Why diagnostic tests are carried out in pregnancy

Diagnostic tests are sometimes done during pregnancy to check for chromosomal and genetic conditions in unborn babies.

These can include:

  • Down syndrome
  • Edwards’ syndrome
  • Patau’s syndrome

You may be recommended for a diagnostic test if:

  • your screening test or ultrasound scan suggest that your baby may have one of these conditions
  • you have previously had a baby with a serious medical or genetic condition
  • you are very worried about the risk of chromosomal or genetic conditions

Making an informed choice

Diagnostic tests are often the only way to be sure if your baby has certain health problems.

They can:

  • reassure you that your baby has no abnormalities
  • give you time to prepare for a baby with special needs
  • help you decide if you want to continue with your pregnancy

However diagnostic tests can:

  • never be 100% accurate
  • be invasive
  • increase the risk of miscarriage
  • increase anxiety - especially if you feel you would continue with your pregnancy regardless of the results

Ask your obstetrician or midwife to explain the risks involved in diagnostic tests.

Page last reviewed: 17 May 2019
Next review due: 17 May 2022

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