Fibroids are benign (non-cancerous) tumours that grow in or around the womb (uterus). The growths are made up of muscle and fibrous tissue and can vary in size from the size of a pea to the size of a football in extreme cases. They may occur singly or there may be multiple fibroids present.

Fibroids usually develop during a woman’s reproductive years (from approximately 16 to 50 years of age). They are linked to the production of oestrogen which is the female reproductive hormone. Fibroids can grow anywhere in the womb. The main five types of fibroids are described below:

• Intramural fibroids develop in the muscle wall of the womb and they are the most common types of fibroids found in women.
• Sub-serosal fibroids grow outside the wall of the womb into the pelvis and become very large.
• Sub-mucosal fibroids develop in the muscle beneath the inner lining of the womb wall and they grow into the middle of the womb.
• Pedunculated fibroids grow from the outside wall of the womb and are attached to the womb wall by a narrow stalk.
• Cervical fibroids develop in the wall of the cervix (the neck of the womb).

Are Fibroids Common?

How Common Are Fibroids
Fibroids are common with at least 1:4 women developing them at some stage in their life. They occur most often in women who are from 30 to 50 years old. Fibroids tend to develop more frequently in woman who are of Afro Caribbean origin and in woman who are over weight. It is thought they occur in heavier women as a result of higher oestrogen levels.

In many cases fibroids do not cause symptoms and treatment is not required.  After the menopause when oestrogen levels decline, fibroids will often shrink and disappear without any treatment.  However sometimes fibroids can cause symptoms such as pain or heavy bleeding.  Intramural and sub-mucosal fibroids are known to impair implantation of embryos and in such cases treatment may be required.  Treatment may either be medical or surgical.  The choice of treatment is dependant on many factors including the age of the patient, size and site of the fibroids and whether or not the patient wishes to become pregnant in the future.


Medical Treatment
Gonadotrophin releasing hormone agonist (GnRHa) GnRHa is a hormone that is often recommended to treat fibroids.  It is given by injection and works by making the body release only small amounts of oestrogen.  This causes the fibroids to shrink.  GnRHa stops your menstrual cycle (period) but it is not a form of contraception.  GnRHa can be given as a nasal spray or a monthly or three monthly injection.  GnRHa may cause a number of menopausal type side effects including:

  • Hot flushes
  • Increased sweating
  • Muscle stiffness
  • Vaginal dryness
  • Tiredness
  • Mood swings

Long term treatment may be associated with osteoporosis (thinning of the bone) and sometimes additional medicine in (HRT) is given to minimise the risk of this if treatment is given long term.  When treatment stops fibroids often start to grow again.

Other Medicines

Tranexamic acid
These tablets work by helping the blood in your womb to clot thereby reducing the amount of bleeding.  These tablets only need to be taken during episodes of bleeding.

Anti-inflammatory Drugs
Anti-inflammatory medicines such as Ibuprofen, Mefenamic acid and Diclofenac are taken for a few days during the menstrual period and may ease heavy bleeding and also pain caused by uterine cramps.  They work by reducing the body’s production of a hormone like substance called Prostaglandin which is linked to heavy periods.

The Contraceptive Pill
The contraceptive pill is a popular form of contraception that stops an egg from being released from the ovaries to prevent pregnancy.  As well as making periods lighter some contraceptive pills will also reduce period pain.

Levonorgestrel Intrauterine system (Mirena IUS)
The Mirena intrauterine system is a small plastic device that is placed in the womb and releases the progesterone hormone called levonorgestrel.  This prevents the lining of the womb from thickening during the menstrual cycle and therefore bleeding at the end of each month is much lighter or in some cases absent altogether.


Surgical Treatment for Fibroids
The type of surgery used to treat fibroids depends on the size and site of the fibroids and whether or not the woman wishes to retain her option for having children in the future.

Surgical Treatment Explanation
Hysteroscopic myomectomy This procedure involves placing an instrument through the cervix into the uterine cavity and cutting away the fibroid under direct vision with a wire loop.  This is performed under general anaesthesia normally as a day case and patients can return to normal activity within a few days.
Myomectomy Myomectomy is a surgical procedure to remove fibroids that are sub-serosal or intramural.  This is particularly suitable for patients who wish to retain their fertility.  Myomectomy can either be performed laparoscopically (keyhole) or as an open procedure.  This depends on individual circumstances such as the size, site and number of the fibroids.
Hysterectomy Hysterectomy is a surgical procedure to remove the womb.  This may be recommended if the fibroids are very large.  This is the best way of preventing fibroids re-occurring.  Hysterectomy may be performed in a variety of ways including vaginal, laparoscopic (keyhole) or laparotomy (open surgery).