The National Institutes of Health estimates that anywhere from 20% to 80% of women develop muscular tumors called fibroids (also called leiomyomas or myomas) by the time they turn 50. While fibroids don’t usually require treatment, if they cause heavy bleeding, pain, or impact your ability to get pregnant, then treatment may be necessary. But the more information you have about fibroids — and how they can impact your health — the better.
- What uterine fibroids are and what causes them
- Who’s most likely to develop uterine fibroids
- How uterine fibroids can be treated
- How uterine fibroids may impact your fertility
What are uterine fibroids?
Technically, uterine fibroids are tumors, but they’re almost always benign (not cancerous). They can develop in a variety of ways, including inside, outside, or in the muscle of the uterus. Fibroids often grow differently — sometimes as a solitary tumor or sometimes in clusters. They can range in size from as small as a seed to as big as a grapefruit.Fibroids are connected to two hormones: estrogen and progesterone. Since both of those hormones stimulate the growth of your uterine lining during your period, your estrogen and progesterone levels can dictate how many fibroids you get, and how big they are. (Once you hit menopause and your reproductive hormones decrease, fibroids tend to shrink.)
There are three types of fibroids:
- Intramural fibroids, which grow in the muscular uterine wall
- Submucosal fibroids, which grow inside the uterus
- Subserosal fibroids, which grow on the outside of the uterus
Of the three types of fibroids, submucosal fibroids are more likely to impact fertility because they live in the uterus — but, in some cases, simply removing the fibroid solves any related issues. (More on that later!)
Who gets uterine fibroids?
While uterine fibroids can happen to anyone with a uterus, there are a few contributing factors:
- Family history: You’re more than three times as likely to have uterine fibroids if your biological mother had them.
- Weight: There is a link between higher weights and increased risk of fibroids (up to two to three times higher than average) because of elevated estrogen levels.
- Age: In general, fibroids are most common in your 30s and 40s.
- Race: Black women are more likely to get fibroids than women of other racial groups — and those fibroids may come at a younger age, be larger, and have more symptoms. (This may be because of differences in endometrial thickness, or the lining of the uterus.)
- Other factors that could increase risk include: Starting your period at an early age; a vitamin D deficiency; a diet high in red meat and low in vegetables, fruit, and dairy; and alcohol consumption.
Symptoms of uterine fibroids
You can have fibroids without having symptoms, but there are a few things to watch out for:
- Heavy menstrual bleeding, as well as bleeding in between periods, is the most common symptom of uterine fibroids.
- Some people report anemia (a low blood count) as a result of heavy bleeding.
- Pain and extreme discomfort, both during and in between periods, might also be a sign of uterine fibroids.
- Bladder and bowel symptoms (i.e. frequency, urgency, and difficulty) could suggest uterine fibroids. (Location and size of the fibroids play a big role in whether or not these symptoms develop.)
Your doctor may find uterine fibroids during a pelvic exam, but if you’re having any possibly related symptoms, they may also order tests (like ultrasounds) to check for them visually.
Treating uterine fibroids
Uterine fibroids develop because of estrogen and progesterone hormone levels — when levels are high, they’re more likely to grow. On the flipside, like we mentioned earlier, menopause can cause uterine fibroids to shrink.
First and foremost: If you think you’re at risk for uterine fibroids, or if you’re experiencing any symptoms, talk to your doctor or another healthcare provider. If you're diagnosed with uterine fibroids, there are a number of ways to treat them—your doctor will support you in determining the right approach for you.
We’ve listed just a few treatment options below, but you can find a full list on Mayo Clinic:
- Watchful waiting: Since uterine fibroids aren't cancerous and often have mild symptoms , your doctor might recommend just keeping an eye on things.
- Medication: If you’re having unpleasant bleeding, your doctor may prescribe hormone-targeting medications to help control symptoms. Doctors may use hormonal birth control to help prevent uterine fibroids from growing — birth control may also control bleeding symptoms related to fibroids.
- Surgery: There are minimally invasive procedures to address fibroids, like embolization (where the blood flow to the fibroids is cut off, resulting in them shrinking and dying), as well as traditional surgeries, like a hysterectomy (removal of the uterus). A hysterectomy ensures your fibroids never grow back, but it also eliminates your ability to have children down the line. For patients that still want the option of pregnancy in the future, your doctor can perform a myomectomy (removal of fibroids) surgery.
Can fibroids impact fertility?
In many cases, you can have fibroids, still get pregnant, and carry a healthy baby to term. In fact, a recent study found that fibroids were only the sole cause of infertility in 1-2.4% of patients seeking help with conceiving.
That said, there are ways that fibroids can contribute to fertility issues. According to American Society for Reproductive Medicine:
- Fibroids may change the shape of the cervix, which can affect sperm entering the uterus.
- Fibroids may change the shape of your uterus, which can interfere with sperm movement and embryo development.
- Your fallopian tubes, which release eggs, can be blocked by fibroids.
- Fibroids can change blood flow to your uterus, which impacts the way an embryo implants into your uterine wall to develop into a fetus.
Going to the doctor can give you a better idea of whether you can expect fibroids to impact your ability to conceive.
Thinking about having children and worrying about uterine fibroids can seem overwhelming, but now that you’re equipped with the basics, you’ll be better prepared if you have to deal with them in the future.
This article was medically reviewed by Dr. Jessica Selter, MD, an OB-GYN at NewYork-Presbyterian Hospital.