What is endometriosis?

In endometriosis, the same kind of cells that line the uterus (endometrial cells) grow in other parts of the body, usually in the pelvis.

These endometrial cells grow then shrink, grow then shrink, at the same time as your menstrual cycle. Sometimes they die off and form scar tissue.

Some women can have endometriosis and not know it. But for others, these extra cells can cause:

• tummy or pelvic pain
• painful, heavy or irregular periods
• pain with passing wind, urine or stools
• pain during sex
• constipation
• diarrhoea
• weeing more often

How does endometriosis affect fertility?

Many women with endometriosis fall pregnant naturally. But about a third of women with endometriosis have trouble getting pregnant.

In women with severe endometriosis, that is probably because the abnormal cells, or scar tissue caused by the abnormal cells may:

• block the ovary releasing eggs
• block the tubes
• stop the tubes working properly

But it’s not so clear for women with mild endometriosis. The main theory is that the endometrial cells cause inflammation, and this inflammation interferes with the delicate balance of hormones that women need to become pregnant.

Learn more about the female reproductive system.

How does endometriosis affect pregnancy and my baby?

Most women with endometriosis will have a normal pregnancy. Extra monitoring is not recommended, but this is something to discuss with your doctor.

Your midwife or doctor will watch out for high blood pressure. There is a slightly higher than average risk that you will get some bleeding towards the end of your pregnancy.

There is also a chance your baby will be born earlier than usual or smaller than usual.

Read more about staying healthy while you are pregnant.

During pregnancy, endometriosis can improve but it often comes back later and may cause problems becoming pregnant again.

What causes endometriosis?

Nobody really knows.

Every woman who has periods has the same sort of menstrual cycle. The lining of the uterus breaks down and flows out the vagina.

But some of the menstrual fluid might flow back up the fallopian tubes and into the abdomen. That might happen in most women.

In many women, that menstrual fluid sitting in the abdomen is reabsorbed without any worries. But it seems that some women don’t reabsorb the menstrual fluid. It sits there, and turns into endometriosis.

It is not clear why this happens for some women and not others. But it can run in families.

Can I prevent endometriosis?

Endometriosis can't be prevented, but staying as healthy as you can might help with symptoms. For example, exercise, relaxation and ensuring you have enough sleep can help you manage pain.

Endometriosis can usually be treated with medications or surgery. See healthdirect for more information.

Endometriosis tends to get better with menopause, when you stop having periods.

Where to get help

If you suffer with period pain that affects your usual activities, or you have other symptoms that worry you, visit your doctor. For further information about endometriosis, see healthdirect or visit the Jean Hailes website.