Fibroids are also known as leiomyomas. These are benign smooth muscle tumours of the uterus with a capsule around the tumours.
They are very common. About 50% of women will develop fibroids. Fibroids become smaller after menopause. The exact cause is not known. Fibroids are more common when there is a family history of fibroids, and may be more common among those who are obese.
Fibroids may not affect women symptomatically and may only be discovered during a routine ultrasound scan or routine pelvic examination during screening. Symptoms may be attributed to the fibroids if they are present in the cavity of the uterus (womb) or if they are large. These symptoms may include heavy regular menses which may result in iron deficiency anaemia, and occasionally may cause pain during periods. If large, there could be pressure on the bladder causing frequent urination, and on the bowel causing constipation or diarrhea.
Fibroids are generally classified according to their positions in the uterus:
intramural fibroids (wholly in the uterine muscle)
subserosal fibroids (present on the surface of the uterus)
submucosal fibroids (distorts the surface of the uterine cavity)
Women with fibroids tend to have slightly increased risks of infertility and slightly increased risks of complications during pregnancy including miscarriage, degeneration of the fibroid causing pain during pregnancy, preterm labour and intrauterine growth restriction. In general, surgery to remove these fibroids have not been shown to reduce the risks of miscarriage, preterm labour and intrauterine growth restriction during pregnancy. Submucosal fibroids should be removed though as they tend to cause difficulty in getting pregnant or increased risk of miscarriages.
Treatment options include:
1. Expectant monitoring
Most fibroids do not need any treatment. They may be monitored every 3-12 monthly by ultrasound scan if they are not large and not causing any symptoms.
These may be accomplished via open laparatomy approaches or minimally invasive laparoscopic (abdominally) or hysteroscopic (via the cervical opening of the uterus) approaches
a) Myomectomy - removal of the fibroids only.
b) Hysterectomy - removal of the whole uterus.
3. Medications - these medications include:
a) GnRH agonist injections - these injections cause transient menopausal state to reduce the fibroids. They are effective in reducing the size of the fibroids for a few months, but the fibroids typically grow again after the effect of the medication has worn out after a few months. Therefore they are only useful when the women are near menopause, or just before surgery to shrink the fibroids to allow a different approach to the surgery.
b) Ulipristal acetate (marketed as Esmya) - these oral medications have been used for women to shrink the fibroids before surgery to allow a different approach to the surgery, or as an intermittent treatment for women in whom surgery is not suitable. It is highly effective in reducing the heavy menses. The effectiveness to shrink the fibroid, however, is highly variable. They should be avoided in women who have liver problems as liver failure has been reported in a few cases. There is limited data on the outcomes of pregnancies that have resulted after treatment with Esmya.
4. Uterine artery embolization
This is a minimally invasive procedure which uses fluoroscopy (or real-time X-ray) to guide the delivery of agents into the arteries into the uterus to block these arteries, and cause the fibroids to shrink from the resulting dramatic reduction in blood supply to these fibroids. Similarly, there is limited data on the outcomes of pregnancies that have resulted after treatment with uterine artery embolization.
5. High intensity focused ultrasound (HIFU)
It is a non-invasive treatment option which uses MRI-guided focused high intensity ultrasound waves to ablate the fibroids. Whilst non-invasive, there is still risks of injury to surrounding bowel (intestines), bladder and vessels, like the risks during surgery, as these organs are near the area of interest. There is also limited data on the outcomes of pregnancies that have resulted after treatment with HIFU.