Uterine fibroids are benign (non-cancerous) growths that can be found in or around the uterus and are very common. 50-80% of women have them – and they can range in size from very small to very large. Some fibroids can even be big enough to change the shape and size of the uterus.
Many women with fibroids fall pregnant easily and have uncomplicated full-term pregnancies – often not even knowing they have a fibroid until it is detected on a routine pregnancy ultrasound. But for a small percentage of women, fibroids can be a lot more troublesome as they can interfere with conception, pregnancy and birth.
What causes fibroids?
The exact cause of fibroids is unknown, but it is believed that they are related to the levels of oestrogen and progesterone – the hormones produced in a woman’s ovaries. This explains why sometimes fibroids get bigger during pregnancy – when these hormones are at their peak – and then shrink again once a woman has given birth.
There are three types of fibroids:
- Intramural: Positioned in the wall of the uterus (most common)
- Submucosal: Positioned in the lining of the uterus
- Subserosal: Positioned on the outside of the uterus
What are the symptoms of fibroids?
Many women don’t even know they have a fibroid and are symptom – free. Other women, usually women with larger fibroids, can suffer from any of the following symptoms:
- Periods that are heavy, painful or go on for a long time
- Pain during intercourse
- Pressure in the back, bladder or bowel
- Frequent urination or difficulty urinating
How can fibroids affect fertility and pregnancy?
Depending on where it is growing, it is possible for a fibroid to prevent or interfere with conception. In some cases a fibroid may stop a fertilised egg from implanting properly in the uterus. This is can result in an early miscarriage.
Women who successfully fall pregnant, despite having a fibroid, are more at risk of developing complications later in their pregnancy or during birth. Some of these complications include:
- Bleeding : If the blood supply to the fibroid is obstructed during pregnancy, bleeding and pelvic pain can occur. Medical intervention is usually unnecessary as the bleeding tends to stop on its own.
- Miscarriage: If blood flow to the placenta is reduced, a miscarriage can occur.
- Odd position of baby: A very large or oddly shaped fibroid can force the baby into an awkward position, and a c-section delivery might be required.
- Early delivery: Sometimes if the fibroid is very large, it will compete with the baby for space inside the uterus. This can result in an early delivery.
- Obstructed labour: Fibroids that are near the cervix or those that grow into the birth canal can prevent a natural delivery and may result in a c-section.
- Postpartum haemorrhage: A very large fibroid may increase the risk of abnormal blood loss during delivery.
How are fibroids treated?
Problematic fibroids are not usually treated during pregnancy, unless a serious health concern emerges eg excessive bleeding or chronic pain. Fibroids that are not causing uncomfortable or painful symptoms are usually left alone and monitored.
Your doctor will discuss treatment options available. These may include:
- Medication: Some fibroids can shrink in size following a course of hormones or other drugs.
- Arterial embolisation: A small tube is inserted into the artery that supplies blood to the fibroid. This is done via a connected artery in either the leg or arm. Tiny particles are injected into the fibroid’s artery which stops the blood supply to the fibroid. Over time the fibroid dies and then shrivels away completely.
- Hysteroscopy: A process that removes the fibroid using a hysteroscope (a device that looks like a small telescope) through the vagina.
- Laparoscopy (keyhole surgery): A small tube is inserted through the stomach to remove the fibroid.
- Surgery: Very large fibroids that cannot be removed via a hysteroscopy or a laparoscopy may need to be removed through a cut in the stomach.
- Hysterectomy: In very rare cases, such as uncontrollable bleeding, a hysterectomy will need to be performed. This involves removing all or part of the uterus.