Fibroids are common non-cancerous growth of the muscle tissue that makes up the uterus. They arise from a single smooth muscle cell and are responsive to the hormones oestrogen and progesterone. Fibroids are present in up to 70% of women by age 50 though the percentage of women affected by symptoms is much lower.
Early onset of periods, increasing age, polycystic ovarian syndrome, being above a normal weight and increased consumption of red meat and alcohol may increase the risk of fibroids. Some women also have a genetic predisposition to forming fibroids. Use of long acting progesterone-based contraceptives and having one or more pregnancies reduces the risk.
Many women with fibroids are asymptomatic though they can cause heavy periods, pelvic pain and pelvic pressure. Rarely, fibroids are associated with infertility and specific pregnancy complications.
The presentation of fibroids is dependent on their size, location and the age of the woman affected. Fibroids can be located within the cavity of the uterus (submucosal), in its wall (intramural) or on the outside of the cavity (subserosal). Occasionally fibroids are located in the cervix (the neck of the uterus). `
Where fibroids are suspected the diagnosis is usually made on pelvic ultrasound. Occasionally where further information is required an MRI scan will be performed. Fibroids may also be incidentally recognised during other procedures such as laparoscopy (key hole abdominal surgery), caesarean sections and hysteroscopies (a camera guided curette that visualises the inside of the uterus).
Treatment for fibroids is only required where patients are symptomatic or very occasionally where they are believed to be affecting fertility. The choice of treatment and its approach also depends on the size and location of the fibroid.
Treatment options range from medical to radiological and surgical. They include:
- Hormonal:
- Combined contraceptives
- Intrauterine devices containing progesterone (Mirena ®)
- Progesterone receptor modulators (Ulipristal acetate)
- Hormonal suppression (Zoladex ®)
- Radiological
- Uterine artery embolization- X ray guidance is used to block some of the blood vessels supplying the uterus
- Non-invasive MRI guided ablation of fibroids with ultrasound (MRgFUS)
- Surgical
- Myomectomy (removal of fibroid). This can be done via the abdomen (laparoscopic or open surgery) for intramural and subserosal fibroids or via the cervix (hysteroscopic) for sub-mucosal fibroids.
- Hysterectomy (removal of the entire uterus). Suitable only for women who have completed their family and after careful consideration. This procedure will permanently prevent fibroids from recurring.
Fibroids and infertility
Submucosal fibroids and some intramural fibroids (that distort the cavity of the uterus) can be associated with reduced fertility and an increased miscarriage rate. These fibroids only account for 2% of cases of infertility and should only be treated where other causes have been excluded. Where it is felt removal of a fibroid distorting the cavity of the uterus would be beneficial this is usually performed hysteroscopically.
Fibroids and pregnancy
Occasionally fibroids can cause issues during pregnancy, labour and delivery.
Complications include:
- Miscarriage
- Preterm delivery
- Abnormal presentation of the baby (not head first)
- Placental abruption (placental separation from the uterine wall prior to delivery)
- Caesarean section
- Heavy bleeding after delivery
- Pain in pregnancy.
Treatment prior to pregnancy depends on the number of fibroids, their size and location. Often no treatment is required. Once pregnant management involves careful surveillance and planning for delivery to reduce the risk of complications. Removal of fibroids during pregnancy and delivery is potentially dangerous and is usually avoided.
