Cervical screening

Published by Bupa's Health Information Team, June 2011.

This factsheet is for women who are having cervical screening, or who would like information about it.

Cervical screening is a test to check the health of the neck of the womb (cervix). The test checks for changes in the cells of the cervix that may, if untreated, develop into cervical cancer. Catching any changes early can help to prevent cervical cancer.

About cervical screening

Cervical screening is sometimes called a smear test. It's a test used to examine the cells in your cervix for any changes. Cervical screening isn't a test for cancer, but it can pick up changes to cells in your cervix that could, if left untreated, become cancer in the future.

During a cervical screening test, a small sample of cells is taken from an area on the surface of your cervix called the transformation zone. These cells are then checked for any changes in a laboratory, using a microscope.

The NHS runs a cervical screening programme in the UK. In England and Northern Ireland, women between 25 and 64 years old are invited for screening. In Scotland, women between 20 and 60 are included in the programme, and in Wales, women between 20 and 64 are screened.

You will be invited by your GP surgery to have cervical screening at least once every three years. As you get older, this may change to once every five years. Your GP or your practice nurse will do the test at your GP surgery. You can also have cervical screening at a community clinic, such as a family planning, sexual health or well woman clinic.

You need to be registered with a GP to receive an invitation to screening.

Cervical smear testing is also available at independent facilities, including Bupa Wellness centres.

Deciding on cervical screening

It's your choice whether or not to have a smear test for cervical screening. To make an informed decision and give your consent, it's important that you're aware of the benefits and risks of cervical screening.

Benefits

Cervical screening can help to pick up changes in the cells of your cervix that could lead to cervical cancer in the future. Cervical screening can help to prevent around 75 out of every 100 cervical cancers from developing.

Cervical screening is the best way to detect the changes that lead to cervical cancer. Almost half of the women who develop cervical cancer in the UK have never had a cervical screening test.

Risks

It's important to remember that, although cervical screening is the best way of checking the health of your cervix, it isn't a perfect test.

Cervical screening may not always detect abnormal cells. This is because the cells sometimes look very similar to normal cells, or there may be very few abnormal cells. It's also possible for the person doing your test to miss abnormal cells, no matter how experienced they are. At least two people now check every screening test so this is highly unlikely. The test is now also carried out using a procedure called liquid-based cytology, which helps to preserve the cells and make the results much more reliable.

Sometimes, screening can show possible signs of cervical cancer when in fact there is no problem. This is called a false positive result. If this happens, you will be asked to have further tests, which can cause unnecessary worry. You may be diagnosed as having mild cell changes, which never would have progressed to cancer or caused you any problems. If this happens, it's possible you may receive unnecessary treatment.

Preparing for cervical screening

If you have your period then it can be difficult for your nurse or GP to see your cervix well enough to get a good sample. This means you may need to come back and be tested again. Make your appointment for cervical screening so that it falls in between your periods.

Don't have sex using a spermicide, lubricating jelly or a barrier method of contraception, such as a condom, for 24 hours before the test. The chemicals in these products can affect the test.

What happens during cervical screening

A cervical screening test usually takes just a few minutes. You will be asked to undress from the waist down and lie on your back on a couch, with your legs drawn up and knees apart. If this position is difficult for you to get into, your nurse or GP can take the test with you lying on your side.

You may find the test uncomfortable but it isn't usually painful. The test is more likely to be painful if you're tense. Try to relax and breathe slowly and deeply.

Your GP or nurse will use an instrument called a speculum to gently open your vagina, so that he or she can see your cervix.

The cell sample is taken from your cervix using a small brush, which is then placed in liquid. This procedure is called liquid-based cytology. The sample will be sent to a laboratory for testing.

If you're pregnant, and have had normal screening tests previously, your GP is likely to postpone any routine screening until three months after your baby is born. If you have had an abnormal test and then become pregnant, your GP or midwife may offer you a test at your first antenatal appointment.

What to expect afterwards

You may have some light bleeding after the test. If you have heavy bleeding or pain after your test, talk to your GP.

Getting your results

The results of your test should automatically be sent to the surgery or clinic where you had the test done. Ask the person taking your test to tell you when your results will be ready. If your result is negative, then you may not be contacted, but you should be contacted if there is anything wrong. To make sure you get your results, contact your GP or clinic.

Changes to cells in the cervix are called cervical intraepithelial neoplasia or CIN for short. There are different grades of CIN according to how severe the changes in your cells are, from CIN1 (minor change) to CIN3 (severe change). These grades relate to how far the abnormal cells have gone into the surface layer of your cervix.

Around nine out of 10 tests are normal. About five in 100 tests show borderline or mild cell changes (CIN1). If you have mild cell changes, these usually go back to normal by themselves. You will be asked to come back for cervical screenings every six months until the cells return to normal. If the cells don't go back to normal, you may need to have treatment.

One in 100 tests shows moderate cell changes (CIN2) and one in 200 shows severe changes (CIN3). If you have moderate or severe changes to the cells of your cervix, you will be asked to have further investigations, such as a colposcopy. You may also need treatment to remove the cells.

Sometimes the result may be 'inadequate' or 'unsatisfactory' because the sample was not good enough or the cells could not be seen clearly, for example, because of an infection. This happens in about one in every four tests. If this happens, you will need to have another test. If you have an infection, you may need to get it treated first.

If you have any queries about cervical screening, ask your GP or your practice nurse.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.