NIPT or NT scan? Why the 2026 evidence supports doing Both

Article produced in association with London Pregnancy Clinic

One of the most common questions in early pregnancy: NIPT or the nuchal translucency (NT) scan – do I really need both? The 2026 evidence gives a clear answer.

The two tests look at different things, and doing them together is how first-trimester screening works at its best.

This is not a debate between old and new technology. NIPT is a genuine advance in detecting chromosome abnormalities from a maternal blood sample.

The NT scan is the first detailed look at how the fetus is forming. What each sees, the other largely cannot.

What NIPT actually tells you

NIPT – non-invasive prenatal testing – analyses fragments of fetal DNA circulating in the mother’s blood. Taken from around 10 weeks, the test measures chromosome proportions to flag the common trisomies: trisomy 21 (Down syndrome), trisomy 18 (Edwards) and trisomy 13 (Patau).

Most panels include fetal sex and sex-chromosome aneuploidies. Extended NIPT adds selected microdeletion syndromes – most commonly 22q11.2 (DiGeorge syndrome) – and the newest whole-genome platforms can detect copy-number variants down to around 1 Mb across every chromosome.

What NIPT does not look at is anatomy. It tells you whether the chromosomes are numerically correct.

It cannot tell you how the heart, brain, spine, kidneys or abdominal wall are forming, because it analyses DNA, not structure.

The NHS offers NIPT as a second-line screening test, reserved for women who receive a higher-chance result from the combined test – precisely because NIPT is best understood as one part of a wider screening picture rather than the whole of it.

What the NT scan actually tells you

The NT scan is an ultrasound performed at 11 to 14 weeks that measures the nuchal translucency – a small fluid-filled space at the back of the fetal neck.

Protocols developed by the Fetal Medicine Foundation, the group that pioneered first-trimester screening under Professor Kypros Nicolaides at King’s College Hospital, combine the NT measurement with additional markers: nasal bone, ductus venosus flow, tricuspid regurgitation, and maternal serum biomarkers (PAPP-A and free β-hCG).

More importantly, the scan is the first structural assessment of the fetus.

Major anomalies already visible at 11-14 weeks include absence of the cranial vault, large body-wall defects such as omphalocele and gastroschisis, megacystis, severe cardiac defects with abnormal four-chamber views, and skeletal dysplasias.

An increased NT measurement itself – even with a completely normal chromosome result – is associated with a notable rate of structural heart defects and monogenic syndromes that NIPT cannot detect.

Why the combination outperforms either test alone

Taken together, NIPT and the NT scan give complementary coverage.

For the common trisomies, NIPT is more sensitive than the NT scan alone. Pooled data place detection of trisomy 21 above 99 per cent with a false-positive rate around 0.1 per cent.

Combined first-trimester screening without NIPT, using NT and serum markers alone, reaches approximately 90 per cent detection – and up to 95 per cent when nasal bone, ductus venosus and tricuspid flow are added – at a 3 to 5 per cent false-positive rate.

For that specific endpoint, NIPT is the more accurate test.

The NT scan picks up almost everything NIPT misses: structural anomalies, early markers of monogenic syndromes, confirmation of viability, accurate dating, twin chorionicity, and placental position.

An increased NT with a normal NIPT result shifts the clinical conversation toward syndromes like Noonan, Kabuki and the skeletal dysplasias – conditions with single-gene origins rather than chromosomal ones.

Working out which is which often requires genetic testing beyond NIPT. Carrier screening and expanded genetic panels – including those offered at Jeen Health – cover the single-gene territory that NIPT does not address.

When the combination matters most

Several patient groups have most to gain from doing both:

• Women conceiving after IVF or with donor gametes, where maternal age and fertility treatment each subtly shift risk profiles
• Women aged 35 and over, where baseline chromosomal risk is higher and soft markers are more likely
• Anyone with a previous pregnancy affected by an anomaly or loss, where reassurance matters
• Twin pregnancies, where NIPT performance depends on fetal fraction and structural assessment is more complex
• Women who have had a raised or borderline result on earlier screening markers

Chromosomes and anatomy are two separate clinical questions. Each needs its own answer.

What happens if the tests disagree

Disagreements between NIPT and the NT scan are not failures of either test – they are the reason both are done.

• NIPT low-risk, NT raised: consider monogenic syndromes, structural cardiac assessment, and early anomaly ultrasound follow-up
• NIPT higher-chance, scan normal: confirmatory diagnostic testing (CVS or amniocentesis) before any major decision
• NIPT no-call: repeat sampling, gestational age check and clinical review – a no-call itself is associated with an increased chromosomal risk
• Both abnormal: a clear indication for specialist fetal medicine review and early diagnostic testing

Professional guidance from the RCOG supports this complementary approach, emphasising that NIPT is a screening rather than a diagnostic test, and that its results are most useful when interpreted alongside ultrasound findings.

Practical guidance for 2026

The most efficient way to run both tests is in a single appointment window, between 10 and 14 weeks, with the blood sample taken first and the scan performed on the same visit.

Results typically return within 5 to 10 working days for standard NIPT panels, and same-day for the scan itself.

This is the logic behind the SMART Test at London Pregnancy Clinic – extended NIPT paired with a full first-trimester ultrasound in a single appointment, delivering both chromosomal and structural information in one visit. For most patients, it removes the false choice of picking one over the other.

The wider picture

The question of NIPT versus NT scan has a settled clinical answer in 2026: the two tests examine different aspects of the pregnancy, and the most complete first-trimester assessment uses both.

For a pregnancy a woman wants to carry with the fullest possible picture, both tests belong in the first-trimester window. The question worth asking is which clinic offers them together, with the pre- and post-test care that makes the results usable.

If you are deciding on first-trimester screening, a consultation with a fetal medicine specialist is the most useful first step.

Disclaimer: This article is produced for informational purposes only and does not constitute medical advice, diagnosis or treatment. Clinical guidance referenced reflects published NHS, Fetal Medicine Foundation and RCOG standards as at April 2026. Individual circumstances vary; readers are advised to consult a qualified healthcare professional before acting on any information in this article. This piece was produced in association with London Pregnancy Clinic, which provided background clinical information for editorial purposes. Hyperlinks to external sources are included for reference only and do not represent an endorsement of any product, service or organisation.