NIPT, often called a fetal DNA test, analyses placental cell-free DNA in maternal blood to estimate the chance of selected chromosome conditions. Reports commonly use terms such as “low risk” and “high risk”. These describe a screening estimate, not a diagnosis.

What does a low-risk result mean?

A low-risk result means that the estimated chance of the conditions listed in the report—often trisomy 21, trisomy 18 and trisomy 13—has decreased after screening. It does not reduce the chance to zero. Conditions outside the panel, structural birth differences and some chromosome changes cannot be excluded by this result.

Routine prenatal follow-up and recommended ultrasound examinations should therefore continue. If ultrasound findings or a strong family history raise concern, further assessment may be appropriate even after a low-risk result.

What does a high-risk result mean?

A high-risk result indicates an increased chance of the chromosome condition tested; it does not confirm that the fetus is affected. The probability that a high-risk result is a true positive depends on the condition, the patient’s prior chance, gestational age and biological factors such as confined placental mosaicism. It is therefore not identical for every patient or chromosome.

The next step is usually a review of the full report, detailed ultrasound and genetic counselling. Diagnostic confirmation may be offered through CVS or amniocentesis, depending on gestational age.

What does a no-result report mean?

A result may not be issued because of a low fetal fraction, sample-related technical limitations or biological factors. This is neither a normal nor an abnormal result by itself. Repeat blood sampling is not automatically the best option for everyone; the clinician should consider gestational age, ultrasound findings and whether diagnostic testing is more appropriate.

Questions to ask during the result review

• Which chromosomes and conditions were included in the panel?
• How should the reported risk be interpreted alongside my prior chance?
• Was the fetal fraction adequate and are technical limitations stated?
• Is diagnostic confirmation recommended, and by which method?
• Are further ultrasound examinations or other tests needed?

Irreversible pregnancy decisions should not be made on the basis of an NIPT screening result alone. High-risk findings should be evaluated with diagnostic testing and unbiased genetic counselling.

Review your fetal DNA result with a specialist

For the scope of screening and the next steps, explore our NIPT service. For a high-risk, uncertain or no-result report, learn more about our genetic counselling service.