NIPT and next-generation sequencing

Next-generation sequencing reads many DNA fragments in parallel. For NIPT, a laboratory separates and analyses cell-free DNA in a maternal blood sample, including DNA released by the placenta, then uses the pattern of fragments to estimate the chance of selected chromosome differences. The method and panel depend on the laboratory and test ordered.

NIPT does not read a complete picture of fetal health. Placental DNA may not represent the fetus perfectly, and a screening result can be increased chance, decreased chance, or inconclusive. Only a diagnostic test can confirm a specific chromosome condition.

Before testing, ask which conditions and chromosome regions are included, how the sample is collected, and what happens if there is not enough usable DNA. Afterward, review the report with a qualified maternity or genetics professional. Continue ultrasound appointments; a nuchal translucency scan provides different information. An increased-chance report may lead to counselling and discussion of amniocentesis.

Contact your maternity team soon after an increased-chance or inconclusive report so follow-up can be planned without interpreting the result alone. Seek urgent pregnancy care for bleeding, severe pain, fluid loss, fainting, or later reduced fetal movements; sequencing cannot assess these symptoms.

Ask what the laboratory tested, how the result should be interpreted for your pregnancy, and whether an ultrasound finding changes the next step. Ask about diagnostic testing, including amniocentesis, and what support is available while you consider your options.