Correlation and Overlapping between Nuchal Translucency and Triple Test among Down Syndrome-Affected Pregnancies

2003 ◽  
Vol 18 (3) ◽  
pp. 196-200 ◽  
Author(s):  
Arie Herman ◽  
Eliezer Dreazen ◽  
Yosef Tovbin ◽  
Orit Reish ◽  
Ian Bukovsky ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Nuchal Translucency ◽  
Triple Test

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.

Practice Tips for Measuring the Nuchal Translucency

Ultrasound ◽  
2008 ◽  
Vol 16 (4) ◽  
pp. 220-225 ◽  
Author(s):  
Debbie Nisbet
Keyword(s):  
Down Syndrome ◽  
Nasal Bone ◽  
Nuchal Translucency ◽  
Operator Technique ◽  
Increased Risk ◽  
Fetal Nasal Bone ◽  
Form Part ◽  
The Uk ◽  
Bone Assessment ◽  
Down Syndrome Screening

In some countries, measurement of nuchal translucency (NT) is incorporated into national antenatal screening programmes to help detect pregnancies at increased risk of Down syndrome. Accurate measurement of the NT requires a specific technique. This article is an illustrated practical guide outlining the steps required for measuring the NT; it provides useful tips for improving operator technique and advises how to avoid common pitfalls. Although fetal nasal bone assessment does not currently form part of official Down syndrome screening programmes (in Australia or the UK), it is included here as debate about its usefulness continues.

scholarly journals Impact of Ductus Venosus Assessment in Screening Down Syndrome Protocols: An Improved Strategy in a Fetal Medicine Unit

2009 ◽  
Vol 3 (2) ◽  
pp. 10-17 ◽  
Author(s):  
Mónica Echevarria ◽  
Carmen Comas ◽  
M Angeles Rodríguez ◽  
Joan Nicolau ◽  
Bernat Serra ◽  
...  
Keyword(s):  
Down Syndrome ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Serum Biochemistry ◽  
Screening Strategy ◽  
Maternal Serum ◽  
Ductus Venosus ◽  
Early Evaluation ◽  
Invasive Test ◽  
Screening Efficiency

ABSTRACT Objective To estimate the improvement in screening efficiency when ductus venosus (DV) Doppler studies are added to existing Down syndrome (DS) screening protocols. Methods First-trimester combined screening for trisomy 21 was prospectively carried out, from October 2003 to March 2008, in 8842 consecutive singleton pregnancies attended in our tertiary reference center. The nuchal translucency (NT) and the pulsatility index for veins for DV were calculated. The maternal serum biochemistry was measured using the Kryptor analyzer, at the same time of the scan (one step strategy) or before it (two step strategy). The detection rate (DR) and false-positive rates for standard screening strategy (maternal age, NT and biochemistry) and the same strategy but including DV assessment were calculated. Results Successful DV assessment was possible in the 95.3% of cases, representing a total of 8426 cases. Down syndrome was identified in 34 pregnancies (prevalence of DS 1:250). For a fixed screen positive rate of 5%, the addition of the DV assessment improves the DR from 85 to 94% and, for a fixed DR of 85%, it reduces the number of unnecessary invasive tests from 3.7 to 3.2%. Conclusion Early evaluation of DV can be introduced to standard DS screening strategies in experienced centers as a first level test to reduce invasive test rate derived from the existing protocols.

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.

Prenatal Screening Strategies for Down Syndrome: Many Options but Few Answers

1998 ◽  
Vol 4 (3) ◽  
pp. 229
Author(s):  
Euan M. Wallace
Keyword(s):  
Down Syndrome ◽  
Prenatal Screening ◽  
New South ◽  
South Australia ◽  
Nuchal Translucency ◽  
Second Trimester ◽  
Mental Handicap ◽  
South Wales ◽  
Screening Strategies ◽  
Serum Screening

Down syndrome is the single most common cause of severe mental handicap in Australia. Prenatal screening for Down syndrome is therefore an important component of modern antenatal care. However, while effective second trimester serum screening for Down syndrome has been available in Australia for almost a decade it appears that the majority of Australian women, particularly those outside South Australia and New South Wales, are still not offered it. Newer methods of screening have been recently described and are already being offered in routine clinical practice. These methods, including nuchal translucency, will afford results earlier in pregnancy than second trimester serum screening and so are attractive to women. However, available evidence suggests that nuchal translucency may not perform as well as second trimester serum screening and further evaluation of the newer screening strategies in an Australian population is urgently required. Alteration of practice prior to such an evaluation is simply not warranted at this time.

First-trimester screening for Down syndrome with ductus venosus Doppler studies in addition to nuchal translucency and serum markers

2005 ◽  
Vol 25 (10) ◽  
pp. 901-905 ◽  
Author(s):  
Antoni Borrell ◽  
Anna Gonce ◽  
Josep M. Martinez ◽  
Virginia Borobio ◽  
Albert Fortuny ◽  
...  
Keyword(s):  
Down Syndrome ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Serum Markers ◽  
Ductus Venosus ◽  
Doppler Studies ◽  
First Trimester Screening ◽  
Trimester Screening

P17.03: First trimester biochemical screening combined with fetal nuchal translucency, nasal bone and maternal age for Down syndrome in singelton pregnancies

2010 ◽  
Vol 36 (S1) ◽  
pp. 234-234
Author(s):  
K. Natasa ◽  
Z. Mikovic ◽  
M. Marinkovic ◽  
B. Damnjanovic-Pazin ◽  
Z. Milovanovic ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Maternal Age ◽  
Nasal Bone ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Biochemical Screening
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