fibroids include:

• It's considered safe and effective.
• It completely eliminates fibroids and their symptoms.
• It is the only way to guarantee fibroids won't return.

Some potential disadvantages of having a hysterectomy can include:

• Major surgery that requires anesthesia
• Possibility of surgery-related complications
• Two to six weeks of recovery time (depending on the type of procedure done to remove the uterus)
• Greater risk for urinary incontinence
• Reach menopause an average of two years earlier than those who have not had a hysterectomy
• Ends menstruation and childbearing

Types of hysterectomies include:

• Total hysterectomy: Removal of uterus and cervix
• Subtotal (also called a supracervical hysterectomy): Removal of the uterus but not the cervix

Surgeries that may be performed along with a hysterectomy include:

• Oophorectomy: Removal of an ovary
• Bilateral oophorectomy: Removal of both ovaries
• Bilateral salpingo-oophorectomy: Removal of the fallopian tubes and ovaries

These secondary surgeries are not always necessary. Removal of the ovaries along with the uterus causes menopause to begin immediately.

While hysterectomy is extremely effective, because of its physical and psychological risks, the National Institute for Health and Care Excellence (NICE) recommends that it should be considered only when:

• Other treatment options have failed, are contraindicated (should not be used), or are declined by the person with fibroids
• There is a wish for amenorrhea (lack of menstrual periods)
• The person with fibroids requests it after being fully informed about the procedure and its risks
• The person with fibroids does not wish to retain their uterus and fertility

Myomectomy

A myomectomy is a procedure that removes uterine fibroids but leaves the uterus intact.

Benefits of a myomectomy include:

• The uterus usually returns to functioning normally
• Pregnancy is possible
• Periods return/remain

Potential disadvantages of a myomectomy can include:

• New fibroids may grow after these fibroids are removed (especially in younger people with many fibroids)
• The surgery itself often takes longer than a hysterectomy
• Often more blood loss with a myomectomy than a hysterectomy
• Up to six weeks of recovery time
• Possibility of surgery-related complications
• Possible risks with future pregnancies (such as a cesarean section), depending on how deep the fibroids were and if any spanned a large part of the uterine wall

The three main types of myomectomy are:

• Open myomectomy: Fibroids are removed through an incision in the abdomen (may go up and down or across like a bikini cut). Usually used for very large fibroids.
• Minimally invasive laparoscopic myomectomy: This involves several small incisions (standard laparoscopic myomectomy), or one slightly larger incision (single port myomectomy).
• Hysteroscopic myomectomy: Removal of fibroids through the vagina using a camera with no incisions. Used for fibroids that protrude into the uterus, such as submucosal fibroids.

Uterine Fibroid Embolization (UFE)

UFE is a procedure for treating fibroids that is performed by an interventional radiologist.

During UFE, a thin catheter is inserted into the artery at the groin or wrist through an incision that is about the size of a pencil tip.

Small particles (about the size of grains of sand) are released through the catheter into the fibroid's blood supply. These particles float downstream and block the small blood vessels. This deprives the fibroid of nutrients. 

The procedure causes the fibroid to soften, bleed less, and shrink in size. About 90% of people who have UFE experience significant improvement in their symptoms, or the symptoms go away completely.

UFE is nonsurgical and minimally invasive, with a lower complication rate, less pain, less blood loss, and a shorter recovery time than surgical treatments for fibroids.

UFE is not recommended for people who:

• Have an active pelvic infection
• Have certain uncorrectable bleeding problems
• Have endometrial cancer
• Have extremely large fibroids
• Wish to preserve their fertility/are planning to get pregnant in the future
• Have larger uteruses
• Have pedunculated fibroids

Ultrasound Guided Radiofrequency Ablation

With this procedure, high-energy waves are used to generate heat that destroys fibroids.

The correct placement of the radiofrequency device within each fibroid is located and verified by ultrasound before ablation is performed.

The procedure is considered safe and is usually performed on an outpatient basis.

Magnetic Resonance Guided Focused Ultrasound (MRgFUS)

MRgFUS is a relatively new, noninvasive procedure that takes about three hours to complete.

The person with fibroids lies in a magnetic resonance imaging (MRI) machine, which a radiologist uses to identify and target the fibroids.

High-intensity ultrasound waves are then used while the person is in the MRI to heat and destroy the uterine fibroids. The procedure uses a device called the ExAblate.

MRgFUS has a low risk of complications and a short recovery time.

MRgFUS has some limitations, including:

• Lack of long-term studies
• Lack of studies on the effects on fertility and pregnancy
• Cannot treat all types of fibroids
• Cannot treat fibroids that are located near the bowel and bladder, or are outside of the imaging area
• Requires an extensive period of time involving MRI equipment
• Not covered by many insurance companies (which consider this procedure investigational, experimental, and unproven)

Medications

While medications don't cure fibroids, they can help manage fibroids and the symptoms that come with them.

Hormone Therapy

• Oral contraceptives (OCs): Sometimes used to control heavy menstrual bleeding but do not reduce fibroid growth
• Progestin-releasing intrauterine device (IUD): For fibroids that are in the uterus’s walls rather than in its cavity. Can relieve heavy bleeding and pain but not pressure (does not shrink fibroids).
• Gonadotropin-releasing hormone (Gn-RH) agonists: Lowers estrogen and progesterone levels, stopping menstruation, causing fibroids to shrink over several months. Can be used only for a few months. Side effects are similar to those of menopause.

Nonhormonal Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs): Ibuprofen (Motrin, Advil) or naproxen (Aleve). Treats cramping and pain caused by fibroids. Does not shrink fibroids. Should not be used at high doses for prolonged periods of time.
• Tranexamic acid (TXA): Helps boost the blood’s ability to clot, which helps decrease the amount of vaginal bleeding. Usually used in severe circumstances, such as heavy bleeding, and is generally not used long-term. Does not shrink fibroids or help with pain, but can prevent excessive bleeding and anemia.

Prognosis

Possible complications of fibroids include:

• Severe pain or very heavy bleeding (may require emergency surgery)
• Twisting of the fibroid (may require surgery)
• Anemia (low red blood cell count)
• Urinary tract infections
• Infertility (in rare cases)
• Kidney damage (in rare cases)

There is a small risk that fibroids may cause complications in pregnancy, depending on factors such as the size of the fibroid or fibroid cluster. These complications may include:

• Cesarean section delivery
• Breech presentation (baby enters the birth canal upside down, with feet or buttocks emerging first)
• Preterm birth or miscarriage
• Placenta previa (placenta covering the cervix)
• Postpartum hemorrhage (excessive bleeding after giving birth)

Coping

Fibroids often cause no symptoms at all and require no treatment or management.

If you have symptomatic fibroids, you should speak with a healthcare provider about treatment plans, as symptom management may not be enough.

To help cope with fibroid symptoms while waiting for treatment, you can:

• Take measures to relieve constipation and/or straining during a bowel movement, such as drinking water and eating high-fiber foods.
• Place a hot-water bottle or heating pad on your lower abdomen.
• Eat foods that are high in beta-carotene (such as sweet potatoes, spinach, carrots).
• Eat foods that are high in iron (like whole grains, spinach, shellfish, beans and lentils, pumpkin seeds, turkey, cashews, and dark chocolate).
• Eat high-fiber whole grains (such as buckwheat, spelt, oats, and rye).
• Exercise (don’t push yourself if you experience pain or discomfort).
• Take over-the-counter medications for pain relief, such as ibuprofen (Advil, Motrin), naproxen (Aleve), or acetaminophen (Tylenol).
• Check and manage your blood pressure if necessary (there is a correlation between high blood pressure and fibroids).
• Manage stress levels through relaxation techniques (yoga, massage, meditation, etc.).
• Avoid inflammatory foods, alcohol, and other foods that cause frequent urination or cramping.

Frequently Asked Questions

How do you shrink fibroids naturally with herbs?

As with any type of medication, always consult with a healthcare provider before using herbs or supplements.

Gui Zhi Fu Ling Tang (a combination of herbs) is the most common traditional Chinese medicine used for treating menstrual cramps and fibroids. It can be used by itself or with a standard treatment for fibroids.

Drinking green tea could be helpful in relieving fibroid symptoms. A 2013 study suggests that the flavanol EGCG, found in green tea, may reduce the size of uterine fibroids and improve symptoms of anemia and blood loss.

How fast do fibroids grow?

The growth of fibroids can vary and be difficult to predict.

One study indicated that average fibroid growth is 89% per 18 months. This means that a 2 centimeter fibroid (about the size of a blueberry) is likely to take about four to five years to double its diameter.

The study also found that very small fibroids tend to grow more quickly than larger ones. 

Why do fibroids cause heavy bleeding?

The pressure of the fibroid(s) against the uterine wall can cause the endometrial tissue whose lining is shed during menstruation to bleed more than usual.

Another factor may be that fibroids don’t allow the uterus to contract well enough to effectively stop menstrual bleeding.

Fibroids also produce growth factors (proteins) that stimulate the blood vessels of the uterus. This causes more blood in the uterine cavity, leading to heavier periods.

How do you deal with fibroids during pregnancy?

The hormones released during pregnancy to support the growth of the baby can also cause fibroids to get bigger.

Large fibroids can increase the risk of a breech birth by preventing the baby from being able to move into the correct fetal position.

Although rare, there may be a higher risk of a complications such as preterm delivery or a cesarean section.

If fibroids are discovered before or during pregnancy, the healthcare provider will monitor the fibroids for changes and complications.

A Word From Verywell

Uterine fibroids are common, and subserosal fibroids are the most common type of uterine fibroids. While they are often asymptomatic, subserosal fibroids can cause pain, discomfort, and other bothersome symptoms.

If you are experiencing symptoms of fibroids, make an appointment to see a healthcare provider, especially if you are or plan to become pregnant.

There are several effective treatments for subserosal fibroids that can get rid of fibroids for good or help manage their symptoms.