Fibroids are also known as leiomyomata. They are benign tumours of the myometrium and are very common, apparently in 1 in 25 women! Risk factors include a family history, Afro-Caribbean ethnicity and women approaching the menopause. Nulliparity/uniparity has been implicated as a risk factor, but many people are not sure whether this is a cause, or a result of pre-existing fibroids.
Their cause is unknown, however what is known is that they grow in response to oestrogens and progesterones. This causes several effects
- At menopause, when these hormone levels drop, Fibroids stop growing and often calcify.
- If HRT is used, the increasing hormone levels cause growth.
- Fibroid growth is cyclical.
Signs and Symptoms
50% of fibroids are asymptomatic, the remaining display symptoms depending on their type/position.
1 = Submucosal fibroid
4 = Subserosal polyp
5 = Intramural fibroid
Submucosal fibroids and intracavity polyps can give menorrhagia
. The polypoid fibroids can twist on their peduncle and cause torsion
. This presents as acute abdominal pain
, and needs prompt treatment to avoid necrosis and sepsis. Another complication that gives sepsis is ‘degeneration’
of the fibroid due to a decreased blood supply. This gives pain, bleeding and sepsis
. As the fibroids grow larger, they start to cause symptoms due to mass effect
. These are commonly, dysuria
Fibroids are a cause of Subfertility
, and should a pregnancy
occur, they are troublesome. They are a common cause of preterm labour
, and also malpresentations
of labour and PPH
. Because of the large bleeding risk you should never try to remove a fibroid at caesarean section.
On examination there may be a pelvic/abdominal mass on palpation. If there is degeneration or torsion the area will be tender too.
A very small proportion of fibroids are malignant. (0.1%)
Many fibroids are incidental findings. If they are being looked for, then an ultrasound
will show a uterine mass, however a MRI
, laparoscopic investigation
will be needed to show what type they are. Bloods
can let you know hormone levels; however haemoglobin levels are not reliable as a measure of anaemia
. Active bleeding causes a decreased Hb, but if the fibroid secretes erythropoietin then the Hb will be raised.
If the fibroid is small and asymptomatic then it can be left untreated
. First line treatment is often Tranexamic acid, NSAIDS or progesterones as they are used in menorrhagia. However they are ineffective if the bleeding is caused by fibroids, and other treatments should be used. GnRH
(gonadotrophin releasing hormone) agonists
are useful as they induce a menopause like state, in which the fibroid stops growing and may shrink, however these can only be used for 6 months
due to their side effects (similar to the menopause, osteoporosis
, increased CVS risks etc). After they are stopped then the fibroids continue to grow as before.
Surgery is normally required
- Hysteroscopic surgery can be used for submucosal or polypoid fibroids, usually preceded by GnRH agonists to decrease their size before surgery.
- Myomectomy – procedure in which the uterus is saved, often used for those who wish to conceive in the future, however there is an increased bleeding risk which may lead to hysterectomies, and all future deliveries have to be caesarean sections
- Hysterectomy – Can be done vaginally, abdominally or laprascopically.
- Uterine artery embolism – new treatment with an 80% success rate! The success rate is based on the fibroids shrinking by 50%<. There is however an increased readmission rate, and because it is a new treatment, the effects on future fertility are not yet clear.