The pathophysiology of uterine fibroids (also called leiomyoma, fibroma, fibromyoma, myoma or leiomyofibroma) is not well understood. There is, however, some epidemiological evidence to suggest a genetic predisposition for non-syndromic uterine fibroids, although no specific gene has yet been identified.

Oestrogen and progesterone are recognized as promoters of tumor growth, and the potential role of environmental oestrogens has only recently been explored. Growth factors with mitogenic activity, such as TGF-β3, bFGF, EGF, and IGF-I, are elevated in fibroids and may be the effectors of oestrogen and progesterone promotion¹².

Several predisposing factors have been identified as being associated with uterine fibroids, including black race, heredity, nulliparity (the condition of never having given birth), obesity, polycystic ovary syndrome (PCOS), diabetes, and hypertension, and there is emerging evidence that familial predisposition to uterine fibroids is associated with a distinct pattern of clinical and molecular features compared with uterine fibroids in families without this prevalence¹³.

While many patients with mild/moderate symptoms can be managed using various pharmacological treatments, previously patients presenting with moderate/severe symptoms would progress to a point where surgical or radiological interventions would have been required. The main driver for the decision to undertake fibroid surgery is due to the severity of symptoms including uterine bleeding, discomfort, and pain. The size of the uterus and fibroids affects the decision to perform surgery, and which type of surgery is chosen.

Surgical interventions include hysterectomy, or in women who wish to preserve their fertility, the more conservative option is myomectomy.

While myomectomy is a preferable option for women who desire to preserve fertility, it has a higher risk of post-operative pyrexia (fever), pelvic haematoma formation and post-operative adhesions, and may need to be repeated if fibroids reappear. Other less invasive procedures which have been developed include Uterine Artery Embolisation (UAE), and, in women where the dominant symptom is bleeding, fibroid size is relatively small, and fertility is not an issue, endometrial ablation.

Surgery for treatment of uterine fibroids is rarely performed as an emergency procedure, and waiting several months before proceeding to surgery is the standard in European countries for many patients.

An array of various therapies is available to manage uterine fibroids. These fall into two main categories⁴⁶: pharmacological therapies and surgical treatments.

This procedure involves a small, lighted telescope called a hysteroscope being placed into the cervix through the uterus. Saline solution is injection into the uterus expanding the uterine cavity and allowing the investigation of the uterus.

Sonohysterography is used to evaluate the extent of submucosal fibroid tumours, but is a relatively invasive procedure².

Magnetic resonance imaging (MRI) is the preferred choice when precise fibroid mapping is required e.g. size and location of fibroids. This type of diagnostic method is usually used for surgical purposes.

While there is no clear consensus and limited literature regarding predisposing risk factors for development of uterine fibroids, risk of uterine fibroids has been associated with such factors as age, ethnicity, family history, reproductive factors, lifestyle and medical conditions, and use of exogenous sex steroids¹⁰.

Women are most likely to be diagnosed with fibroids during their forties; however, it is not clear whether this is due to an increased formation or increased fibroid growth secondary to hormonal changes during this time¹⁰.

Fibroids are more common in Black women than Caucasian women, and in fact are estimated to be 2-3 times higher in women of African descent compared to European descent, however the incidence reported may be due to health access, method of diagnosis or verification of self-reported diagnosis^20,21.

Although no specific gene has been identified as the cause of non-syndromic fibroids, there is convincing evidence of the role of heredity as a risk factor for uterine fibroids ²². Furthermore, it appears that fibroids with familial prevalence behave differently from those that occur sporadically in families, lending weight to the argument that fibroids are not a uniform pathological condition¹³.

Several studies have shown that reproductive factors including age at menarche, parity, pregnancy, interval since last term pregnancy and levels of endogenous hormones are associated with uterine fibroids^13, 23-30.

Lifestyle and medical conditions, including non-smoker status, a diet rich in red meat and obesity have all been linked with an elevated risk of uterine fibroids ^{10, 13, 23, 31-36}.

The true prevalence of uterine fibroids is often underestimated, as women who do not come into contact with healthcare professionals are not captured in the incidence statistics. However it is known that incidence increases with age ⁸.

Uterine fibroids are the most common benign tumours in women of reproductive age with a clinically relevant prevalence in 20-40% of women during their reproductive years², although they are rare in teenagers. They are more common in Black women than Caucasian women, and in fact are estimated to be 2-3 times higher in women of African descent compared to European descent¹⁸.

Around 25% of these women will have symptoms that impact activities of daily life or require treatment¹⁹.

Figure illustrating Prevalence of uterine fibroids⁹

Figure illustrating Prevalence of uterine fibroids⁹