scholarly journals New screen on the block: non-invasive prenatal testing for fetal chromosomal abnormalities

2017 ◽  
Vol 9 (4) ◽  
pp. 248 ◽  
Author(s):  
Sara Filoche ◽  
Beverley Lawton ◽  
Angela Beard ◽  
Anthony Dowell ◽  
Peter Stone
Keyword(s):  
False Positive ◽  
Chromosomal Abnormalities ◽  
False Positive Rate ◽  
Prenatal Testing ◽  
Diagnostic Procedures ◽  
First Trimester ◽  
Maternal Blood ◽  
Non Invasive ◽  
Positive Rate ◽  
Trimester Screening

ABSTRACT Non-invasive prenatal testing (NIPT) is a new screen for fetal chromosomal abnormalities. It is a screening test based on technology that involves the analysis of feto-placental DNA that is present in maternal blood. This DNA is then analysed for abnormalities of specific chromosomes (eg 13, 18, 21, X, Y). NIPT has a much higher screening capability for chromosomal abnormalities than current combined first trimester screening, with ~99% sensitivity for trisomy 21 (Down syndrome) and at least a 10-fold higher positive predictive value. The low false-positive rate (1–3%) is one of the most advertised advantages of NIPT. In practice, this could lead to a significant reduction in the number of false-positive tests and the need for invasive diagnostic procedures. NIPT is now suitable for singleton and twin pregnancies and can be performed from ~10 weeks in a pregnancy. NIPT is not currently publicly funded in most countries. However, the increasing availability of NIPT commercially will likely lead to an increase in demand for this as a screening option. Given the high numbers of women who visit a general practitioner (GP) in their first trimester, GPs are well-placed to also offer NIPT as a screening option. A GP’s role in facilitating access to this service will likely be crucial in ensuring equity in access to this technology, and it is important to ensure that they are well supported to do so.

Reducing false positive rate of fetal monosomy X in non‐invasive prenatal testing using a combined algorithm to detect maternal mosaic monosomy X

2019 ◽  
Vol 39 (4) ◽  
pp. 324-327 ◽  
Author(s):  
Minh‐Duy Phan ◽  
Binh T. Vo ◽  
Thong V. Nguyen ◽  
Nhat‐Thang Tran ◽  
Huong N.T. Trinh ◽  
...  
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
Prenatal Testing ◽  
Non Invasive ◽  
Monosomy X ◽  
Positive Rate ◽  
Combined Algorithm

scholarly journals Ductus Venosus: A Love Story of 14 Years

2011 ◽  
Vol 5 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Nuno Montenegro ◽  
Alexandra Matias
Keyword(s):  
Blood Flow ◽  
Chromosomal Abnormalities ◽  
False Positive Rate ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Ductus Venosus ◽  
Love Story ◽  
Positive Rate ◽  
Trimester Screening ◽  
Twin Pregnancies

ABSTRACT Ductus venosus is a tiny vessel with a central role in fetal circulation. Combining B-mode with color and pulsed Doppler is feasible to identify this vessel and evaluate the blood flow waveform at 11 to 13 weeks. The higher prevalence of abnormal A-wave in fetuses with abnormal karyotype and/or cardiac defects turned DV evaluation into a useful marker for chromosomal abnormalities and cardiopathies. Even when combined with nuchal translucency (NT) or biochemical markers, DV blood flow evaluation contributes to an increase in sensitivity and reduces false-positive rate. Abnormal ductal flow is also related to a worse fetal and perinatal outcome. In monochorionic twin pregnancies, in addition to NT measurement at 11 to 14 weeks, the Doppler assessment of DV blood flow increases relevantly the performance of screening for those at higher risk of developing twin-to-twin transfusion syndrome. This story of 14 years surely contributed to change the way first trimester screening is being implemented.

scholarly journals Ductus venosus pulsatility index measurement reduces the false-positive rate in first-trimester screening

2010 ◽  
Vol 36 (6) ◽  
pp. 661-667 ◽  
Author(s):  
E. Timmerman ◽  
K. Oude Rengerink ◽  
E. Pajkrt ◽  
B. C. Opmeer ◽  
J. A. M. van der Post ◽  
...  
Keyword(s):  
False Positive ◽  
Pulsatility Index ◽  
False Positive Rate ◽  
First Trimester ◽  
Ductus Venosus ◽  
First Trimester Screening ◽  
Index Measurement ◽  
Positive Rate ◽  
Trimester Screening

scholarly journals Antenatal screening for aneuploidy

2017 ◽  
Vol 7 (1) ◽  
pp. 234 ◽  
Author(s):  
Smita S. Patne ◽  
Aditi J. Upadhye ◽  
Shantanu C. Shembekar ◽  
Chaitanya A. Shembekar ◽  
Jayshree J. Upadhye
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
False Positive ◽  
False Positive Rate ◽  
First Trimester ◽  
Second Trimester ◽  
Marker Test ◽  
Second Trimester Screening ◽  
Positive Rate ◽  
Trimester Screening

Background: It is uncertain how best to screen pregnant women for the presence of fetal Down's syndrome and other aneuploides, whether to perform first-trimester screening or to perform second-trimester screening or both.Methods: Women with singleton and multiple pregnancies underwent first-trimester combined screening (measurement of nuchal translucency, pregnancy-associated plasma protein A [PAPP-A], and the free beta subunit of human chorionic gonadotropin at 10 weeks 3 days through 13 weeks 6 days of gestation). Also, second-trimester quadruple screening (measurement of alpha-fetoprotein, total human chorionic gonadotropin, unconjugated estriol, and inhibin A) and triple marker test was done from 15 to 18 weeks of gestation.Results: 12 (5%) patients had positive screening test for combined screening in first trimester, 6 (10.9%) patients had positive screening for quadruple test while 1 (2.85%) patients had positive screening for triple test. Out of 19 positive screening, 16 (84.21%) had their amniocentesis done for confirmation of diagnosis. In all 16 patients, chromosomal analysis was normal. Not a single patient turned out to have a baby with Down syndrome or any other aneuploidy. False positive rate for combined screening in first trimester was 5%, false positive rate for quadruple test in second trimester was 10.9%, false positive rate for triple marker test in second trimester was 2.85%.Conclusions: First-trimester combined screening is better than second-trimester quadruple test or triple marker test for syndrome or any other aneuploidy.

scholarly journals Assessment of a change of protocol of prenatal screening by inclusion of non-invasive prenatal diagnosis

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Rocío Cabra-Rodríguez ◽  
Guadalupe Bueno Rodríguez ◽  
Cristina Santos Rosa ◽  
Miguel Ángel Castaño López ◽  
Sonia Delgado Muñoz ◽  
...  
Keyword(s):  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
Screening Program ◽  
High Sensitivity ◽  
Maternal Blood ◽  
Screening Tests ◽  
Loss To Follow Up ◽  
Non Invasive ◽  
Second Trimester Screening ◽  
Trimester Screening

AbstractObjectivesNon-invasive prenatal screening (NIPS) is a test for the detection of major fetal chromosomal abnormalities in maternal blood during pregnancy. The purpose of this study was to assess the performance of NIPS implemented within the framework of the Screening Program for Congenital Abnormalities of the Andalusian Health System.MethodsA retrospective observational study was undertaken to determine the number of NIPS tests performed since its introduction. The number of invasive diagnostic tests done after the implementation of NIPS in the patients included in the program between March 2016 and August 2017 was also quantified.ResultsA total of 6,258 combined first- and second trimester screening tests were performed, covering 95% of the population. In total, 250 subjects were identified as high risk, of whom 200 underwent NIPS after loss to follow-up. NIPS showed a sensitivity of 100% (95% CI: 76.84–100%) and a specificity of 99.46% (95% CI: 97.04–99.99%).ConclusionsThis test has proven to have a very high sensitivity and specificity. The results obtained demonstrate that the incorporation of NIPS in clinical practice minimizes the rate of miscarriages and reduces the frequency of invasive procedures by 70%.

scholarly journals Low False-Positive Rate of Aneuploidy Detection Using Fetal Cells Isolated from Maternal Blood

1998 ◽  
Vol 13 (6) ◽  
pp. 380-380 ◽  
Author(s):  
Felix de la Cruz ◽  
Harvey Shifrin ◽  
Sherman Elias ◽  
Diana W. Bianchi ◽  
Laird Jackson ◽  
...  
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
Maternal Blood ◽  
Fetal Cells ◽  
Positive Rate

Impact of Including or Removing Nuchal Translucency Measurement on the Detection and False-Positive Rates of First-Trimester Down Syndrome Screening

2015 ◽  
Vol 40 (3) ◽  
pp. 214-218 ◽  
Author(s):  
Emmanuel Spaggiari ◽  
Isabelle Czerkiewicz ◽  
Corinne Sault ◽  
Sophie Dreux ◽  
Armelle Galland ◽  
...  
Keyword(s):  
Down Syndrome ◽  
False Positive ◽  
False Positive Rate ◽  
Method Comparison ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Routine Practice ◽  
Detection Rates ◽  
Significant Difference ◽  
Positive Rate

Introduction: First-trimester Down syndrome (DS) screening combining maternal age, serum markers (pregnancy-associated plasma protein-A and beta-human chorionic gonadotropin) and nuchal translucency (NT) gives an 85% detection rate for a 5% false-positive rate. These results largely depend on quality assessment of biochemical markers and of NT. In routine practice, despite an ultrasound quality control organization, NT images can be considered inadequate. The aim of the study was to evaluate the consequences for risk calculation when NT measurement is not taken into account. Material and Method: Comparison of detection and false-positive rates of first-trimester DS screening (PerkinElmer, Turku, Finland), with and without NT, based on a retrospective study of 117,126 patients including 274 trisomy 21-affected fetuses. NT was measured by more than 3,000 certified sonographers. Results: There was no significant difference in detection rates between the two strategies including or excluding NT measurement (86.7 vs. 81.8%). However, there was a significant difference in the false-positive rates (2.23 vs. 9.97%, p < 0.001). Discussion: Sonographers should be aware that removing NT from combined first-trimester screening would result in a 5-fold increase in false-positive rate to maintain the expected detection rates. This should be an incentive for maintaining quality in NT measurement.

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