After uterine fibroid embolization (UFE), fibroids lose their blood supply and begin to die. Over the following weeks and months, they shrink significantly, with most fibroids losing about 40 to 60% of their volume within the first six months. The dead tissue either gets gradually reabsorbed by the body or, in some cases, calcifies into a small, hard remnant. Here’s what that process looks like in detail.
How Fibroids Die After Embolization
During UFE, tiny particles are injected into the uterine arteries, the main blood vessels feeding the uterus and its fibroids. These particles lodge in the smaller blood vessels within and around the fibroids, cutting off their oxygen and nutrient supply. Without blood flow, the fibroid tissue undergoes what’s called ischemic necrosis: the cells starve and die.
This process begins immediately after the procedure, but it plays out over weeks. The fibroid doesn’t simply vanish. Instead, the dead tissue softens and the fibroid gradually collapses inward as the body’s immune system breaks it down and clears it away. Think of it less like removing a tumor and more like the body slowly dismantling one from the inside out.
The Shrinkage Timeline
Fibroid shrinkage is measurable on imaging within the first few months, though results vary depending on the size and number of fibroids. At the three-month mark, studies consistently show a median volume reduction of around 40 to 53%. By six months, most fibroids have shrunk by roughly 44 to 59%. The process continues beyond that: one study measured an average 67% volume reduction at 12 months.
These are averages, and the range is wide. Some fibroids shrink by more than 90%, while others lose only a small fraction of their volume. Larger fibroids tend to lose a greater absolute amount of tissue, but smaller fibroids sometimes achieve a higher percentage reduction. The shrinkage continues gradually for up to a year or more before stabilizing.
What Happens to the Remaining Tissue
Once a fibroid has been starved of blood, the dead tissue follows one of a few paths. Most commonly, the body slowly reabsorbs it. Immune cells move in, break down the necrotic tissue, and carry the debris away through the lymphatic system. Over time, the fibroid becomes smaller, softer, and less noticeable on imaging.
In other cases, the dead tissue doesn’t fully reabsorb but instead calcifies. Calcium deposits form within the remnant, turning it into a hard, shrunken mass. Calcified fibroids are generally inert and don’t cause symptoms, though in rare cases they can remain large enough to cause continued pressure. Microscopic examination of these remnants shows the hallmarks of the process: infarct-type necrosis, calcifications, and mild inflammation.
A third possibility, which occurs in roughly 3 to 12% of UFE cases, is spontaneous expulsion. This happens most often with submucosal fibroids, the type that grows into the uterine cavity. After losing their blood supply, these fibroids can detach from the uterine wall and pass through the cervix. Most expulsions happen without significant complications, though fibroids larger than 6 cm that migrate into the cavity sometimes require additional treatment.
When Symptoms Start to Improve
The symptom relief timeline doesn’t perfectly match the shrinkage timeline. Heavy menstrual bleeding, often the most disruptive symptom, typically begins improving within two to three menstrual cycles after the procedure. Each period tends to be lighter and shorter than the last during this window. Society of Interventional Radiology guidelines indicate that more than 90% of women should expect their abnormal bleeding to resolve.
Bulk-related symptoms like pelvic pressure, frequent urination, and constipation take a bit longer because they depend on the fibroid physically getting smaller. Initial improvement often begins within two to three weeks, but it can take up to three months to notice a meaningful change. Most people report complete relief from bulk symptoms by six months.
The First Week: Post-Embolization Syndrome
Before symptoms improve, there’s a recovery period that catches some people off guard. As the fibroids die, the body mounts an inflammatory response that produces a cluster of symptoms known as post-embolization syndrome. This typically includes pelvic pain and cramping, low-grade fever, nausea, fatigue, and vaginal discharge. It’s not a complication; it’s the expected response to tissue dying inside the body.
Post-embolization syndrome usually lasts two to seven days and is managed with pain relievers and anti-nausea medication. The cramping in the first 24 to 48 hours can be intense, often described as similar to severe menstrual cramps. After the first week, most people return to normal activities, though some mild fatigue may linger.
How Doctors Confirm It Worked
Follow-up imaging, usually an MRI with contrast dye, is the standard way to confirm that the embolization was successful. Doctors look at whether the fibroid tissue still “lights up” when contrast is injected. A fibroid that takes up no contrast at all is 100% infarcted, meaning completely dead. A successful outcome is defined as less than 10% residual contrast enhancement in the total fibroid burden. One study found that 96% of patients met this threshold.
If a fibroid still shows significant blood flow on follow-up imaging, it may have recruited new blood supply from collateral vessels, which can happen in a small percentage of cases. This is one reason some fibroids don’t shrink as expected.
Long-Term Outcomes and Retreatment
The long-term picture for UFE is generally favorable, though it isn’t a permanent solution for everyone. In the largest long-term study, which followed 200 patients for at least five years, 73% reported sustained symptom control over the full follow-up period. Other studies have reported five-year symptom control rates ranging from 65% to over 80%.
About 20% of patients in that same cohort required some form of retreatment within five years. This included repeat embolization, surgical fibroid removal, or hysterectomy. The hysterectomy rate across major long-term studies ranged from about 5% to 28%, depending on the study population. Retreatment is most often needed when existing fibroids weren’t fully infarcted or when new fibroids develop, since UFE treats the fibroids present at the time of the procedure but doesn’t prevent new ones from forming.
The American College of Obstetrics and Gynecology recommends UFE as a treatment option for patients who want to keep their uterus, with the caveat that data on future fertility after the procedure is still limited. For women whose primary goal is symptom relief rather than future pregnancy, it remains one of the most effective nonsurgical options available.