Here's what you need to know about these benign, but not necessarily harmless, tumors.
Uterine fibroids are benign (non-cancerous) tumors of the uterus. Fibroids are a common occurrence for women in their reproductive years.
Most women with uterine fibroids won’t have any symptoms, but some experience long periods and painful cramping. In severe cases, uterine fibroids can lead to infertility, pregnancy complications and miscarriage.
Fibroids are non-cancerous growths that develop in the uterus. The growths are made of smooth muscle cells and fibrous connective tissue of the uterus. The benign tumors can grow inside the muscle wall of the uterus (intramural), outside of it (subserosal) or in the uterine cavity (submucosal).
Uterine fibroids can be solitary or grow in groups. They can vary in size, from tiny seeds to large tumors the size of a watermelon. This growth can lead to additional health complications such as anemia and infertility.
There isn’t enough research to say for certain why fibroids develop, but scientists believe reproductive hormones, genetics, obesity and vitamin D deficiency are all contributing factors.
There are three main types of uterine fibroids. Depending on their size and location, the symptoms of fibroids can vary.
Subserosal fibroids are the most common type of fibroid. They grow from the outer wall of the uterus, which means they can have less impact on fertility and pregnancy, and more of an effect on neighboring organs, such as the bladder.
Common symptoms of subserosal fibroids may include:
Intramural fibroids grow in the muscle wall of the uterus and are commonly found growing in groups or clusters. If left untreated, intramural fibroids can have a negative impact on the bladder and bowels due to additional pressure from the tumors. They can cause a protruding abdomen.
This type of fibroid can interfere with a healthy pregnancy due to its potential size. The approach to treatment depends on your symptoms and fertility goals. If you have fibroids, chat with your doctor before trying to conceive to learn if your fibroids can affect your fertility or pregnancy and about your treatment options.
Submucosal fibroids, which are located on the inner wall of the uterus, are where a baby grows during pregnancy. This kind of fibroid can interfere with pregnancy. Submucosal fibroids can block fallopian tubes, impeding fertilization and implantation of a fertilized egg. They can interfere with embryo implantation and placental development.
If the fibroids grow large enough, they may obstruct the space the fetus needs during pregnancy, which could result in miscarriage or (rarely) birth deformities.
Symptoms for submucosal fibroids include:
Some people experience general pelvic pain, which tends to feel like pressure, heaviness and vague discomfort rather than a sharp, stabbing pain. Fibroids can also lead to feelings of abdominal fullness, which tends to appear as chronic fullness or pressure rather than occasional bloating.
Uterine fibroids may lead to painful sex. Generally, this feels like an internal aching pain during penetrative sex, known as deep dyspareunia. Plus, they can impact periods, leading to heavy, painful or long-lasting periods.
Fibroids are the most common gynecologic condition and the most common gynecologic diagnosis for inpatient hospitalizations.
Twenty to 25 percent of people who can get pregnant have fibroids—about 26 million people between the ages of 15 and 50. The majority are Black women: more than 80 percent develop this condition by age 50, and rates of hospitalization for fibroids are higher for Black women, according to a 2017 study.
Genetic factors, reproductive hormones like estrogen and progesterone or vitamin D deficiency can also increase your risk of fibroids.
If you think you might have fibroids, your doctor will perform an initial evaluation during a pelvic exam. This involves a full external and internal evaluation of your genital region.
Sometimes fibroids are large enough to feel during an internal exam. To conduct a pelvic exam, you will lie on your back on an exam table and put your feet in stirrups. Then, the doctor will insert two gloved fingers into your vagina and place their other hand on your lower abdomen, sandwiching your uterus between their hands to feel for any masses.
The doctor will insert a speculum into your vagina for visualization of the vaginal walls and cervix. Some health conditions present symptoms similar to fibroids. This visual check helps rule out those conditions. A rectal exam could be necessary to better evaluate a retroverted, or tilted, uterus.
Size, location, and accurate number are unable to be determined by the physical exam alone. A transvaginal ultrasound is often used. Other imaging technologies such as a hysteroscopy, a hysterosalpingogram (HSG), a sonohysterogram (SHG), a laparoscopy or magnetic resonance imaging (MRI) aren't generally used for diagnosis unless the ultrasound is unclear or they are being done as part of surgical and treatment planning.
Some fibroids don’t cause symptoms and may not require treatment. If you are having symptoms or uterine fibroid growth is causing fertility issues, there are different treatment options. Your options depend on the location of the fibroids, size and personal reproductive interests.
There are some medications designed to ease symptoms of fibroids, including over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) and birth control pills. Intrauterine devices (IUDs) can help reduce some of the symptoms, such as heavy bleeding or associated pain.
There are other surgical options, including uterine fibroid embolization (FBE), which shrinks fibroids by cutting off their blood supply, and ablation, which is the technical term for the removal or destruction of tissue, usually through radio waves or freezing temperatures.
Your doctor might also suggest a myomectomy, or the surgical removal of fibroids.
If medications and the least invasive options (embolization and myomectomy) aren’t working or won't work for your situation, your doctor might recommend surgical treatment. A hysterectomy, or the surgical removal of the uterus, is major surgery. It is the only way to eliminate the risk of future fibroids, but it also means you cannot get pregnant.
Fibroids aren’t thought to interfere with ovulation, depending on the size and location. But it is possible for fibroids to cause infertility or pregnancy loss.
If you have fibroids and are pregnant, they can be detected during a routine ultrasound or pelvic exam by an OB-GYN. Uterine fibroids generally don’t grow during pregnancy, but if it does happen, it will probably be in the first trimester, during which estrogen production is rapidly increasing.
Symptoms of fibroids during pregnancy may include pelvis and lower back pain, vaginal bleeding, and, in some cases, early miscarriage.
It’s rare for fibroids to grow during the second and third trimesters, but if they do, issues that may arise include placental abruption, preterm labor and fetal growth restriction.
Treatments for fibroids during pregnancy are limited because most surgeries and medications aren’t considered safe for pregnant people. Speak to your doctor about natural remedies and support if you’re worried.
The causes of fibroids aren’t fully known, but they have been linked to genetic factors and the production of reproductive hormones such as estrogen and progesterone.
A family history of uterine fibroids may put a woman at higher risk. Additionally, women who started menstruation at a younger age, drink alcohol, consume a diet high in red meat or low in fruit or vegetables or who suffer from vitamin D deficiency may be at increased risk.
Most fibroids don’t cause symptoms, so they don’t need treatment. If you do have symptoms, your doctor might suggest hormonal or non-hormonal medications or a myomectomy, which is the surgical removal of fibroids.
Other surgical options include a hysterectomy, the surgical removal of the uterus and a uterine artery embolization, which shrinks fibroids by cutting off their blood supply.
Most people who have fibroids won’t experience any symptoms. Some common symptoms include general pelvic pain, feelings of abdominal fullness, painful sex and heavy, painful or long-lasting periods.
In severe cases, uterine fibroids can also lead to infertility, pregnancy complications and miscarriage.
