Description
Combined Test (Nuchal Translucency) – No Longer Available
Innermost Healthcare no longer offers the Combined Test as a private screening test.
The Combined Test is a first-trimester screening test that combines:
- an ultrasound measurement of the nuchal translucency (NT), the fluid-filled space at the back of the baby’s neck
- the mother’s age
- two maternal blood markers, PAPP-A and free β-hCG
These are combined to calculate the chance of the baby having:
- Down’s syndrome (trisomy 21)
- Edwards’ syndrome (trisomy 18)
- Patau’s syndrome (trisomy 13)
The Combined Test remains part of NHS antenatal screening pathways. However, for women choosing private screening, we now recommend Non-Invasive Prenatal Testing (NIPT) because it provides substantially more accurate screening for these three chromosome conditions and has a much lower false-positive rate.
Why do we recommend NIPT instead?
NIPT analyses small fragments of cell-free DNA from the pregnancy that circulate in the mother’s blood.
Compared with the Combined Test, NIPT provides:
- a higher detection rate for Down’s syndrome
- improved screening performance for Edwards’ and Patau’s syndromes
- a substantially lower false-positive rate
- screening from a simple maternal blood sample
NIPT is still a screening test, not a diagnostic test. A high-chance NIPT result does not confirm that the baby has the condition.
If NIPT indicates a high chance of a chromosome condition, we would normally recommend discussion with an appropriately experienced clinician and consideration of diagnostic testing by chorionic villus sampling (CVS) or amniocentesis before making irreversible decisions about the pregnancy.
Is the nuchal translucency measurement still important?
Yes.
Although NIPT is more accurate than the Combined Test for screening for trisomy 21, 18 and 13, ultrasound assessment in the first trimester remains important.
An increased nuchal translucency can be associated with:
- chromosome conditions
- congenital heart conditions
- structural abnormalities
- some genetic syndromes and single-gene conditions
- an increased chance of pregnancy complications
Some of these conditions will not be detected by routine NIPT.
For this reason, NIPT should not be viewed as a replacement for good-quality first-trimester ultrasound assessment.
Where the nuchal translucency is significantly increased or an ultrasound abnormality is identified, we may recommend a more detailed discussion about diagnostic testing rather than relying on NIPT alone.
What screening should I choose?
If you are looking for private screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome, we recommend reviewing our range of Non-Invasive Prenatal Testing (NIPT) options.
Different NIPT tests are available depending on whether you would like screening limited to the common trisomies or more extensive screening.
If you are unsure which test is most appropriate, our clinical team can discuss the available options with you.
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