I am so sad, i could not drive car or go to work because of over thinking about it. At my 20 blood work I tested positive … The accuracy of the test varies by disorder. What is the general accuracy of NIPT? Our NT measured at 6. One important cause of false positive results is confined placental mosaicism (CPM). Trisomy 21– More than 90% of Down syndrome cases are caused by trisomy 21. I have 2 big boys healthy. The screening has a detection rate of above 99 percent for the three most common chromosome abnormalities, trisomy 21, trisomy 18, and trisomy 13. : when 100 women have this test, one woman will be told there is an increased risk of Trisomy 21, whereas the baby does not have Trisomy 21. NIPT primarily looks for Down syndrome (trisomy 21, caused by an extra chromosome 21), trisomy 18 (caused by an extra chromosome 18), trisomy 13 (caused by an extra chromosome 13), and extra or missing copies of the X chromosome and Y chromosome (the sex chromosomes). This will be my third baby. NIPT positive for Trisomy 21 B The results from my cfDNA screening test gave a 61% positive predictive value for down’s, but the NT ultrasound was WNL at 2.4 (was told they flag over 3). Recieved the news on Monday that my NIPT had returned a 98% positive result for Trisomy 21 with a fetal fraction of 4%. In other words, out of 100 babies with Trisomy 21 the test will detect a minimum of 99 and miss a maximum of 1. An extra chromosome (chromosome 21) originates in the development of either the sperm or the egg. We are 12w4d and received a positive result for trisomy 18. I opted out of doing the new test at such an early stage in pregnancy. As discussed in the previous newsletter, all positive NIPTs should be confirmed by an invasive prenatal genetic test. A screening test suggested Sam had Trisomy 18, but he was born healthy. Today we went to the specialist for the NT and CVS. While NIPT is highly sensitive and specific, false positive results can occur. On average, in one percent NIPT gives a false positive, i.e. Importantly, the test manufacturers could immediately alter their analysis to rule out this particular type of false positive, said Dr. Hilary Gammill, a Fred Hutch and UW obstetrics researcher who ran the study along with UW geneticist Dr. Jay Shendure.. Those false positives are a big issue, Gammill said, because of the way the tests are marketed. We opted to have the CVS there and then for definitive results, but unfortunately the test had to be repeated the next day due to the Dr not collecting enough cells the first time and we are still anxiously waiting on the results. Non‐invasive prenatal testing (NIPT) has been widely used to screen for common aneuploidies since 2011. Test description. Lauren Owens/NECIR Dec. 14, 2014, 11:12 PM UTC / Updated Dec. 15, 2014, 12:55 AM UTC What's "funny" is that I was also offered MaterniT21 and I said yes, but they didn't have collection kits that day, so I returned the week after, at exactly 11w0d for the blood draw. One of the topics on the agenda of those meetings were the causes of false positives following non-invasive prenatal testing (NIPT). Invitae Non-invasive Prenatal Screening (NIPS) for Singleton Pregnancies analyzes whether a pregnancy is at increased risk for the chromosomal disorders listed below.All NIPS reports include analysis of chromosomes 21, 18, and 13 and assess the risk of the following trisomies: . ... NIPT positive for trisomy 18. t. tarasr. Test says risk after test is the infamous 1 in 17 for Trisomy 18/13. The false-positive rate is well under 1 percent. I am 35 years old, i just get result of NIPT positive 99.9% for 21 trisomy which mean down syndrom.