What are Fibroids?
Fibroids, also known as uterine fibroids, myomas, or leiomyomas, are benign (non-cancerous) tumors made of muscle tissue that develop within the uterus. These growths can vary in size and number and may alter the shape or size of the uterus and, occasionally, the cervix.
Fibroids are very common, affecting a majority of women by menopause. Approximately 8 in 10 African American women and 7 in 10 Caucasian women will experience fibroids. Most fibroids do not cause symptoms or require treatment, but in some cases, their size and location within the uterus may lead to symptoms that require medical attention.
Types of Fibroids
Fibroids are generally classified based on their location within the uterus:
- Subserosal Fibroids: Located in the outer wall of the uterus, these make up about 55% of all fibroids.
- Intramural Fibroids: Found within the muscular layers of the uterine wall, accounting for approximately 40% of fibroids.
- Submucosal Fibroids: These grow into the uterine cavity and represent around 5% of fibroids.
Fibroids can also be pedunculated, meaning they are attached to the uterus by a stalk. They may occasionally occur in the cervix or attach to nearby organs such as the bladder and bowel through the surrounding ligaments.
Fibroids are rarely found outside the pelvic cavity.
Common Symptoms of Fibroids
Fibroid symptoms vary depending on their size and location within the uterus. While many women with uterine fibroids experience no symptoms, the most commonly reported symptoms include:Abnormal Uterine Bleeding
Pain and Cramping
Pelvic Pressure
Can Fibroids Affect My Fertility?
Impact on Fertility
Fibroids are a potential factor in infertility, affecting an estimated 5% to 10% of infertile women.
However, many women with fibroids do not experience infertility, and other potential causes should be considered and evaluated by a fertility specialist.
How Do Fibroids Cause Infertility?
The impact of fibroids on fertility depends on their size and location. Here are ways fibroids may reduce fertility:
- Location Matters: Submucosal fibroids (those in the uterine cavity) and large intramural fibroids (within the uterine wall and larger than 6 cm) are more likely to impact fertility.Fibroids can alter the shape of the cervix and uterus affecting sperm transit and embryo interaction with the uterine lining.
- Blockage of Fallopian Tubes: Fibroids can block the fallopian tubes, preventing eggs from reaching the uterus and inhibiting fertilization.
- Uterine Lining and Blood Flow: Fibroids may impact the uterine lining and decrease blood flow to the uterine cavity. This can reduce the likelihood of an embryo implanting and developing in the uterus.
For women undergoing IVF, fibroids may reduce pregnancy success rates, especially if they are large and/or protrude into the uterine cavity.
How are Fibroids Diagnosed?
Pelvic Exam. Uterine fibroids are often detected during a routine pelvic exam, which assesses the uterus's shape and size. However, a pelvic exam alone may not distinguish fibroids from ovarian masses or identify smaller fibroids, making additional imaging necessary. Blood Tests. In cases of irregular bleeding, blood tests can help determine if the bleeding is due to anovulation or other medical conditions.
Ultrasound. Ultrasound is typically the first tool used to diagnose fibroids. This imaging technique uses sound waves to create a picture of the pelvic organs. Both transvaginal and transabdominal ultrasounds may be used to account for fibroids of varying sizes and locations.
Sonohysterography (SHG). Also known as Saline Infusion Sonohysterogram (SIS), SHG is an ultrasound procedure in which a small amount of fluid is introduced into the uterus through a thin tube, enhancing visualization of fibroids that protrude into or distort the uterine cavity.
Hysterosalpingography (HSG). HSG uses X-rays to produce images of the inside of the uterus and check if the fallopian tubes are open. It can help identify fibroids that alter the shape of the uterine cavity or block the fallopian tubes.
Magnetic Resonance Imaging (MRI). MRI uses magnetic fields to produce detailed images. While not routinely used for fibroid diagnosis, it can be beneficial to map fibroid size and location, aiding in treatment planning.
Diagnostic Hysteroscopy. Diagnostic hysteroscopy involves inserting a small telescope-like instrument through the vagina and cervix into the uterus. It helps identify submucosal fibroids and other uterine cavity abnormalities.
For more information:
Treatment Options for Women Not Planning Pregnancy
If pregnancy is not part of your future plans, the following fibroid treatments are available:
Myolysis
- Myolysis is a surgery done with small tools and a camera, where heat or cold energy is used to destroy fibroids. This can be done with needles or lasers and is sometimes called radiofrequency ablation.
MRI-Guided Focused Ultrasound Surgery (MrgFUS)
- MRI-Guided Focused Ultrasound Surgery (MrgFUS) is a non-invasive treatment that uses MRI to help focus ultrasound energy on fibroids. Since it’s a newer technology, there isn’t much information about its long-term results, and it’s not recommended for people who want to have children in the future.
Uterine Artery Embolization (UAE)
- A Radiologist injects small particles into the blood vessels that supply the uterus. This blocks the blood flow to the fibroids, causing them to shrink. Patients might have pain for a few days after the procedure, and the fibroids usually shrink by 40-50%, which helps relieve symptoms. UAE is not recommended for people who want to have children in the future.
Hysterectomy
- About half of all hysterectomies are done to treat fibroids. A hysterectomy is surgery to remove the uterus and is a good option for women with symptoms who don’t plan to have children. The surgery can be done through the abdomen, the vagina, or with the help of small tools and a camera (laparoscopy). Recovery usually takes 2 to 6 weeks. It’s important to talk with your doctor about how this surgery might affect your overall health, emotions, and sexual well-being.
For more information:
Treatment Options for Women Planning Pregnancy
If you plan to get pregnant in the future, consider these fibroid treatment options:
Drug Therapy
- Hormonal Treatments: Some fibroids respond to estrogen levels and can be managed with medications such as Gonadotropin-releasing hormone (GnRH) analog injections, birth control pills, and progestins. However, these treatments may temporarily affect fertility and have potential side effects such as hot flashes, vaginal dryness, mood changes, and bone thinning.
Myomectomy Surgery for Fertility
For women planning pregnancy, myomectomy (surgical removal of fibroids) is often the most suitable treatment. Myomectomy can be done using various methods, depending on the location and size of the fibroids:
- Abdominal Myomectomy (Laparotomy): A 3-5 inch (or larger) incision is made in the abdomen to remove fibroids on the outer surface of the uterus and surrounding organs. Recovery time is 4-6 weeks.
- Laparoscopic Myomectomy: A lighted telescope (laparoscope) is inserted through a small incision near the belly button, and surgical instruments are used to remove the fibroids through additional small incisions. Recovery is usually 2-7 days.
- Hysteroscopic Myomectomy: Best for fibroids inside the uterus, this procedure removes fibroids inside the uterus using a lighted telescope (hysteroscope) inserted through the vagina. The uterus is inflated with fluid, and surgical instruments are inserted through the hysteroscope. Most patients return to normal activities within a few days.
- Robotic-Assisted Myomectomy: A telescope is inserted into the abdomen at or above the navel, and up to five small incisions hold the instruments used to remove the fibroids, controlled by robotic instruments. Recovery is typically between a few days and a week.
Do All Fibroids Require Treatment?
Not all fibroids require treatment, as most women with fibroids do not experience symptoms. However, regular check-ups are important to monitor the size and symptoms of the fibroids, especially for women planning pregnancy.
When is Surgery Considered?
Surgery is considered when fibroids cause significant symptoms or infertility. However, before opting for surgery, other potential causes of infertility should be thoroughly evaluated.
Is Surgery the Only Treatment?
Some fibroids, especially those responsive to estrogen, can be managed with medications such as GnRH analog injections, birth control pills, and progestins. While these can improve symptoms, they may temporarily affect fertility and have side effects. Non-surgical treatments like uterine artery embolization (UAE) and high-intensity focused ultrasound (HiFU) are less common and typically reserved for those who have completed childbearing.
When Can I Start Trying to Get Pregnant After a Myomectomy?
The uterus needs time to heal after surgery, and it may take 1-6 months before a woman is advised to attempt pregnancy.
What Is the Chance That Fibroids Will Return After Surgery?
There is about a 30% chance of new fibroids growing back within 10 years, especially for those with multiple fibroids.
What Happens to Fibroids During Pregnancy?
Most fibroids do not cause problems during pregnancy. However, some may grow larger, typically within the first 12 weeks, and cause complications. The biggest concerns related to fibroids during pregnancy include:
- Risk of Preterm Birth and Miscarriage: Fibroids can increase the likelihood of preterm birth or miscarriage, especially if they impact or distort the uterine cavity.
- Pain: Fibroids that outgrow their blood supply can cause severe pain.
- Baby's Position: Fibroids can affect the baby’s position in the uterus, raising the risk of a cesarean section, preterm delivery, and miscarriage.
- Delivery Issues: Fibroids can cause complications during delivery, such as bleeding or premature separation of the placenta from the uterus.
Pregnancy after Fibroid Surgery
The chances of becoming pregnant after fibroid surgery are similar to those for women in the general population in most cases. Removing fibroids that impact or distort the uterine cavity can increase the likelihood of becoming pregnant, and can reduce the risk of miscarriage and other obstetric complications. Depending upon the nature and extent of the procedure used to remove fibroids, delivery by Cesarean section may be recommended for subsequent pregnancies. Recommended timing and method of delivery after fibroid removal should be discussed with your physician.
Delivery Considerations
If a woman conceives after having a fibroid removed, she should discuss her history with the obstetrician who will deliver the baby. A cesarean section may be recommended, as strong labor contractions during vaginal delivery could increase the risk of uterine rupture and complications for both the mother and baby.
Read the Fibroids and Fertility fact sheetFind an Expert
Fibroids or Myomas or Leiomyomas
Treatment of uterine fibroids
Do all fibroids require treatment? Not usually, because most patients with fibroids do not have symptoms. View the fact sheet
What are fibroids?
Uterine fibroids (also called myomas or leiomyomas) are benign (noncancerous) tumors of muscle tissue found in the uterus. View the fact sheet
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