Why screening tests are done in pregnancy
During your pregnancy you'll be offered some routine tests known as screening tests.
Screening tests are done to find out if you or your baby are at risk of having certain health problems. If any possible risks are identified, more detailed tests called diagnostic tests can then be done to identify if any medical treatment is needed.
Many screening tests are offered to all pregnant women - other tests are only offered to women who are at high risk of a particular health problem.
Screening tests are usually free. If you need an NIPT (Harmony test or Panorama) test, you might need to pay for it.
Differences between screening tests and diagnostic tests
Screening tests are usually 'non-invasive' - the tests are done on the outside of your body. There's no risk of them causing a miscarriage. Screening tests include tests like ultrasound scans and blood tests.
Diagnostic tests may be more invasive or more expensive than screening tests. In pregnancy, diagnostic tests include amniocentesis and CVS (chronic villus sampling).