Non-invasive Prenatal Testing (NIPT)
How does NIPT work?
NIPT uses a special genetic technology that measures fetal DNA of chromosomes 21 and 18 circulating in the mother’s blood. From this information, the chances of Down syndrome (trisomy 21) and trisomy 18 are determined. Our partnering NIPT labs, Integrated Genetics and Ariosa, provide the analysis called Harmony™. It is a novel, highly multiplexed assay termed “digital analysis of selected regions” (DANSR™).
What conditions can NIPT detect?
NIPT can detect pregnancies affected by two chromosome problems, Down syndrome and trisomy 18. While they are each caused by the presence of an extra chromosome, they have distinct features. Down syndrome causes mild to moderate problems in development; trisomy 18 tends to be more severe.
What does a negative result mean?
A negative result means that the chance of a chromosome problem is quite low. Almost all pregnancies that are unaffected by these chromosome problems will screen negatively.
What does a positive result mean?
A positive result means that the chance of a chromosome problem is increased. 99% of pregnancies with Down syndrome and 98% of pregnancies with trisomy 18 will be flagged as a positive screen. A positive result does not mean that a pregnancy is actually affected. Only definitive testing with CVS or amniocentesis can determine the true presence of a chromosome problem.
What are the next steps after NIPT?
NIPT is a very targeted screen, determining the likelihood of only two conditions. NIPT does not replace standard methods of screening including ultrasound evaluation at 18-20 weeks.