When is the test carried out?

The chorionic villus sampling test can be carried out earlier than the amniocentesis test so it may be recommended for couples with a high risk. Usually the test is carried out between 10 and 13 weeks. It is not advisable to have the test before this time because there is a higher risk of miscarriage.

The CVS test is not recommended for all pregnant women; usually only women with a high risk of having a baby with an inherited condition will be advised to have the test. Possible risk factors include:

• Age: women over the age of 35 will usually be advised to have this test, as the chances of having a baby with Down’s syndrome increase as you get older.
• Family history: if you have a history of an inherited condition, such as cystic fibrosis or muscular dystrophy, you may be advised to have the test as the risks are higher.
• If you have had problems during a previous pregnancy; for example, if you have had a baby with an inherited condition.
• If you have had previous tests, such as blood tests or ultrasound scans, which have flagged up possible problems.

What happens after the test is finished?

After the test you will be advised to rest for a period of 24 hours; during this time you may experience pains which are similar to menstrual pains and you may experience some spotting (this is light bleeding).

You should seek medical advice if you experience any of the following symptoms:

• Excessive bleeding
• Vaginal discharge
• A high temperature (over 38 degrees)