scholarly journals Prenatal Screening of Aneuploidies

2021 ◽  
Author(s):  
Madhavilatha Routhu ◽  
Shiva Surya Varalakshmi Koneru
Keyword(s):  
Down Syndrome ◽  
Trisomy 21 ◽  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
First Trimester ◽  
Maternal Plasma ◽  
Structural Defects ◽  
Screening Methods ◽  
Second Trimester ◽  
History Of

Chromosomal abnormalities includes1) abnormalities in number of chromosomes which are known as aneuploidies and 2) structural defects like translocations and deletions. In this we will discuss about Aneuploidies The incidence of Aneuploidy is around one in 200 live births. Aneuploidy increases with advancing maternal age. Fetal aneuploidy has been associated with significant pregnancy complications such as growth restriction, congenital malformations and perinatal deaths. Several Major developments are happened in prenatal screening of Aneuploidy especially the introduction of first trimester screen with Nuchal thickness and fetal cell free DNA in maternal plasma and identification of ultrasound markers and biochemical screening in second trimester. In this chapter we will discuss about what are trisomies, why “Down syndrome” is important to detect prenatally, history of “Down syndrome”, advances in screening methods biochemical as well as sonographic markers in first and second trimester and the criteria to get those markers. What are the features of trisomy 21, trisomy18 and trisomy13.

scholarly journals Sensitivity and specificity of prenatal screening methods for detection of risk of fetal chromosomal abnormalities

2020 ◽  
Vol 9 (2) ◽  
pp. 540
Author(s):  
Sunil Kumar Juneja ◽  
Pooja Tandon ◽  
Anjali Sharma ◽  
Anshu Sharma
Keyword(s):  
Early Detection ◽  
Sensitivity And Specificity ◽  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
First Trimester ◽  
Diagnostic Methods ◽  
Screening Methods ◽  
Second Trimester ◽  
Test Sensitivity ◽  
Pregnant Mothers

Background: Babies born with chromosomal abnormalities pose a burden on the family as well as the society at large. Early detection and management of fetal chromosomal abnormalities has become an essential component of antenatal care. Hence pregnant women of all ages are offered screening methods for early detection of chromosomal abnormalities. We intended to study the sensitivity and specificity of prenatal screening methods for detection of risk of fetal chromosomal abnormalities.Methods: A three-year retrospective study was conducted from January 2015 to December 2017 in 258 singleton pregnant mothers attending antenatal clinic and delivering at DMCH. The patients were screened for chromosomal abnormalities in the first trimester by NB NT scan along with dual marker and level II anomaly screen scan along with quadruple test in the second trimester. Based on the test results the patients were classified into high risk and low risk pregnant mothers. All the patients with abnormal quadruple test were subjected to amniocentesis for karyotyping. The results of the first trimester and second trimester screening methods were statistically analyzed using chi square test, sensitivity and specificity of the prenatal screening methods was calculated.Results: The sensitivity and specificity of dual marker test for detection of chromosomal abnormality is 50% and 85.94% respectively and that of quadruple test sensitivity is 50%, specificity is 95.3%. The difference was highly significant in the favour of the quadruple marker with P-value of 0.0004.Conclusions: While counseling the patients regarding possibility of having abnormal fetus, obstetrician should keep in mind the false negatives and false positives of prenatal screening and diagnostic methods.

scholarly journals The impact of prenatal screening tests on prenatal diagnosis in Taiwan from 2006 to 2019: a regional cohort study

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Ching Hua Hsiao ◽  
Ching Hsuan Chen ◽  
Po Jen Cheng ◽  
Steven W. Shaw ◽  
Woei Chyn Chu ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Prenatal Screening ◽  
Diagnostic Testing ◽  
First Trimester ◽  
Screening Tests ◽  
Screening Methods ◽  
Second Trimester ◽  
Invasive Procedures ◽  
Trimester Screening ◽  
The Impact

Abstract Background The purpose of this study is to evaluate the impact of prenatal screening tests on prenatal diagnosis in Taiwan’s 14 years from 2006 to 2019. Methods The prenatal screening methods evolved from the second-trimester serum screening to combined first-trimester screening (cFTS) and then followed by the non-invasive cell-free DNA prenatal test (NIPT). The data used by the Department of Statistics, the Ministry of Health and Welfare and Department of Household Registration, Ministry of the Interior public website. Results This regional registry-based cohort retrospective study examined a total of 2,775,792 births from January 2006 to December 2019. The proportion of advanced maternal age (AMA) pregnancies increased from 11.63% in 2006 to 30.94% in 2019. Overall, invasive diagnostic testing was used in 87.22% of AMA pregnancies. The prenatal detection rate of trisomy 21 and 18 increased from 74.1% and 83.3% in 2006 to 96.9% and 98.8% in 2019, respectively. Conclusion During the second-trimester and cFTS periods, the percentage of AMA pregnancies increased every year and the number of invasive procedures also accompany with increased percentage of AMA. However, during the period that NIPT were implemented, the percentage of invasive procedures decreased.

scholarly journals Prenatal Screening Markers for Down Syndrome: Sensitivity, Specificity, Positive and Negative Expected Value Method

2018 ◽  
Vol 37 (1) ◽  
pp. 62-66
Author(s):  
Jasmina Durković ◽  
Milan Ubavić ◽  
Milica Durković ◽  
Tibor Kis
Keyword(s):  
Down Syndrome ◽  
Biochemical Markers ◽  
Trisomy 21 ◽  
Prenatal Screening ◽  
Protein A ◽  
First Trimester ◽  
Expected Value ◽  
Maternal Serum ◽  
Beta Hcg ◽  
Sensitivity Specificity

SummaryBackground: Genetic screening for chromosomopathy is performed in the first trimester of pregnancy by determining fetal nuchal translucency (NT), and the pregnancy associated plasma protein-A (PAPP-A) and free human chorionic gonadotropin (free-beta HCG) biomarkers in maternal serum. Methods: We tested the sensitivity, specificity, positive and negative expected values of each marker with the aim of setting a model for prenatal screening readings. Statistical data treatment has been performed on a sample of 340 pregnant women with positive results of prenatal screening. Results: Sensitivity of PAPP-A was 0.6250 (probability 62.50%), free beta HCG 0.5893 (58.93%), NT 0.1785 (17.85%). Specificity of PAPP-A was 0.5106 (probability 51.06%), free beta HCG 0.5246 (52.46%), NT 0.9718 (97.18%). Positive expected value of PAPP-A was 0.2011 (probability 20.11%), free beta HCG 0.1964 (19.64%), NT 0.556 (55.56%). Negative expected value of PAPP-A was 0.8735 (probability 87.35%), free beta HCG 0.8662 (86.62%), NT 0.8571 (85.71%). The NT marker has a significantly higher specificity, which means that its normal value will significantly reduce the final risk of trisomy 21. The sensitivity of NT is much lower than that of biochemical markers, which means that a pathological value of NT does not have a significant influence on the final risk, i.e. the significantly higher sensitivity of biochemical markers will reduce the final risk of trisomy 21. Conclusion: The analyses stress the importance of using a software which has the possibility to separate the level of a biochemical risk by correlating PAPP-A and free beta HCG and, by adding the NT marker, calculate the level of a final risk of Down syndrome.

‘The Stuff of Slow Constitution’: Reading Down Syndrome for Race, Disability, and the Timing that Makes Them So

Somatechnics ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Mel Y. Chen
Keyword(s):  
Down Syndrome ◽  
Trisomy 21 ◽  
Historical Perspective ◽  
Early History ◽  
Present Moment ◽  
History Of ◽  
Living Being

In this paper I would like to bring into historical perspective the interrelation of several notions such as race and disability, which at the present moment seem to risk, especially in the fixing language of diversity, being institutionalised as orthogonal in nature to one another rather than co-constitutive. I bring these notions into historical clarity primarily through the early history of what is today known as Down Syndrome or Trisomy 21, but in 1866 was given the name ‘mongoloid idiocy’ by English physician John Langdon Down. In order to examine the complexity of these notions, I explore the idea of ‘slow’ populations in development, the idea of a material(ist) constitution of a living being, the ‘fit’ or aptness of environmental biochemistries broadly construed, and, finally, the germinal interarticulation of race and disability – an ensemble that continues to commutatively enflesh each of these notions in their turn.

Trends in early prenatal screening for chromosomal abnormalities and congenital malformations in Russia in 2018

2020 ◽  
pp. 76-78
Author(s):  
Е.А. Калашникова ◽  
Е.Н. Андреева ◽  
П.А. Голошубов ◽  
Н.О. Одегова ◽  
Е.В. Юдина ◽  
...  
Keyword(s):  
Reference Values ◽  
Congenital Malformations ◽  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
First Trimester ◽  
First Trimester Screening ◽  
Trimester Screening ◽  
Overall Effectiveness ◽  
Regions Of Russia

В ходе анализа результатов раннего пренатального скрининга (РПС) в России за 2018 г. (Аудит-2019) дана оценка качества мероприятий, общей эффективности и тенденций развития системы РПС в субъектах РФ посредством сравнения рассчитанных основных организационных, методологических и интегральных показателей с международными референтными значениями. In the course of analyzing the results of early prenatal combined first-trimester screening (FTS) in Russia for 2018 (Audit-2019) the assessment of the quality of measures, the overall effectiveness and trends in the development of the FTS system in the regions of Russia. They are presented by comparing the calculated main organizational, methodological and integral indicators with international reference values.

The Natural History of Trisomy 21: Outcome Data from a Large Tertiary Referral Centre

2021 ◽  
pp. 1-7
Author(s):  
Clare O’Connor ◽  
Rebecca Moore ◽  
Peter McParland ◽  
Heather Hughes ◽  
Barbara Cathcart ◽  
...  
Keyword(s):  
Trisomy 21 ◽  
Pregnancy Loss ◽  
Loss Rate ◽  
Outcome Data ◽  
Second Trimester ◽  
Referral Centre ◽  
Tertiary Referral ◽  
Tertiary Referral Centre ◽  
History Of ◽  
Baseline Demographic

<b><i>Objective:</i></b> The aim of the study was to prospectively gather data on pregnancy outcomes of prenatally diagnosed trisomy 21 (T21) in a large tertiary referral centre. <b><i>Methods:</i></b> Data were gathered prospectively in a large tertiary referral centre over 5 years from 2013 to 2017 inclusively. Baseline demographic and pregnancy outcome data were recorded on an anonymized computerized database. <b><i>Results:</i></b> There were 1,836 congenital anomalies diagnosed in the study period including 8.9% (<i>n</i> = 165) cases of T21. 79% (<i>n</i> = 131) were age 35 or older at diagnosis. 79/113 (69.9%) women chose a termination of pregnancy (TOP) following a diagnosis of T21. Amongst pregnancies that continued, there were 4 second-trimester miscarriages (4/34, 11.7%), 9 stillbirths (9/34, 26.4%), and 1 neonatal death, giving an overall pregnancy and neonatal loss rate of 14/34 (41.1%). <b><i>Conclusion:</i></b> The risk of foetal loss in prenatally diagnosed T21 is high at 38% with an overall pregnancy loss rate of 41.1%. This information may be of benefit when counselling couples who are faced with a diagnosis of T21 particularly in the context of limited access to TOP.

Four Years' Experience With an Interlaboratory Comparison Program Involving First-Trimester Markers of Down Syndrome

2010 ◽  
Vol 134 (11) ◽  
pp. 1685-1691
Author(s):  
Glenn E. Palomaki ◽  
George J. Knight ◽  
Geralyn Lambert-Messerlian ◽  
Jacob A. Canick ◽  
James E. Haddow
Keyword(s):  
Down Syndrome ◽  
Chorionic Gonadotropin ◽  
Plasma Protein ◽  
Human Chorionic Gonadotropin ◽  
Interlaboratory Comparison ◽  
Protein A ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Second Trimester ◽  
Coefficients Of Variation

Abstract Context.—We initiated a voluntary, self-funded interlaboratory comparison program in the fall of 2005 because no proficiency testing program was available to laboratories in North America offering first-trimester, combined serum and ultrasound, Down syndrome screening. Objectives.—To evaluate the first 4 years of the interlaboratory comparison program against stated goals, to identify areas of concern, and to create new initiatives as indicated. Design.—Five serum samples are distributed 3 times a year to be tested for pregnancy-associated plasma protein A, human chorionic gonadotropin or its β subunit, and dimeric inhibin-A; participants convert these results into multiples of the median. Patient histories include nuchal translucency information that enables the calculation of the risk of Down syndrome. Also included are educational components linked to interlaboratory comparison program results. Assessment of integrated (first- and second-trimester markers) risks is accomplished by having participants combine interlaboratory comparison program results with their results from a second-trimester proficiency testing program administered by the College of American Pathologists. Results.—The precision profile for pregnancy-associated plasma protein A shows decreasing coefficients of variation with increasing pregnancy-associated plasma protein A concentrations and multiples of the median (25% to 11% and 30% to 15%, respectively). In contrast, coefficients of variation are a relatively constant 12% throughout the entire range of human chorionic gonadotropin results. On a logarithmic scale, the median coefficient of variation of the risk of Down syndrome is 9%. Conclusions.—Participants in the interlaboratory comparison program reliably measure analytes, compute multiples of the median, and calculate consistent Down syndrome risks. Assays for the measurement of pregnancy-associated plasma protein A are not standardized and are less precise than those for human chorionic gonadotropin. Participants calculate reliable median equations given sonographer-specific sets of paired crown-rump length and nuchal translucency measurements.

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