Trisomy Screening in Pregnancy: Understanding Your Options (Including NIPT)
Updated: Apr 10
Prenatal Screening: Taking Time to Understand Your Options
At some point in early pregnancy, you may be offered screening tests to assess the likelihood of certain genetic conditions.
For some women, this feels like a straightforward decision. For others, it brings questions — not just about the tests themselves, but about what the results might mean.
There’s no single “right” choice here. My role is simply to ensure you have clear, balanced information so you can make a decision that feels right for you.
There’s no single “right” choice here.
What is prenatal screening?
Screening tests don’t give a diagnosis. Instead, they estimate the likelihood of your baby having certain conditions.
Depending on the result, you may be offered further diagnostic testing — but whether you take that step is always your choice.
What is offered on the NHS?
Within the NHS, you are usually offered one of two screening options:
Combined screening (first trimester)
Quadruple screening (second trimester, if first trimester screening is missed)
Combined screening detects around 80–85% of pregnancies affected by certain chromosomal conditions, particularly Down syndrome.
These tests are available at no cost and are part of standard antenatal care.
What is NIPT (Non-Invasive Prenatal Testing)?
NIPT is a more advanced screening test that analyses small fragments of your baby’s DNA circulating in your blood. It is performed through a simple blood test and can be done from around 10 weeks of pregnancy.
My personal preference is to perform the test after 11 weeks of pregnancy as there is more likely to be the right amount of fetal DNA needed for the test in your blood stream at this point. Not having enough present can lead to the test needing to be repeated.
Ultimately it is your decision though and if you would rather be tested earlier you can be.
NIPT is significantly more accurate than standard screening, with detection rates of:
Over 99% for Down's syndrome (Trisomy 21)
Around 95–99% for Edwards’ syndrome (Trisomy 18)
Around 90–95% for Patau’s syndrome (Trisomy 13)
Because of this, it has a much lower false-positive rate compared to NHS screening.
If you choose this option, I’m able to come to your home to take the blood sample. The cost of this appointment is typically around £450.
NIPT has a much lower false-positive rate compared to NHS screening.
What conditions does NIPT screen for?
NIPT screens for three main chromosomal conditions:
Down's syndrome (Trisomy 21) This occurs when there is an extra copy of chromosome 21. Children with Down syndrome usually have some level of learning disability and may have associated health conditions, though the range of ability and health varies widely, from mild implications, to children with severe health concerns.
It is important to note that no test can tell you how mildly or severely your child would be affected.
Edwards’ syndrome (Trisomy 18) A more serious condition caused by an extra copy of chromosome 18. It is associated with significant physical and medical complications, and sadly, many affected babies do not survive beyond infancy.
Patau’s syndrome (Trisomy 13) A rare condition caused by an extra copy of chromosome 13. It is linked with severe developmental challenges, and survival beyond the first year of life is uncommon.
What happens if a result comes back high-risk?
It’s important to remember that NIPT is still a screening test, not a diagnostic one. If a result suggests a higher likelihood of a condition, you would be offered further diagnostic testing (such as CVS or amniocentesis) to confirm.
At every stage, you remain in control of what you choose to do next.
A decision that’s about more than information
For some, this decision is primarily about gathering information. For others, it connects more deeply with personal values, beliefs, or how they feel about uncertainty.
You may already know what feels right for you. Or you may need time to think it through. Both are completely valid.
And if your faith is part of how you make decisions, this can also be something you bring into that process — seeking peace, wisdom, and clarity as you consider your options.
Taking this at your own pace
This isn’t something you need to decide immediately.
At your booking appointment, we’ll talk it through gently, and I can point you towards further reading if you’d like to explore things in more depth (see the links below).
If you’d like to discuss it further, or arrange testing, you’re always very welcome to reach out.
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