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.

scholarly journals False Positive Values of Biomarkers of Prenatal Screening on Chromosomopathy as Indicators of a Risky Pregnancy

2011 ◽  
Vol 30 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Jasmina Durković ◽  
Luka Anđelić ◽  
Bojana Mandić ◽  
Denis Lazar
Keyword(s):  
Genetic Screening ◽  
False Positive ◽  
Prenatal Screening ◽  
Protein A ◽  
First Trimester ◽  
Maternal Serum ◽  
Fetal Hypoxia ◽  
Beta Hcg ◽  
First Trimester Of Pregnancy ◽  
Fetal Karyotype

False Positive Values of Biomarkers of Prenatal Screening on Chromosomopathy as Indicators of a Risky PregnancyGenetic screening on chromosomopathy has been performed on 2000 pregnant women in their first trimester of pregnancy by determining Pregnancy associated plasma protein-A and free-beta HCG biomarkers in maternal serum. After obtaining a normal fetal karyotype, the pathological values of the biomarkers have been correlated with other pregnancy disorders, and the possible causes of the positive genetic screening have been tested. 340 false positive biomarkers (17%) have been detected. The increased free-beta HCG (48.24%) had a significant influence. A significant correlation (p > 0.01) between the increased free-beta HCG and bleeding during pregnancy has been established. Complications occurred in 78.52% pregnancies with pathological biomarkers, MISSed in 13.82%, miscarriages in 10.88%, induced pregnancy terminations caused by fetal anomalies in 8.82% and births with disturbed fetal vitality in 45%. The research results have shown a significant correlation (p > 0.01) between the increased value of the free-beta HCG biomarkers and fetal hypoxia. The false positive genetic screening, caused by the increased free-beta HCG, can indicate placental dysfunction and fetal vitality disruption.

scholarly journals The Effect of Down Syndrome Biochemical Markers on Predicting Severity of Preeclampsia

2020 ◽  
Author(s):  
AYSE OZBAN
Keyword(s):  
Down Syndrome ◽  
Pregnant Women ◽  
Biochemical Markers ◽  
First Trimester ◽  
Maternal Serum ◽  
Screening Tests ◽  
Second Trimester ◽  
Study Results ◽  
Second Trimester Screening ◽  
Trimester Screening

Abstract Objective: This study aims to determine whether it is possible to predict preeclampsia by comparing postpartum results and test results of the pregnant women diagnosed with preeclampsia, whose first and/or second trimester screening tests were accessible, and to demonstrate the predictability of severity and week of onset.Background: 204 patients underwent renal transplantation in our center and 84 of them were female. Five of our patients (one of them had two births) gave birth to a total of 6 pregnancies.Method: 135 patients were diagnosed with preeclampsia and their first and/or second trimester screening tests were accessible, and 366 control participants gave birth to a healthy baby between 37-41 weeks after standard follow-up period for pregnancy and their screening tests were also accessible.Results: The study results show that the first trimester maternal serum PAPP-A level is significantly low in preeclamptic pregnant women, and that the second trimester maternal serum AFP and hCG levels are significantly high and uE3 levels are significantly low The results also suggest that the first and second trimester Down syndrome biochemical markers can be used in preeclampsia screening.Conclusion: Among these markers, uE3 is the parameter which affects the possibility of preeclampsia the most. However, the first and second trimester Down syndrome biochemical markers are not effective in predicting the severity and onset week of preeclampsia.

scholarly journals First Trimester Biochemical Screening for Trisomy 21: The Role of Free Beta hCG, Alpha Fetoprotein and Pregnancy Associated Plasma Protein A

1994 ◽  
Vol 31 (5) ◽  
pp. 447-454 ◽  
Author(s):  
K Spencer ◽  
D A Aitken ◽  
J A Crossley ◽  
G McCaw ◽  
E Berry ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Plasma Protein ◽  
Human Chorionic Gonadotropin ◽  
Trisomy 21 ◽  
False Positive Rate ◽  
Protein A ◽  
First Trimester ◽  
Serum Markers ◽  
Maternal Serum ◽  
Detection Rates

The potential efficacy of screening for trisomy 21 in the first trimester, using maternal serum markers α fetoprotein, free β human chorionic gonadotropin, unconjugated oestriol and pregnancy associated plasma protein A, was studied in an unselected population of women between the seventh and fourteenth week of gestation. Using a combination of α fetoprotein and free β human chorionic gonadotropin, 53% of affected pregnancies could be identified at a false positive rate of 5%. Unconjugated oestriol and pregnancy associated plasma protein A levels were lower in cases of trisomy 21, but their inclusion with other markers did not significantly improve detection rate. Monitoring the same pregnancies also in the second trimester showed that screening in the first trimester identified the same cases as in the second. We conclude that first trimester screening using free β human chorionic gonadotropin and α fetoprotein, is a viable possibility and will lead to detection rates in excess of 50%. Prospective studies are needed to confirm these observations.

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 <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.

Influence of Weight of Pregnant Women on First Trimester Biochemical Markers Values

2018 ◽  
Vol 68 (12) ◽  
pp. 2836-2838
Author(s):  
Dan Navolan ◽  
Cringu Antoniu Ionescu ◽  
Adrian Carabineanu ◽  
Florin Birsasteanu ◽  
Octavian Cretu ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Biochemical Markers ◽  
Risk Evaluation ◽  
Protein A ◽  
Inverse Correlation ◽  
First Trimester ◽  
Maternal Weight ◽  
Beta Hcg ◽  
Evaluation Algorithm ◽  
Calculation Software

Values of first trimester biochemical markers (PAPP-A and free b-hCG) concentration are included in aneuploidies risk evaluation algorithm. Since both markers are produced by the fetus and placenta their concentration depends on the volume in which they are dissolved, respectively the weight of the pregnant women. Our study aimed to analyze the influence of maternal weight on first trimester biochemical markers concentration and the ability of the risk calculation software to correct this influence. Pregnancy-associated protein A (PAPP-A) and free � chorionic gonadotropin hormone (free � hCG) first trimester sera concentration respectively weight were measured in 1629 pregnant women. First trimester PAPP-A and free beta hCG concentrations inverse correlate with weight of pregnant women rho=-0.33, p[0.0001, respectively rho=-0.18, p[0.0001. Weight of pregnant women inversely correlates with multiple of median (MoM) values of first trimester markers too: rho=-0.38, p[0.0001 (PAPP-A), respectively rho=-0.17, p[0.0001 (free-b-hCG). The software counterbalances the influence of weight on biochemical markers values. PAPP-A corrected MoM (MoMc) values don�t inversely correlate with the weight (rho=-0.03, p=0.12), whereas free � hCG MoMc values showed an extremely weak inverse correlation (rho=-0.08, p=0.0008). The software counterbalances the influence of weight on PAPP-A values, whereas an extremely weak but insignificant inverse correlation between weight and free-beta hCG values persists after correction.

scholarly journals Missed Down Syndrome Cases after First Trimester False-Negative Screening—Lessons to be Learned

Medicina ◽  
2020 ◽  
Vol 56 (4) ◽  
pp. 199
Author(s):  
Anca Angela Simionescu ◽  
Ana Maria Alexandra Stanescu
Keyword(s):  
Down Syndrome ◽  
Biochemical Markers ◽  
Trisomy 21 ◽  
False Negative ◽  
First Trimester ◽  
Low Risk ◽  
Patient Choice ◽  
Ductus Venosus ◽  
Risk Calculation ◽  
Software Programs

Background and Objectives: Here, we performed a descriptive analysis of Down syndrome (DS) cases that were misdiagnosed and/or false-negative diagnosed after first trimester traditional screening via risk evaluation using ultrasound, biochemical markers, and different software programs. Our objective was to demonstrate the clear need to improve the application of prenatal DS screening programs using standardized ultrasound measurements, accurate pregnancy dating, analytical immunoassay performance, and properly selected medians. Materials and Methods: We performed a database search for the period 2010–2015 to analyze DS cases that were false-negative diagnosed after the first trimester of pregnancy, before the introduction of cell free fetal DNA-based tests by Romanian laboratories in 2015. First-trimester screening was performed using two software programs for prenatal DS risk calculation: Astraia and Prisca. The rationale for using both software programs was to assess the full risk using the maternal age combined test (based on nuchal translucency thickness, nasal bone, ductus venosus flow, tricuspid flow, free beta-human chorionic gonadotropin level, and serum pregnancy-associated plasma protein-A) and, in some cases, the triple test. Results: We identified seven DS cases that exhibited low risk for trisomy 21, and 6540 cases with a low risk for trisomy 21 and euploid fetus in the first trimester. Using Astraia software, 14 cases were diagnosed, and three cases were missed after risk calculation. Using Prisca software, four cases were missed. Additionally, one neonate had a missed prenatal diagnosis of atrio-ventricular canal defect. Conclusion: In Romania, the evaluation of DS risk depends on patient choice (without knowing the accuracy of the utilized tests) and on the operators’ skills. Both Astraia and Prisca software were developed by experts, who can prove their performance in DS screening. However, even in an ideal situation, false-negative results are possible. The application of first and second-trimester combined screening based on biochemical markers could be improved by the implementation of standardized protocols, professional guidelines for test application, and audit control.

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