Second-trimester prenatal screening for trisomy 21 using biochemical markers: a 7-year experience in one cytogenetic laboratory

2006 ◽  
Vol 26 (4) ◽  
pp. 308-312 ◽  
Author(s):  
Hélène Marical ◽  
Nathalie Douet-Guilbert ◽  
Karine Bages ◽  
Michel Collet ◽  
Marie-Josée Le Bris ◽  
...  
Keyword(s):  
Biochemical Markers ◽  
Trisomy 21 ◽  
Prenatal Screening ◽  
Second Trimester

Correlation of ultrasound findings and biochemical markers in the second trimester of pregnancy in fetuses with trisomy 21

2002 ◽  
Vol 22 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Vivienne L. Souter ◽  
David A. Nyberg ◽  
Amira El-Bastawissi ◽  
Arthur Zebelman ◽  
Fred Luthhardt ◽  
...  
Keyword(s):  
Biochemical Markers ◽  
Trisomy 21 ◽  
Second Trimester ◽  
Ultrasound Findings

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 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.

Does Active Smoking Influence the Second Trimester Biochemical Markers Concentrations?

2017 ◽  
Vol 68 (10) ◽  
pp. 2234-2236
Author(s):  
Dan Navolan ◽  
Florin Birsasteanu ◽  
Adrian Carabineanu ◽  
Octavian Cretu ◽  
Diana Liana Badiu ◽  
...  
Keyword(s):  
Pregnant Woman ◽  
Pregnant Women ◽  
Cigarette Smoke ◽  
Chorionic Gonadotropin ◽  
Reference Values ◽  
Biochemical Markers ◽  
Smoking Status ◽  
Active Smoking ◽  
Second Trimester ◽  
Harmful Effects

Cigarette smoke contains over 7000 different substances some of them exerting harmful effects on embryo and pregnant woman. Nowadays 15 % of adult people and around 10-15% of pregnant women smoke. Previous studies showed that cigarette smoke compounds could exert pharmacodinamic effects and influence some of the second trimester biochemical markers concentration. Therefore there is a need to adjust the reference values of second trimester markers depending of the smoker status. The aim of our study was to analyse which of the markers are influenced by smoking and whether the software used to calculate the risk for aneuploidies is able to counterbalance this influence. Alpha-fetoprotein (AFP), chorionic gonadotropin hormone (hCG) and free estriol (uE3) values were measured in second trimester sera of 1242 pregnant women: 1089 non-smokers and 153 smokers. Only hCG second trimester values were influenced by smoking whereas AFP and uE3 values were not. The correction of medians according to the smoking status was able to counterbalance this effect.

Is there a Need for Own Median Calculation in the Second Trimester Biochemical Markers Screening?

2017 ◽  
Vol 68 (5) ◽  
pp. 1070-1072
Author(s):  
Dan Navolan ◽  
Mirela Nicolov ◽  
Simona Vladareanu ◽  
Ioana Ciohat ◽  
Marius Craina ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Gestational Age ◽  
Biochemical Markers ◽  
Biochemical Marker ◽  
Second Trimester ◽  
Established Method ◽  
Crown Rump Length ◽  
The Difference ◽  
Fetal Aneuploidies ◽  
Singleton Pregnancies

Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fetal medicine. The aim of our study was to analyze if the medians recommended by the manufacturers are adequate to perform an accurate screening or if there is a need for own laboratory medians calculation in second trimester biochemical marker screening.Sera were collected between 14 wp and 22 wp from 3374 singleton pregnancies. We analyzed three second trimester biochemical markers (AFP, hCG and free Estriol) concentration in all pregnant women and in a subgroup of pregnant women in which gestational age was determined based on crown-rump length. Our results showed that for all biochemical markers the difference between the manufacturer and the own calculated median was lower than 10% excepting the hCG value in the group of pregnant women in which the gestational age was determined on basis of crown-rump-length. Our results show it is recommended to replace the values of the median for hCG measurement with the own laboratory calculated medians. This does not seem to be necessary in the case of AFP and free Estriol measurement.

scholarly journals Efficiency of non-invasive prenatal screening in pregnant women at advanced maternal age

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hui Zhu ◽  
Xiaoxiao Jin ◽  
Yuqing Xu ◽  
Weihua Zhang ◽  
Xiaodan Liu ◽  
...  
Keyword(s):  
High Risk ◽  
Pregnant Women ◽  
Predictive Value ◽  
Trisomy 21 ◽  
Maternal Age ◽  
Prenatal Screening ◽  
Advanced Maternal Age ◽  
Youden Index ◽  
Non Invasive ◽  
Sensitivity Specificity

Abstract Background Non-invasive prenatal screening (NIPS) is widely used as the alternative choice for pregnant women at high-risk of fetal aneuploidy. However, whether NIPS has a good detective efficiency for pregnant women at advanced maternal age (AMA) has not been fully studied especially in Chinese women. Methods Twenty-nine thousand three hundred forty-three pregnant women at AMA with singleton pregnancy who received NIPS and followed-up were recruited. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), receiver operating characteristic (ROC) curves and the Youden Index for detecting fetal chromosomal aneuploidies were analyzed. The relationship between maternal age and common fetal chromosomal aneuploidy was observed. Results The sensitivity, specificity, PPV, NPV of NIPS for detecting fetal trisomy 21 were 99.11, 99.96, 90.98, and 100%, respectively. These same parameters for detecting fetal trisomy 18 were 100, 99.94, 67.92, and 100%, respectively. Finally, these parameters for detecting trisomy 13 were 100, 99.96, 27.78, and 100%, respectively. The prevalence of fetal trisomy 21 increased exponentially with maternal age. The high-risk percentage incidence rate of fetal trisomy 21 was significantly higher in the pregnant women at 37 years old or above than that in pregnant women at 35 to 37 years old. (Youden index = 37). Conclusion It is indicated that NIPS is an effective prenatal screening method for pregnant women at AMA.

scholarly journals Optimization of regional median equations of prenatal screening markers for trisomy 21 in a Chinese population

Medicine ◽  
2018 ◽  
Vol 97 (35) ◽  
pp. e12045
Author(s):  
Liangpu Xu ◽  
Hailong Huang ◽  
Lin Zheng ◽  
Deqin He ◽  
Na Lin ◽  
...  
Keyword(s):  
Trisomy 21 ◽  
Chinese Population ◽  
Prenatal Screening

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.

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