Edwards Syndrome Screening: Complete Guide
Screening for Edwards syndrome is offered to every pregnant woman in the UK as a routine, optional part of antenatal care. It doesn't diagnose the condition — it estimates the chance of it being present, giving you information to decide what, if anything, you want to do next.
What Edwards syndrome is
Edwards syndrome, also known as Trisomy 18, happens when a baby has an extra copy of chromosome 18 in their cells instead of the usual two. This extra genetic material affects development significantly, and sadly most pregnancies affected by Edwards syndrome end in miscarriage or stillbirth, with babies who are born often having a very short life expectancy due to complex health problems. It is a rare condition, and screening exists so that parents can be given accurate information and appropriate support as early as possible, whatever they decide to do with that information.
How screening works
- The combined test, usually carried out between 11 and 14 weeks, looks at your age, a blood sample, and the nuchal translucency measurement taken during your dating scan to calculate a chance score.
- Non-invasive prenatal testing (NIPT), sometimes offered on the NHS after a higher-chance combined test result, or available privately, analyses small fragments of the baby's DNA in your blood and is more accurate at identifying higher chance pregnancies.
- If either test comes back as "higher chance," you'll be offered a conversation with a specialist midwife or doctor to talk through your options, which may include a diagnostic test such as chorionic villus sampling (CVS) or amniocentesis.
- Diagnostic tests carry a small risk of miscarriage, so whether to have one is entirely your choice, and no one will pressure you into a decision either way.
Understanding your result
A "lower chance" result means Edwards syndrome is unlikely but cannot be completely ruled out by screening alone. A "higher chance" result means the calculated probability crosses a set threshold — it is not a diagnosis, and many babies given a higher chance score turn out not to have the condition. If you receive a higher chance result, a specialist midwife will talk you through what it means and what your options are, without any obligation to proceed further.
Making your own decision
Screening is always optional, and you can decline it at any point in your pregnancy without needing to give a reason. Some parents want as much information as possible as early as possible; others prefer not to know unless there's a clear medical reason to act on it. Both are entirely valid choices, and your midwife is there to support whichever path you take.
Frequently Asked Questions
How common is Edwards syndrome?
Edwards syndrome is rare, and the vast majority of pregnancies are not affected by it. Screening exists precisely because it's uncommon enough that most people won't need diagnostic testing, but rare enough that the NHS offers routine screening so families can access support and information if it is present.
What happens if my baby has Edwards syndrome?
If a diagnostic test confirms Edwards syndrome, you'll be offered detailed counselling from a specialist team to discuss what this means for your pregnancy and the choices available to you, including continuing the pregnancy with specialist support or ending it. There is no right answer, and the decision is entirely yours, made with full medical information and support.
Can I decline Edwards syndrome screening?
Yes, completely. Screening for Edwards syndrome, along with Down's and Patau's syndrome, is offered as part of routine antenatal care but is never mandatory. You can decline all or part of it, and your care will continue exactly the same either way.
This article is for informational purposes only and does not constitute medical advice.
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