Non-invasive prenatal test (NIPT)

Many couples would like to follow the development of their child as early as possible. As part of prenatal care, it is possible to have a screening test for trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) and trisomy 13 (Pätau syndrome). Trisomies are chromosomal disorders (the corresponding chromosome is present three times instead of twice). In most cases, they are not hereditary, but arise spontaneously and more frequently at an older maternal age (from about 35 years) and can be detected early in pregnancy.

What is the non-invasive prenatal test?

NIPT is a screening procedure that provides evidence for the presence of the most common chromosomal disorders (trisomy 21, 18 and 13) in the unborn child. NIPT uses cell-free fetal DNA derived from exfoliated cells of the placenta that circulates in maternal blood. We use Illumina's CE-certified VeriSeq NIPT Solution v2 testing procedure. This is based on whole-genome next-generation sequencing (NGS).

What can be determined with the NIPT?

In addition to the trisomies mentioned above, if desired, a determination of the child's sex or an examination for anomalies of the sex chromosomes (Turner, triple X, Klinefelter, XYY syndrome) can also be performed.

When can NIPT be performed?

The test can be performed from the 11th week of pregnancy (10+0 p.m.).

What does the NIPT cost?

Since 01.07.2022, the costs for the examination for trisomies 21, 18 and 13 are covered by the German health insurances in justified cases; the additional examinations are self-pay services.

How safe is the NIPT?

The sensitivities (detection rates) for trisomy 21, 18 and 13 are about 90-100%, for the maldistribution of sex chromosomes about 90-92%. The false positive rate is 0.1%. Possible causes of false-positive results include placental amosaics (approximately 2% of pregnancies), "vanishing twin," chromosomal abnormalities, and maternal malignancies.An abnormal result in the NIPT should always be verified by invasive diagnostics.

What are the limitations of the method?

It is useful to combine NIPT with early malformation ultrasound at 12-13 weeks of gestation to detect developmental abnormalities and malformations not detected by NIPT as early as possible. NIPT cannot replace conventional chromosomal analysis, and an unremarkable NIPT does not rule out fetal malformations.