Non-invasive prenatal testing (NIPT) which was established as an additional pregnancy test for detecting of the common fetal trisomies 21 (T21), 18 (T18) and 13 (T13), is rapidly becoming a common clinical practice [1]. Save my name, email, and website in this browser for the next time I comment. False-negative trisomy 18 non-invasive prenatal test result due to 48,XXX,+18 placental mosaicism. Z score range from −3 to 3 was considered to indicate a low risk for a trisomy chromosome [14]. Press J to jump to the feed. Again, she brought up that we can get the CVS or wait for amnio. I am sooo very sorry for what you went through. Hey there, thank you for visiting the sub. Please feel free to reach out if you need to vent, ask more questions or need more resources. None of this is suprising because NIPT is a new technology that is continually evolving. Our results came back inconclusive unfortunately, so we had to redraw. Article  Doing amniocentesis is the only way to know for sure, BUT you don’t have to do it. Circulating cell-free fetal DNA in maternal serum appears to originate from cyto- and syncytio-trophoblastic cells. NIPT will give you a new risk (very low or very high) of having a baby with Down syndrome, trisomy 18, or trisomy 13. On the same day, I was able to see a sonologist for an ultrasound. Little chulzlette is a feisty one and she’s also celebrating this victory! Mardy A, Wapner RJ. On the same day, I was able to see a sonologist for an ultrasound. A study published earlier this year evaluated the concordance of NIPT and cytogenetic results among cases with positive or negative NIPT results., DOI: Required fields are marked *. Google Scholar. In their study, Shendure, Gammill and their colleagues looked at four women who’d received false positive results of a trisomy for chromosome 18. Even cvs can be incorrect. Article  ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Trisomy 18, NIPT: Received my test results today, everything measured good with baby but my bloodwork showed low levels of protein, so I'm positive for trisomy 18. CAS  Those are very likely normal babies! The amnio was done at 16 weeks and we were told we would get microarray and karyotype results in 10-14 days. Noninvasive prenatal diagnosis of common aneuploidies by semiconductor sequencing. PubMed  2011;342(jan11 1):c7401. Ledbetter DH, Zachary JM, Simpson JL, Golbus MS, Pergament E, Jackson L, Mahoney MJ, Desnick RJ, Schulman J, Copeland KL, et al. This has been emotionally and mentally hurtful. One of the topics on the agenda of those meetings were the causes of false positives following non-invasive prenatal testing (NIPT). As is commonplace, with time comes experience and the lens of scruitiny has recently been focused on the positive predicitive value (PPV) of NIPT. The often-heated debates on the hot topics, amongst which NIPT, were attended by over 400 colleagues. It’s important to remember that the NIPT is a screening test, not a diagnostic test. The remnants of placenta are still present and contribute to the NIPT signal. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Please read top 2 pinned posts & automod message for information about the screen and your result. doi: 10.1002/pd.4126. Springer Nature. 2013;33(6):609–11. At 33GA (Figure 1B), the patient was referred for further evaluation after a third trimester ultrasound revealed a 3.0 mm ventricular septal defect, and all four limbs were smaller than is observed at normal gestational weeks. Any variation in the genetic constitution compared to the normal can skew the results. Aihua Yin. However, false positive and false negative results still exist. CAS  doi: 10.1002/pd.4231. Hugs. Liao C, Yin A, Cf P, et al. NIPT has used for several years as part of prenatal care to screen high-risk patients for fetal aneuploidy, and it has been used increasingly in clinical practice. Canick JA, Palomaki GE, Kloza EM, et al. Discordant results between fetal karyotyping and non-invasive prenatal testing by maternal plasma sequencing in a case of uniparental disomy 21 due to trisomic rescue. Discordant noninvasive prenatal testing results in a patient subsequently diagnosed with metastatic disease. 2013;33(12):1207–10. This message is automatically generated for all submissions and might sometimes get it wrong. However, the appointment isn't until February 10th and I'm just feeling as if i cant even appreciate this pregnancy. Google Scholar. While some of us are lucky enough to find out the screen was wrong, others find out through diagnostic testing that the screening test was accurate. There are 2 main sticky posts about what NIPT is, how it works, what it can miss and how false positives happen, sono findings, and your chances of a true positive after NIPT. The non-invasive prenatal testing that evaluates circulating cell free DNA, and has been established as an additional pregnancy test for detecting the common fetal trisomies 21, 18 and 13 is rapidly revolutionizing prenatal screening as a result of its increased sensitivity and specificity. Google Scholar. NIPT is done to screen for fetal aneuploidies (extra copies of specific chromosomes) such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13). My story starts at the beginning of this year when my husband and I decided to seek help conceiving as we had been trying for 3yrs. Prenat Diagn. I’m 35 years old and 13w3d at the time of the scan. Due to... Ultrasound suggest a girl, NIPT predicts a boy?! Yearb Pathol Lab Med. For NIPT testing, it answers the question: "What is the probability that a positive result means that the fetus is affected?" Unfortunately, the CVS sample was too small to get results in two weeks so we were told we would get results in three weeks. 2016;16(8):759–66. We believe that this information will also influence the development of future diagnostic test methodologies. Combined GC-correction and Z-score testing methods were used to identify fetal autosomal aneuploidy for trisomy as described in Liao’s paper [13]. Indeed, we've written about it extensively on this blog. This page is updated regularly and provides the latest news and updates, including highlights from professional meetings, key research findings, society developments, and other information about noninvasive prenatal testing. b Ultrasound examination result at 33wk. The fetal DNA concentration was calculated as a quality control, as described in Yin’s paper [12]. © 2020 John Wiley & Sons, Inc., or related companies. Our report suggests that some pregnant women display regional placental mosaicism, which is sufficient to cause a discrepancy between the NIPT and karyotyping results. Saw a genetics counselor today and although she said that after inputting some numbers into her system and getting a result of 22% accuracy and 78% of it being a false positive she pushed and pushed for me to get a CVS today (as today would have been the last day to be able to get that as I turned 14 weeks). a Ultrasound examination result at 30wk. Clinical experience of non-invasive prenatal chromosomal Aneuploidy testing in 190,277 patient samples. Comment on “clinical application of massively parallel sequencing-based prenatal non-invasive fetal trisomy test for trisomies 21 and 18 in 11 105 pregnancies with mixed risk factors”. All authors have materially participated in the study and manuscript preparation. It is very important to stress that the PPV of any test is not intrinsic to the test. Why do false positive results occur during NIPT? The theoretical incidence of a vanishing twin with a chromosome abnormality is estimated to be around 0.11%. When adding ultrasound to NIPT, the new PPV for trisomy 18 was 100%, and the negative predictive value (NPV) was 92.3%, with a NPV of 85.7% in the first trimester and a NPV of 100% in the second trimester, respectively. doi: 10.1002/uog.13240. This information can not only contribute to the development of future screening test methodologies and algorithms, but can also help optimize the counseling and medical decision applied by medical practitioners. PubMed Central  They found that two of these women indeed had extra DNA on one of their own copies of the chromosome. PubMed Google Scholar. Confined placental mosaicism and its impact on confirmation of NIPT results. 2014;111(20):7415–20. However, this was consistent with the fetal umbilical cord blood karyotype results, which showed a T18 mosaicism ratio of 61%. Community for those with abnormal or discordant Noninvasive Prenatal Testing (NIPT/NIPS) screening results: FALSE POSITIVE, FALSE NEGATIVE, TRUE POSITIVE & those stuck in limbo. For example, even in high-risk populations with the relatively high prevalences of trisomy 21 (1:185), 18 (1:470) and 13 (1:1500), a NIPT test with 99.9% specificity (false-positive rate of 0.1%) would yield PPVs of 90% for trisomy 21, 67% for trisomy 18, and 53% for trisomy 13 .