How HIFU works and why risks remain
HIFU stands for high-intensity focused ultrasound. Beams of sound pass through the skin and meet at one point inside the fibroid, where the heat destroys a small volume of tissue. HIFU treats the fibroid through the skin of the abdomen, without an incision. The heat still crosses the tissue beneath the skin on its way in, so risks remain.
MR-guided systems aim and monitor the beam inside an MRI scanner, which can map temperature. Ultrasound-guided systems use live ultrasound images. Podo Women's Clinic treats uterine fibroids with ultrasound-guided HIFU (high-intensity focused ultrasound) using the HIFUNIT9000 system. Which fibroids respond depends on their size and position and on how they look on imaging.
Is HIFU for fibroids safe?
Published reviews describe HIFU as generally safe in selected patients. HIFU fibroid side effects are mostly mild, and the reviews also note gaps. A review of 60 studies found major adverse events almost nonexistent and recorded no deaths, but it pointed out that long-term data were lacking (Ali et al., 2024). A review of 43 studies of MR-guided focused ultrasound put major events, such as skin ulceration or deep vein thrombosis, at 0.41 percent of cases (Kociuba et al., 2023).
NICE reviewed MR-guided focused ultrasound for fibroids and found the evidence on short-term efficacy and on safety adequate to support its use with normal clinical governance, while noting well-recognised complications and that further treatment may be required. It asks that patient selection involve a gynecologist and an imaging specialist, and that only clinicians with specific training in the technique perform it (NICE). That guidance concerns MR-guided systems.
HIFU fibroid side effects you are likely to notice
Lower abdominal pain or cramping, a sense of warmth or tenderness in the skin over the treated area, and vaginal discharge or light bleeding for some days. These usually settle without treatment.
A 2024 systematic review pooled 60 studies and counted side effects. Lower abdominal pain was reported in 38 percent of patients, abnormal vaginal discharge in 14.7 percent, leg numbness or tingling in 3.5 percent, vaginal bleeding in 1.7 percent and blood in the urine in 0.3 percent. Most events were mild and long-term data were lacking (Ali et al., 2024). These figures are not the rate at any one clinic.
Skin burns and abdominal scars
HIFU can cause skin burns or heat injury on the abdomen; you are monitored throughout, and aftercare instructions are given in English. In the 60-study review, skin burns, blisters or nodules were reported in 0.6 percent of patients and healed with conservative treatment. An earlier review of 34 studies and 27,802 patients, cited by the same authors, reported skin burns or blisters in 1.5 percent. In that review 26 women (0.26 percent) had more serious injury, two of whom needed damaged tissue removed surgically; the rest healed with creams in under two weeks (Ali et al., 2024).
Old abdominal scars matter. Ali and colleagues suggest that ultrasound energy can build up in scar tissue. In a Chinese study of ultrasound-guided treatment, abdominal scars, a thicker abdominal wall, fibroids in the upper part of the uterus (the fundus) and fibroids that looked bright or mixed on T2-weighted MRI were each linked to skin injury, as were higher power and longer treatment time (Chendian et al., 2024). A UK series reported a second-degree burn in a patient with a cesarean scar (Lyon et al., 2019). A meta-analysis of fibroids under 300 cubic centimeters found skin burns and sciatic nerve pain more common after ultrasound-guided HIFU than after MR-guided HIFU (Yu et al., 2021). Tell the doctor about any abdominal scar.
Nerve pain and leg numbness
Energy that reaches a nerve behind the uterus can irritate it. Pain, numbness or tingling in a leg or buttock is the usual sign, and sciatic nerve irritation is among the most commonly described events after MR-guided focused ultrasound (Kociuba et al., 2023). In a two-center study of 100 women treated with ultrasound-guided HIFU, two had temporary sciatic nerve irritation (Dohmen et al., 2025). Ali and colleagues note that the most serious nerve injury can take up to a year to recover.
Tell the doctor straight away if you feel burning or sharp pain in the skin, or pain that runs down a leg or into the buttock. These signs can mean that the energy or the aim needs to change. The doctor adjusts the energy and pauses as needed throughout the treatment.
Incomplete treatment and repeat procedures
HIFU heats the part of the fibroid the beam reaches. Tissue the heat does not reach stays alive, and new fibroids can form later. In a pooled analysis of 18 studies and 5,216 women, reintervention after HIFU was about 1 percent at one year, 7 percent at two years, 19 percent at three years and 29 percent at five years. It was lower after ultrasound-guided HIFU than after MR-guided treatment, and 3.45 times more likely for fibroids that were bright on T2-weighted MRI (Dou et al., 2024).
Compared with embolization, a 2022 meta-analysis found a higher reintervention rate after HIFU (relative risk 4.06), and no significant difference compared with surgery (Yan et al.). NICE advises that patients be told their symptoms may not be relieved, may return, and that further procedures may be required.
Pregnancy after HIFU for fibroids
NICE says the effects of the procedure on fertility and on pregnancy are uncertain. Reviews of the studies so far disagree. A systematic review of 21 studies counted 366 pregnancies after ultrasound-guided HIFU, with one fetal death in the womb, six cases of placenta previa and no uterine rupture, and concluded that outcomes appeared non-inferior to standard care but that a randomized trial was needed (Anneveldt et al., 2021). A 2025 meta-analysis found lower pregnancy and live birth rates after HIFU than after myomectomy and called for better-designed studies (Chen et al.).
On the ovaries and the uterine lining, a three-center study of ultrasound-guided HIFU found no significant change in anti-Müllerian hormone, a marker of ovarian reserve, six months after treatment (measured at one of the centers), and MRI showed no lasting injury to the lining (Zhou et al., 2024). If you plan a pregnancy, say so at the first consultation.
Who should not have HIFU
Doctors generally avoid HIFU when no clear beam path can be found, for example when bowel lies between the skin and the fibroid. HIFU candidates are chosen by scan, and a published European protocol also excluded suspected cancer of the uterus, pregnancy and acute inflammation (Dohmen et al., 2025).
HIFU is offered for fibroids up to about 12 cm in size and up to 12 fibroids in number. Subserosal fibroids that project outward from the surface of the uterus (pedunculated subserosal fibroids) are not treated with HIFU.
How risks are reduced
Before treatment, the size, type and location of each fibroid are assessed by ultrasound to decide whether HIFU is suitable. The clinic limits HIFU to two patients a day, and the doctor who performs your treatment also manages your aftercare.
Ask for a clear answer about how the skin is protected, how the energy is monitored and what happens if you feel pain during treatment.
Questions to ask before treatment
How many HIFU treatments does the clinic perform, and who performs them? Is my fibroid a good target, and why? Who reviewed my scan before treatment was offered? What happens if I feel pain during treatment? How will follow-up work once I am home? What happens if the fibroid needs a second treatment? Results and recovery vary from person to person. This page is general information and is not a diagnosis; a consultation is needed to decide whether a procedure suits you.
Questions
Does HIFU affect the ovaries or the lining of the uterus?
In a three-center study of ultrasound-guided HIFU, anti-Müllerian hormone, a marker of ovarian reserve, did not change significantly six months after treatment (measured at one of the centers), and MRI showed no lasting injury to the uterine lining (Zhou et al., 2024). Evidence on pregnancy after HIFU is still limited, so tell us if you plan one.
Could a growth that looks like a fibroid be something more serious?
Rarely, a growth that looks like a fibroid on imaging is a cancer of the uterine muscle called a sarcoma. ACOG notes that fibroids can rarely be associated with cancer. HIFU leaves the tissue in the body, so no sample goes to a laboratory. Doctors judge this risk from your history and imaging before treatment. Ask how it is assessed for you.
What is the FDA status of HIFU for fibroids?
The FDA granted premarket approval to an MR-guided focused ultrasound system for fibroids, the ExAblate 2000, in October 2004, for women who wanted to keep the uterus and had completed childbearing. The record lists later supplements, so the current labeling may differ. Podo uses an ultrasound-guided system, so that listing does not describe Podo's device, and this page makes no statement about its US regulatory status. Ask any clinic about the regulatory status of its machine in the country where you are treated.
Can I get pregnant after HIFU for fibroids?
Some women do, but no one can promise it. NICE says the effects on fertility and pregnancy are uncertain, and reviewers describe the studies of pregnancy after HIFU as varied in design and in need of better trials. Tell the doctor if you plan a pregnancy, because it affects which treatment is suitable.
Sources
- Ali et al., 2024: side effects of HIFU for fibroids, systematic review (PMC)
- Kociuba et al., 2023: adverse events after MR-guided focused ultrasound for fibroids, systematic review (PubMed)
- NICE HealthTech guidance HTG277 (formerly IPG413): MR-guided focused ultrasound for uterine fibroids, recommendations
- FDA premarket approval database, P040003: ExAblate 2000 system (MR-guided focused ultrasound)
- Dou et al., 2024: reintervention after HIFU for fibroids, meta-analysis (PubMed)
- Yan et al., 2022: HIFU compared with embolization and surgery for fibroids, meta-analysis (PubMed)
- Lyon et al., 2019: ultrasound-guided HIFU for fibroids, Ultraschall in der Medizin (PubMed)
- Chendian et al., 2024: factors linked to abdominal skin injury in ultrasound-guided focused ultrasound ablation of fibroids (PubMed)
- Yu et al., 2021: MR-guided and ultrasound-guided HIFU for fibroids under 300 cm3, meta-analysis (PubMed)
- Dohmen et al., 2025: ultrasound-guided HIFU for fibroids at two European centers, European Radiology (PubMed)
- Anneveldt et al., 2021: reproductive outcomes after HIFU for fibroids, systematic review (PubMed)
- Chen et al., 2025: reproductive outcomes of HIFU and myomectomy for fibroids, meta-analysis (PubMed)
- Zhou et al., 2024: ultrasound-guided HIFU for fibroids, Academic Radiology (PubMed)
- ACOG patient FAQ: Uterine fibroids
Read about this at Podo
HIFU fibroid recovery time in Korea: follow-up scans and flying home
About the reviewer
Dr. Mo Hyung-jin, MD, PhD, board-certified OB-GYN specialist, is the medical director of Podo Women's Clinic. He developed the pelvic ligament suspension technique used at the clinic for stress urinary incontinence and pelvic organ prolapse. Profile