Irregular Periods

Irregular or infrequent periods (oligomenorrhoea)
Reviewed by Dr Philip Owen, consultant obstetrician and gynaecologist

It's common for periods to be light and widely spaced when you first start having periods.

Periods also become more irregular as you get older and near the menopause.

This is normal because you won't produce an egg every month as you start and end fertility.


What if it isn't down to puberty or menopause?

Many women experience widely spaced periods, typically having one or two periods every six months. This may concern you, but it is very unlikely that there is a serious underlying cause.

If you are worried about the frequency of your periods, you should see your GP.


What else can cause irregular periods?

The commonest cause of infrequent periods is a condition called polycystic ovaries (PCOS).

Women with PCOS have a large number of very small (less than 1cm) cysts on their ovaries and a hormone imbalance. The cysts interfere with regular ovulation and so periods are infrequent.

PCOS is a common condition that affects as many as 10 per cent of women.


How is a diagnosis made?

The diagnosis of polycystic ovaries is made on the basis of one or more blood tests to measure hormone levels, often with a pelvic ultrasound scan of the ovaries.


What about treatment?

Treatment is only necessary if:

* you are concerned about the irregularity of your periods
* you are having difficulty becoming pregnant.


Based on a text by Dr Erik Fangel Poulsen, specialist
Last updated 16.02.2005