Screening for Down syndrome in the first trimester

1995 ◽  
Vol 7 (6) ◽  
pp. 1413 ◽  
Author(s):  
KJ Powell ◽  
JG Grudzinskas
Keyword(s):  
Down Syndrome ◽  
First Trimester ◽  
Maternal Blood ◽  
Maternal Serum ◽  
Published Data ◽  
Maternal Serum Screening ◽  
Ultrasound Findings ◽  
Serum Screening ◽  
Associated Proteins ◽  
Trimester Screening

Second-trimester maternal serum screening for Down syndrome is now well established, and permits detection of up to 70% of cases. The disadvantage of this sort of screening is that the timing of maternal blood sampling is relatively late (after 15 weeks). There is an accumulating body of evidence to suggest that in the first trimester concentrations of a number of pregnancy-associated proteins and hormones differ in chromosomally normal and abnormal pregnancies. A first-trimester maternal serum screening test for Down syndrome may therefore be possible. In addition, new methods of screening have recently been described based on ultrasound findings at 11 to 13 weeks of gestation. This review article presents a discussion of published data on the feasibility of first-trimester screening for Down syndrome.

scholarly journals Fetal Down syndrome screening models for developing countries; Part I: Performance of Maternal Serum Screening

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Chanane Wanapirak ◽  
Wirawit Piyamongkol ◽  
Supatra Sirichotiyakul ◽  
Fuanglada Tongprasert ◽  
Kasemsri Srisupundit ◽  
...  
Keyword(s):  
Developing Countries ◽  
Down Syndrome ◽  
Reference Range ◽  
First Trimester ◽  
Maternal Serum ◽  
Second Trimester ◽  
First Trimester Screening ◽  
Maternal Serum Screening ◽  
Serum Screening ◽  
Trimester Screening

Abstract Background To identify the performance of fetal Down syndrome (DS) screening for developing countries. Methods A prospective study on MSS (maternal serum screening) with complete follow-ups (n = 41,924) was conducted in 32 network hospitals in the northern part of Thailand. Various models of MSS were tested for performance. Results MSS based on Caucasian reference range resulted in very high false positive rate (FPR; 13%) in our country, compared to the rate of 7.8% with our own (Thai) reference range, whereas the detection rate was comparable. As individual screening, C-S (contingent first trimester screening including PAPP-A, and free beta-hCG, classified as a) high risk [> 1:30], indicated for invasive diagnosis; b) intermediate risk [1:30–1500], indicated for STS; and c) low risk [< 1:1500], need no further tests.) was the most effective model (sensitivity 84.9%, FPR 7.7%) but nearly one-third needed the second trimester test (STS) because of intermediate results. Additionally, about one-third had their first visits in the second trimester and had no chance of FTS (first trimester screening). C-S plus STS had a sensitivity of 82.4% and FPR 8.1% whereas independent first and second trimester screening model (I-S) gave the sensitivity of 78.4% and FPR of 7.5% but was much more convenient and practical. Conclusion C-S plus STS was the most effective models while I-S model was also effective and may be better for developing countries because of its simplicity and feasibility.

Prenatal screening for Down syndrome: should first trimester ultrasound replace maternal serum screening?

1996 ◽  
Vol 47 ◽  
pp. S37-S39 ◽  
Author(s):  
Françoise Muller ◽  
Marc Dommergues ◽  
Laurence Bussières ◽  
Philippe Aegerter ◽  
Bernard Le Fiblec ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Prenatal Screening ◽  
First Trimester ◽  
Maternal Serum ◽  
Maternal Serum Screening ◽  
Serum Screening ◽  
First Trimester Ultrasound

scholarly journals Double-monoclonal immunofluorometric assays for pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/proMBP) complex in first-trimester maternal serum screening for Down syndrome

1997 ◽  
Vol 43 (12) ◽  
pp. 2323-2332 ◽  
Author(s):  
Qiu-Ping Qin ◽  
Michael Christiansen ◽  
Claus Oxvig ◽  
Kim Pettersson ◽  
Lars Sottrup-Jensen ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Plasma Protein ◽  
Basic Protein ◽  
Protein A ◽  
First Trimester ◽  
Maternal Serum ◽  
Major Basic Protein ◽  
Maternal Serum Screening ◽  
Detection Rates ◽  
Serum Screening

Abstract Four double-monoclonal time-resolved immunofluorometric assays (TrIFMAs) have been developed for the specific determination of pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/proMBP) complex in first-trimester maternal serum samples. The assays have a functional sensitivity of &lt;4 mIU/L and a working range from 4 to 1000 mIU/L. These 4 assays, together with a polyclonal sandwich TrIFMA, were compared for their ability to discriminate between normal pregnancies (n = 149) and pregnancies carrying a Down syndrome fetus (n = 36) in maternal serum screening samples from gestational weeks 4–13. In 26 Down syndrome pregnancies from gestational weeks 7–12, the median PAPP-A multiples of the median concentration in controls (MoMs) determined by monoclonal antibody combinations 234–3/234–2*, 234–4/234–2*, 234–4/234–5*, and 234–5/234–6* were 0.35, 0.37, 0.42, and 0.44, respectively, whereas the median MoM determined by the polyclonal assay was 0.56. ROC curve analysis also showed that better overall diagnostic accuracy and detection rates were achieved by the monoclonal TrIFMAs than by the polyclonal TrIFMA. This report is the first to describe assays that specifically measure PAPP-A/proMBP complex without possible interference from other proMBP-containing complexes.

Prenatal Screening for Down Syndrome in Australia

Ultrasound ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 167-171
Author(s):  
Debbie L Nisbet ◽  
Andrew McLennan
Keyword(s):  
Down Syndrome ◽  
Prenatal Screening ◽  
False Positive Rate ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Maternal Serum ◽  
Screening Tests ◽  
Maternal Serum Screening ◽  
Serum Screening ◽  
Maternal Preference

Prenatal screening for Down syndrome should be offered to all pregnant women. The screening option chosen will be influenced by maternal preference, local availability of tests, and the gestation at which the pregnant woman presents. Screening tests take into account the effect of maternal age on Down syndrome risk. The combined first trimester screen using nuchal translucency and first trimester maternal serum screening can achieve a detection rate for Down syndrome of 90% with a 5% false positive rate, when performed by appropriately trained individuals. Midtrimester maternal serum screening is a good screening option for women unable to undergo the combined first trimester screen.

Prenatal serum screening for Down syndrome and neural tube defects in the United States: Changes in utilization patterns from 2012 to 2020

2021 ◽  
pp. 096914132110316
Author(s):  
Nathalie Lepage ◽  
Philip Wyatt ◽  
Edward R Ashwood ◽  
Robert G Best ◽  
Thomas Long ◽  
...  
Keyword(s):  
United States ◽  
Down Syndrome ◽  
First Trimester ◽  
The United States ◽  
Maternal Serum ◽  
Second Trimester ◽  
Maternal Serum Screening ◽  
Cell Free Dna ◽  
Free Dna ◽  
Serum Screening

Objective To compile current usage of serum-based prenatal screening for Down syndrome in the United States and compare it with results from a similar 2011/2012 survey. Setting The College of American Pathologists maternal screening proficiency testing survey includes a supplemental question on the first of three yearly distributions. Methods Information regarding tests offered and the monthly number of pregnancies tested for US-based laboratories were reviewed. Results were stratified by size of laboratory, tests offered, and pregnancies tested. Findings were compared to an earlier survey. Results Fifty-six laboratories reported they will have screened 1,131,336 pregnancies in 2020. Of these, 36% are screened by stand-alone first trimester testing, 48% by stand-alone second trimester testing, and 16% using tests that integrate results from both trimesters. Eighty percent of all serum screens were provided by the five laboratories that performed the most screens (at least 50,000). These five performed similar proportions of first or second trimester screens (42.2% and 41.8%, respectively). Compared to eight years earlier, there are now 54% fewer laboratories. Pregnancies screened using the first trimester, second trimester, and integrated protocols were lower by 27%, 69%, and 72%, respectively. The serum screening activity in the US showed a 62% decrease from 2012 levels. During 2012–2020, the number of cell-free DNA tests increased from negligible to 1,492,332. Conclusions Maternal serum screening for common aneuploidies has changed significantly in eight years with fewer laboratories, a shift toward larger laboratories and a 2.5-fold reduction in pregnancies tested, likely due to the introduction of cell-free DNA screening.

Prenatal Screening Technologies and Test Issues

2017 ◽  
Author(s):  
Danielle LaGrave ◽  
Patricia L. Devers Winters ◽  
Geralyn Lambert-Messerlian
Keyword(s):  
Down Syndrome ◽  
Prenatal Screening ◽  
Molecular Genetic ◽  
First Trimester ◽  
Maternal Serum ◽  
Patient Specific ◽  
Maternal Serum Screening ◽  
Plasma Fraction ◽  
Cell Free Fetal Dna ◽  
Serum Screening

Maternal serum screening began with the measurement of serum alpha fetal protein to detect open neural tube defects, which led to the implementation of routine serum-based prenatal screening in the second trimester for Down syndrome. Advances via combined and integrated screening allowed for the first-trimester detection of both Down syndrome and trisomy 18. Next-generation sequencing has enabled the identification of aneuploidies in circulating cell-free fetal DNA from the plasma fraction of maternal whole blood. This breakthrough in molecular genetic testing, commonly referred to as noninvasive prenatal testing, has revolutionized prenatal screening and testing for genetic disorders without posing additional risk to the pregnancy. This chapter reviews the history of maternal serum screening, the disorders it can detect, the methods of calculating patient-specific risk, and reasons for recalculation or adjustment of risk. This chapter also reviews of cell-free DNA-based testing for fetal aneuploidies, including its limitations and potential.

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