Understanding uterine fibroids.
A comprehensive, evidence-based guide to uterine fibroids for Australian women. From FIGO classification through treatment options, fertility impact by type, and the Australian healthcare context.
What are uterine fibroids?
Uterine fibroids (leiomyomata) are benign smooth muscle tumours that grow in or on the uterus. They are the most common benign tumour in women of reproductive age and are composed of monoclonal smooth muscle cells surrounded by an extracellular matrix of collagen, fibronectin, and proteoglycan.
Fibroids are hormonally responsive. They depend on oestrogen and progesterone for growth, which is why they develop during the reproductive years, often enlarge during pregnancy, and typically shrink after menopause. Their growth is not driven by a single factor but by a complex interplay of genetics, hormones, and growth factors.
Stewart EA, N Engl J Med, 2015; Bulun SE, N Engl J Med, 2013
How do they develop?
Genetic mutations
Approximately 70% of fibroids carry somatic mutations in the MED12 gene (mediator complex subunit 12). These mutations are acquired in a single cell and drive its clonal expansion into a fibroid. Each fibroid within the same uterus arises from a separate mutation event, meaning each is genetically distinct.
Makinen et al., Science, 2011; Mehine et al., N Engl J Med, 2013
Hormonal dependence
Both oestrogen and progesterone promote fibroid growth. Oestrogen stimulates cell proliferation, while progesterone activates growth factors and inhibits apoptosis. This dual hormonal dependence explains why fibroids are most active during the reproductive years and why treatments that reduce oestrogen or block progesterone can shrink them.
Bulun SE, N Engl J Med, 2013; Ishikawa et al., Endocr Rev, 2010
Genetic predisposition
Having a first-degree relative with fibroids increases your risk approximately 2.5-fold. African-descent women have a 2-3 times higher prevalence and tend to develop fibroids at younger ages, with larger and more numerous tumours. Genome-wide association studies have identified multiple susceptibility loci, though no single gene explains the condition.
Baird et al., Am J Obstet Gynecol, 2003, PMID 12548202; Eggert et al., Hum Reprod, 2012
Risk and protective factors
Established risk factors include early menarche, nulliparity, obesity (adipose tissue produces oestrogen), and hypertension. Protective factors include increasing parity and use of combined hormonal contraceptives (which suppress endogenous hormone levels). Age is the strongest risk factor: prevalence rises sharply from the late 20s through to the mid-40s.
Wise et al., Epidemiol Rev, 2005; Laughlin et al., BJOG, 2010
Prevalence
Stewart EA, N Engl J Med, 2015
Pritts et al., J Minim Invasive Gynecol, 2015
Pritts et al., J Minim Invasive Gynecol, 2015; Parker et al., Obstet Gynecol, 1994
FIGO classification system
The International Federation of Gynecology and Obstetrics (FIGO) classifies fibroids by their position relative to the uterine wall. This system is critical because the location of a fibroid, rather than its size alone, determines the symptoms it causes and the treatment options available.
Munro et al., Int J Gynaecol Obstet, 2011 (FIGO classification)
0Pedunculated intracavitary
Completely within the uterine cavity, attached by a stalk.
Completely within the uterine cavity, attached by a stalk
Heavy bleeding, most symptomatic type per size
1Submucosal (>50% intracavitary)
Mostly within the cavity, less than 50% within the myometrium.
Mostly within the cavity, less than 50% within the myometrium
Heavy menstrual bleeding, intermenstrual bleeding
2Submucosal (<50% intracavitary)
Mostly within the myometrium, less than 50% projecting into the cavity.
Mostly within the myometrium, less than 50% projecting into the cavity
Heavy bleeding, may distort cavity
3Intramural (contacts endometrium)
Entirely within the myometrium but touches the endometrial lining.
Entirely within the myometrium but touches the endometrial lining
May cause heavy bleeding, debated fertility impact
4Intramural
Entirely within the myometrium, no contact with endometrium or serosa.
Entirely within the myometrium, no contact with endometrium or serosa
Bulk symptoms if large, often asymptomatic
5Subserosal (>50% intramural)
Mostly within the myometrium, less than 50% projecting beyond the serosal surface.
Mostly within the myometrium, less than 50% projecting beyond the serosal surface
Bulk and pressure symptoms
6Subserosal (<50% intramural)
Mostly on the outer surface, less than 50% within the myometrium.
Mostly on the outer surface, less than 50% within the myometrium
Pressure on bladder or bowel, minimal bleeding effect
7Pedunculated subserosal
Attached to the uterine surface by a stalk, projects outward.
Attached to the uterine surface by a stalk, projects outward
Pressure symptoms, torsion risk (rare)
Munro et al., Int J Gynaecol Obstet, 2011
Symptoms and their impact
Roughly 50-75% of fibroids are asymptomatic and only discovered incidentally on imaging. When symptoms do occur, they fall into two main categories: abnormal uterine bleeding and bulk-related symptoms. The type, number, and location of fibroids determine which symptoms predominate.
Stewart EA, N Engl J Med, 2015; Donnez and Dolmans, N Engl J Med, 2023
Symptom prevalence in women with symptomatic fibroids
Bleeding symptoms
The hallmark symptom, particularly with submucosal fibroids. Bleeding may be heavy enough to require changing protection hourly, passing large clots, or causing iron-deficiency anaemia. The mechanism involves increased endometrial surface area, disrupted endometrial vasculature, and impaired uterine contractility.
Periods lasting longer than seven days. Women may experience bleeding throughout much of the month, with only a short interval between cycles.
Bleeding or spotting between periods, more common with submucosal fibroids that distort the uterine cavity.
A frequent consequence of chronic heavy bleeding. Symptoms include fatigue, breathlessness, pallor, dizziness, and reduced exercise tolerance. Anaemia can significantly impact daily functioning and quality of life.
Stewart EA, N Engl J Med, 2015; Munro et al., Best Pract Res Clin Obstet Gynaecol, 2017
Bulk and pressure symptoms
A sensation of fullness, heaviness, or pressure in the lower abdomen. Large fibroids can make the uterus palpable above the pubic bone.
Anterior fibroids pressing on the bladder cause urinary frequency, urgency, and difficulty emptying the bladder completely. Large fibroids can cause ureteric compression (rare).
Posterior fibroids can press on the rectum, causing constipation, a feeling of incomplete emptying, or rectal pressure.
Very large fibroids or a significantly enlarged uterus can cause visible abdominal swelling. Some women are mistakenly thought to be pregnant.
Donnez and Dolmans, N Engl J Med, 2023; Stewart EA, Lancet, 2001
Pain
Fibroids themselves are generally not painful. When pain does occur, it typically results from red degeneration (during pregnancy or with rapid growth), torsion of a pedunculated fibroid, or secondary dysmenorrhoea from heavy bleeding. Chronic pelvic pain is less commonly attributed to fibroids and warrants investigation for other causes such as endometriosis or adenomyosis.
Stewart EA, N Engl J Med, 2015
Getting diagnosed
Fibroids are often diagnosed during investigation of heavy menstrual bleeding, pelvic pressure, or incidentally during imaging for other reasons. The diagnostic approach aims to confirm the presence of fibroids, classify them by FIGO type, and exclude other pathology.
Imaging modalities
Transvaginal ultrasound (TVUS)
The first-line imaging modality for suspected fibroids. Transvaginal ultrasound has a sensitivity of 95-100% for detecting fibroids larger than 2cm. It can determine size, number, and general location. Limitations include difficulty distinguishing between intramural and submucosal fibroids, and reduced accuracy when the uterus is very large or contains many fibroids.
Dueholm et al., Acta Obstet Gynecol Scand, 2002; Vitiello and McCarthy, Semin Reprod Med, 2010
Saline infusion sonography (SIS)
Saline is infused into the uterine cavity during ultrasound to outline submucosal fibroids. This technique is particularly valuable for determining how much of a submucosal fibroid is intracavitary versus intramural, which directly affects surgical planning. It distinguishes type 0 from type 1 and type 2 fibroids more accurately than standard ultrasound.
Becker et al., Best Pract Res Clin Obstet Gynaecol, 2008
MRI
Magnetic resonance imaging is the most accurate modality for mapping fibroids and is used when TVUS findings are complex, the uterus is very large, or surgical planning requires detailed anatomy. MRI can accurately determine the number, size, type, and relationship of fibroids to the endometrial cavity and the serosal surface. It is also the best imaging tool for distinguishing fibroids from adenomyosis or, rarely, leiomyosarcoma.
Dueholm et al., Acta Obstet Gynecol Scand, 2002; Murase et al., Radiology, 1999
Hysteroscopy
Direct visualisation of the uterine cavity using a small camera. Most valuable for evaluating and simultaneously treating submucosal fibroids. It allows the clinician to assess the extent of intracavitary protrusion and plan resection. Often combined with treatment (see-and-treat approach).
AAGL Practice Report, J Minim Invasive Gynecol, 2012
Standardised reporting
Munro et al., Int J Gynaecol Obstet, 2011
Treatment options
Treatment depends on symptom severity, fibroid type and location, whether fertility preservation is a priority, and your preferences. Asymptomatic fibroids generally do not require treatment. For symptomatic fibroids, options range from medical management through to minimally invasive procedures and surgery.
Stewart EA, N Engl J Med, 2015; RANZCOG, 2022
The levonorgestrel intrauterine system reduces heavy menstrual bleeding by up to 90% by thinning the endometrial lining. Effective for bleeding symptoms regardless of fibroid type, though insertion may be difficult if the cavity is significantly distorted. Does not shrink fibroids but effectively manages the bleeding they cause.
Sangkomkamhang et al., Cochrane Database Syst Rev, 2013
An antifibrinolytic that reduces menstrual blood loss by approximately 40-50%. Taken only during heavy bleeding days (not continuously). Does not affect fibroid size. Useful as a non-hormonal option or as an adjunct to other treatments. Generally well tolerated with a good safety profile.
Lukes et al., Obstet Gynecol, 2010; Bryant-Smith et al., Cochrane Database Syst Rev, 2018
May reduce menstrual bleeding volume and can be taken continuously to reduce the frequency of periods. Does not shrink fibroids. Limited evidence for fibroids specifically, but commonly used when fibroids coexist with other menstrual symptoms.
Donnez and Dolmans, N Engl J Med, 2023
Create a temporary, reversible menopause-like state, shrinking fibroids by 30-50% within 3-6 months. Used primarily as pre-surgical preparation to reduce fibroid size and correct anaemia before myomectomy. Limited to short-term use (3-6 months) due to bone density loss and menopausal side effects. Add-back HRT can mitigate side effects.
Lethaby et al., Cochrane Database Syst Rev, 2001
A newer class of oral medications that offer dose-dependent oestrogen suppression. Relugolix combination therapy (with add-back oestrogen and progestin) reduced heavy menstrual bleeding in over 70% of women in phase 3 trials while maintaining bone density. These represent an important emerging option for longer-term medical management. Regulatory approvals are progressing in Australia.
Al-Hendy et al., N Engl J Med, 2021; Stewart et al., N Engl J Med, 2021
A selective progesterone receptor modulator that was effective in shrinking fibroids. Its use has been significantly restricted or suspended in most jurisdictions due to rare but serious cases of liver injury. In Australia, access is limited. Discuss current availability with your specialist if this option has been raised.
EMA safety review, 2020; Donnez et al., N Engl J Med, 2012
Parker et al., Obstet Gynecol, 1994
Living with fibroids
For many women, fibroids require practical day-to-day management alongside, or instead of, medical treatment. Iron management, bleeding pattern awareness, and knowing when to seek review are all important parts of living well with fibroids.
Iron-deficiency anaemia is the most common consequence of heavy menstrual bleeding from fibroids. Many women adapt to gradually worsening anaemia and do not recognise how much it affects them until their iron levels are corrected.
Iron replacement
Oral iron supplements (ferrous fumarate, ferrous sulfate) are first-line. Taking iron with vitamin C and on an empty stomach improves absorption. Alternate-day dosing may be better tolerated and similarly effective to daily dosing. Intravenous iron infusion is appropriate when oral iron is not tolerated, levels are very low, or rapid correction is needed (e.g., before surgery).
Stoffel et al., Lancet, 2020; Munoz et al., Lancet Haematol, 2018
Monitoring
Check ferritin levels (not just haemoglobin) every 3-6 months during treatment. A ferritin below 30 indicates depleted iron stores even if haemoglobin is within the normal range. Target ferritin above 50 for symptom improvement. Women with ongoing heavy bleeding may need continuous supplementation.
Myths vs evidence
Fibroids are common, and so are misconceptions about them. Tap each card to see what the evidence actually says.
Fibroids and fertility
If fertility is part of your plan
This section covers how fibroids can affect fertility, broken down by FIGO type. If fertility is not currently relevant to you, feel free to skip ahead.
Fibroids and pregnancy
If pregnancy is relevant to you
This section covers pregnancy-related considerations for women with fibroids. Skip to the next section if this is not currently relevant.
Fibroids after birth
If postpartum is relevant to you
This section covers what to expect with fibroids after birth. Skip ahead if this is not currently relevant.
Questions for your doctor
Tick off questions as you discuss them. You can screenshot or print this list to bring to your appointment.
Diagnosis
Treatment options
Fertility
Pregnancy
Follow-up
The Australian context
Uterine fibroids are the most common indication for hysterectomy in Australia and carry a substantial healthcare burden. However, awareness of non-surgical options remains limited, and there are significant gaps in prevalence data for Australian women.
PBS access to medications
GnRH agonists (goserelin, leuprorelin): PBS-listed for specific indications including pre-surgical preparation for myomectomy or hysterectomy, and for management of anaemia due to fibroid-related bleeding. Authority prescription required. Typically approved for 3-6 month courses.
Tranexamic acid: PBS-listed for heavy menstrual bleeding. Available without authority prescription. Low cost with PBS subsidy.
Oral GnRH antagonists: Not yet PBS-listed in Australia as of early 2026. Relugolix combination therapy has been approved in the US and Europe. TGA and PBAC submissions are anticipated. If approved, this would provide an important new long-term medical management option.
Ulipristal acetate: TGA registration has been suspended following European safety concerns regarding liver injury. Not currently available in Australia.
PBS Schedule, 2025; TGA, 2025
MBS imaging and procedures
Pelvic ultrasound: Medicare rebate available when referred by a GP or specialist. Both transabdominal and transvaginal components are covered. Gap fees vary by provider.
MRI: Medicare rebate available when referred by a specialist for specific clinical indications. Pre-surgical mapping for complex fibroid cases is generally covered. GP referrals for MRI are not eligible for Medicare rebate.
Saline infusion sonography: Medicare rebate available. Particularly useful for assessing submucosal fibroids and guiding surgical planning.
Uterine artery embolisation: Medicare rebate available for the procedure. Access varies by location, as it requires an interventional radiologist with specific expertise. Available at most major metropolitan centres but may require travel from regional areas.
MBS Online, 2025
Australian prevalence data
There is limited population-level prevalence data specific to Australian women. Most prevalence estimates are extrapolated from international studies (primarily US data), which may not accurately reflect the Australian population. The Baird et al. study (2003), which found cumulative incidence of over 80% in Black women and nearly 70% in White women by age 50, was conducted in the US.
Data on fibroid prevalence in Aboriginal and Torres Strait Islander women, and in Australia’s diverse multicultural population, is particularly lacking. This represents a significant research gap, as racial and ethnic differences in fibroid prevalence are well established internationally.
Baird et al., Am J Obstet Gynecol, 2003, PMID 12548202
Racial disparities - international evidence
International data consistently shows that women of African descent have a 2-3 times higher prevalence of fibroids, develop them at younger ages, have larger and more numerous fibroids, and experience more severe symptoms. These disparities likely reflect a combination of genetic factors, vitamin D levels, environmental exposures, and systemic inequities in healthcare access.
Whether these patterns hold in the Australian context, and how they interact with Australia’s unique multicultural population, is unknown. Dedicated Australian epidemiological research is needed.
Baird et al., Am J Obstet Gynecol, 2003, PMID 12548202; Eltoukhi et al., Adv Prev Med, 2014
Support organisations
National women's health organisation with evidence-based fibroid information. Provides consumer resources, translated materials, and a free health line (1800 JEAN HAILES). Their website includes detailed information on fibroid treatment options.
The Royal Australian and New Zealand College of Obstetricians and Gynaecologists provides patient information sheets on fibroids and treatment options. Their guidelines also inform clinical practice across Australia.
Australian Government-funded health information service with fibroid resources. Available 24/7 for health advice and can assist with finding local specialists and services.
herjourney.com.au · Health education, not medical advice
Evidence: Cochrane, PubMed, RANZCOG, FIGO · 2009-2026 · © Her Journey 2026