scholarly journals Ultrasound-Guided Invasive Procedures in Genetic Prenatal Diagnostics

2011 ◽  
Vol 5 (2) ◽  
pp. 137-139
Author(s):  
Miroslaw Wielgos ◽  
Piotr Wegrzyn
Keyword(s):  
High Risk ◽  
False Positive Rate ◽  
Chorionic Villus ◽  
High Risk Group ◽  
Screening Methods ◽  
Chorionic Villus Sampling ◽  
Invasive Procedures ◽  
Fetal Blood Sampling ◽  
Wide Range ◽  
Positive Rate

ABSTRACT There is a wide range of noninvasive screening methods that aim to identify the subgroup of fetuses that are in a high risk of chromosomal defects. Invasive procedures should be offered to women in the high-risk group identified with the highest possible detection rate and the lowest false-positive rate. The method of choice at 11 + 0 - 13 + 6 weeks is chorionic villus sampling. An early amniocentesis is much more dangerous and should be abandoned. CVS should be performed not earlier than at 11 + 0 weeks of pregnancy. Amniocentesis should be performed no earlier that at 15 + 0 weeks. Earlier procedure is associated with significantly higher rate of talipes equinovarius, amniotic fluid leakage and miscarriage. The umbilical cord insertion is a preferable site for fetal blood sampling. Care must be taken to distinguish between the vein and the artery, and the vein must be sampled, not the artery. The operator's experience is very important issue. It has been postulated that to achieve a reasonable experience one should perform a minimum of 100 chorionic villus samplings, and a reasonable number of invasive procedures should be performed yearly.

scholarly journals Diagnostic Prenatal Invasive Procedures in Obstetrics

2013 ◽  
Vol 7 (4) ◽  
pp. 426-428 ◽  
Author(s):  
Maria Angelica Zoppi
Keyword(s):  
Single Gene ◽  
Chorionic Villus ◽  
Genetic Diagnosis ◽  
Beta Thalassemia ◽  
Pcr Analysis ◽  
Comparative Genomic ◽  
Chorionic Villus Sampling ◽  
Invasive Procedures ◽  
Diagnostic Prénatal ◽  
Fetal Blood Sampling

ABSTRACT In 1977, we performed in Cagliari the first invasive prenatal diagnosis for beta-thalassemia in Europe, using fetal blood sampling by placentacentesis and chain globins analysis at 20th week of gestation. Since then we have performed more than 8,000 fetal diagnoses for beta-thalassemia using placentacentesis, fetoscopy, cordocentesis, cardiocentesis, amniocentesis, transcervical-chorionic villus sampling (TC-CVS), transabdominal (TA-CVS) and preimplantation genetic diagnosis (PGD) by embryo biopsy. Since 1986 we have been using for the beta-thalassemia and other single gene diseases only TA-CVS and PGD and DNA polymerase chain reaction (PCR) analysis. For karyotype we have been using mostly TA-CVS and amniocentesis and traditional cytogenetic analysis, in several cases also fluorescent in situ hybridization (FISH) and comparative genomic hybridization (CGH) array. How to cite this article Monni G, Zoppi MA, Iuculano A. Diagnostic Prenatal Invasive Procedures in Obstetrics. Donald School J Ultrasound Obstet Gynecol 2013;7(4):426-428.

Dual and multiple trisomies: analysis of 38 cases from 13 thousand karyotyped embryos and fetuses

2017 ◽  
pp. 109-115
Author(s):  
N.P. Veropotvelyan ◽  
Keyword(s):  
Prenatal Diagnosis ◽  
High Risk ◽  
Pregnant Women ◽  
Maternal Age ◽  
Chromosomal Abnormalities ◽  
Chorionic Villus ◽  
Primary Group ◽  
Chorionic Villus Sampling ◽  
Missed Abortion ◽  
Reproductive Losses

The study presents data of different authors, as well as its own data on the frequency of multiple trisomies among the early reproductive losses in the I trimester of pregnancy and live fetuses in pregnant women at high risk of chromosomal abnormalities (CA) in I and II trimesters of gestation. The objective: determining the frequency of occurrence of double (DT) and multiple trisomies (MT) among the early reproductive losses in the I trimester of pregnancy and live fetuses in pregnant women at high risk of occurrence of HA in I and II trimesters of gestation; establishment of the most common combinations of diesel fuel and the timing of their deaths compared with single regular trisomy; comparative assessment materinskogo age with single, double and multiple trisomies. Patients and methods. During the period from 1997 to 2016, the first (primary) group of products in 1808 the concept of missed abortion (ST) of I trimester was formed from women who live in Dnepropetrovsk, Zaporozhye, Kirovograd, Cherkasy, Kherson, Mykolaiv regions. The average term of the ST was 8±3 weeks. The average age of women was 29±2 years. The second group (control) consisted of 1572 sample product concepts received during medical abortion in women (mostly residents of Krivoy Rog) in the period of 5-11 weeks of pregnancy, the average age was 32 years. The third group was made prenatally karyotyped fruits (n = 9689) pregnant women with high risk of HA of the above regions of Ukraine, directed the Centre to invasive prenatal diagnosis for individual indications: maternal age, changes in the fetus by ultrasound (characteristic malformations and echo markers HA) and high risk of HA on the results of the combined prenatal screening I and II trimesters. From 11 th to 14 th week of pregnancy, chorionic villus sampling was performed (n=1329), with the 16th week – platsentotsentez (n=2240), 18 th and 24 th week – amniocentesis (n=6120). Results. A comparative evaluation of maternal age and the prevalence anembriony among multiple trisomies. Analyzed 13,069 karyotyped embryonic and fetal I-II trimester of which have found 40 cases of multiple trisomies – 31 cases in the group in 1808 missed abortion (2.84% of total HA), 3 cases including 1 572 induced medabortov and 7 cases during 9689 prenatal research (0.51% of HA). Determined to share the double trisomies preembrionalny, fetal, early, middle and late periods of fetal development. Conclusion. There were no significant differences either in terms of destruction of single and multiple trisomies or in maternal age or in fractions anembrionalnyh pregnancies in these groups. Key words: multiple trisomies, double trisomy, missed abortion, prenatal diagnosis.

Prevention of Preterm Birth

2018 ◽  
Vol 11 (2) ◽  
pp. 95-104
Author(s):  
Ivan D. Ivanov ◽  
Stefan A. Buzalov ◽  
Nadezhda H. Hinkova
Keyword(s):  
Risk Factors ◽  
Preterm Birth ◽  
High Risk ◽  
Medical Science ◽  
Secondary Prophylaxis ◽  
High Risk Group ◽  
Screening Methods ◽  
Perinatal Complications ◽  
Social Significance ◽  
Neonatal Deaths

Summary Preterm birth (PTB) is a worldwide problem with great social significance because it is a leading cause of perinatal complications and perinatal mortality. PTB is responsible for more than a half of neonatal deaths. The rate of preterm delivery varies between 5-18% worldwide and has not decreased in recent years, regardless of the development of medical science. One of the leading causes for that is the failure to identify the high-risk group in prenatal care. PTB is a heterogeneous syndrome in which many different factors interfere at different levels of the pathogenesis of the initiation of delivery, finally resulting in delivery before 37 weeks of gestation (wg). The various specificities of risk factors and the unclear mechanism of initiation of labour make it difficult to elaborate standard, unified and effective screening to diagnose pregnant women at high-risk for PTB correctly. Furthermore, they make primary and secondary prophylaxis less effective and render diagnostic and therapeutic measures ineffective and inappropriate. Reliable and accessible screening methods are necessary for antenatal care, and risk factors for PTB should be studied and clarified in search of useful tools to solve issues of risk pregnancies to decrease PTB rates and associated complications.

scholarly journals Utilizing two-tiered screening for early detection of autism spectrum disorder

Autism ◽  
2017 ◽  
Vol 22 (7) ◽  
pp. 881-890 ◽  
Author(s):  
Meena Khowaja ◽  
Diana L Robins ◽  
Lauren B Adamson
Keyword(s):  
Early Detection ◽  
Young Children ◽  
False Positive ◽  
Screening Tool ◽  
False Positive Rate ◽  
Autism Spectrum ◽  
Screening Methods ◽  
Positive Rate ◽  
Level 1 ◽  
Level 2

Despite advances in autism screening practices, challenges persist, including barriers to implementing universal screening in primary care and difficulty accessing services. The high false positive rate of Level 1 screening methods presents especially daunting difficulties because it increases the need for comprehensive autism evaluations. This study explored whether two-tiered screening—combining Level 1 (Modified Checklist for Autism in Toddlers, Revised with Follow-Up) and Level 2 (Screening Tool for Autism in Toddlers and Young Children) measures—improves the early detection of autism. This study examined a sample of 109 toddlers who screened positive on Level 1 screening and completed a Level 2 screening measure prior to a diagnostic evaluation. Results indicated that two-tiered screening reduced the false positive rate using published Screening Tool for Autism in Toddlers and Young Children cutoffs compared to Level 1 screening alone, although at a cost to sensitivity. However, alternative Screening Tool for Autism in Toddlers and Young Children scoring in the two-tiered screening improved both positive predictive value and sensitivity. Exploratory analyses were conducted, including comparison of autism symptoms and clinical profiles across screening subsamples. Recommendations regarding clinical implications of two-tiered screening and future areas of research are presented.

scholarly journals Basic Diploma in International Ultrasound for Prenatal Diagnosis and Therapy

2013 ◽  
Vol 7 (3) ◽  
pp. 346-348
Author(s):  
Maria Angelica Zoppi
Keyword(s):  
Prenatal Diagnosis ◽  
Chorionic Villus ◽  
Diagnostic Procedures ◽  
Beta Thalassemia ◽  
Chorionic Villus Sampling ◽  
Diagnosis And Therapy ◽  
Fetal Blood Sampling ◽  
Chain Analysis ◽  
Invasive Techniques ◽  
Chromosomal Diseases

ABSTRACT In the Microcitemico Hospital the first prenatal diagnosis in Europe of beta-thalassemia was performed in 1977 using fetal blood sampling and globin chain analysis at 20th week of gestation. Since then, more than 55,000 prenatal invasive procedures were performed in our center for several genetic and chromosomal diseases. In 2011, our department has been introduced as a center for teaching invasive diagnostic procedures under the umbrella of the Ian Donald International University School of Medical Ultrasound. After a period of tutoring for 2 or more weeks, fellow doctors who intend to learn invasive techniques for prenatal diagnosis under the direct supervision of a senior tutor (G. Monni) can receive the basic diploma in invasive prenatal procedures (Fig. 1). In the following study, we describe the training process of the invasive prenatal procedure performed by transabdominal chorionic villus sampling (TA-CVS). How to cite this article Monni G, Zoppi MA, Iuculano A. Basic Diploma in International Ultrasound for Prenatal Diagnosis and Therapy. Donald School J Ultrasound Obstet Gynecol 2013;7(3):346-348.

A Secure Routing Scheme Against Malicious Nodes in Ad Hoc Networks

2018 ◽  
pp. 284-307
Author(s):  
Abdelaziz Amara Korba ◽  
Mohamed Amine Ferrag
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc ◽  
False Positive Rate ◽  
Secure Routing ◽  
Malicious Nodes ◽  
High Detection Rate ◽  
Routing Scheme ◽  
Wide Range ◽  
Positive Rate ◽  
Hoc Networks

This chapter proposes a new cluster-based secure routing scheme to detect and prevent intrusions in ad hoc networks. The proposed scheme combines both specification and anomaly detection techniques to provide an accurate detection of wide range of routing attacks. The proposed secure scheme provides an adaptive response mechanism to isolate malicious nodes from the network. A key advantage of the proposed secure scheme is its capacity to prevent wormhole and rushing attacks and its real-time detection of both known and unknown attacks which violate specification. The simulation results show that the proposed scheme shows high detection rate and low false positive rate compared to other security mechanisms.

scholarly journals Implementation of maternal blood cell-free DNA testing in early screening for aneuploidies

2019 ◽  
Vol 31 (3) ◽  
pp. 283-288
Author(s):  
María M. Gil ◽  
Kypros H. Nicolaides
Keyword(s):  
False Positive Rate ◽  
Maternal Blood ◽  
Screening Methods ◽  
Routine Practice ◽  
Clinical Implementation ◽  
Early Screening ◽  
Test Models ◽  
Lower False Positive Rate ◽  
Implementation Studies ◽  
Positive Rate

AbstractSeveral externally blinded validation and implementation studies in the last 9 years have shown that it is now possible, through analysis of cell-free (cf) DNA in maternal blood, to effectively detect a high proportion of fetuses affected by trisomies 21, 18, and 13 at a much lower false-positive rate (FPR) than all other existing screening methods. This article is aimed at reviewing technical and clinical considerations for implementing cfDNA testing in routine practice, including methods of analysis, performance of the test, models for clinical implementation, and interpretation of results.

Uptake of Noninvasive Prenatal Testing in Chinese Women following Positive Down Syndrome Screening

2014 ◽  
Vol 37 (2) ◽  
pp. 141-147 ◽  
Author(s):  
C.F. Poon ◽  
W.C. Tse ◽  
K.O. Kou ◽  
K.Y. Leung
Keyword(s):  
Down Syndrome ◽  
Chinese Women ◽  
Multivariable Analysis ◽  
Chorionic Villus ◽  
Prenatal Testing ◽  
First Trimester ◽  
Screening Methods ◽  
Chorionic Villus Sampling ◽  
Noninvasive Prenatal Testing ◽  
Down Syndrome Screening

Objectives: To investigate how the introduction of noninvasive prenatal testing (NIPT) influenced women's testing choices following a positive Down syndrome screening. Methods: A retrospective study was conducted to compare differences in the uptake rates of invasive prenatal diagnosis (IPD) or no testing in one public hospital 1 year before (pre-NIPT) and 1 and 2 years after the introduction of NIPT in private in August 2011 using descriptive analysis and a χ2 test. Conventional screening was funded publicly, but NIPT was not. Multivariable binary logistic regression was used to determine factors affecting choices. Results: In pre-NIPT and in years 1 and 2 after the introduction of NIPT, 306, 362 and 401 women who screened positive were seen, respectively. In year 1 and year 2, 12.6 and 26.7% of them underwent NIPT while IPD was decreased by 16.3 and 25.6%, respectively (p < 0.001). Both chorionic villus sampling and amniocentesis decreased in year 1, but only the former in year 2. However, the rate of declining further testing was similar before and after NIPT (p = 0.213). In multivariable analysis, first trimester screening, nulliparity and working women were significant predictors of accepting NIPT, while only nulliparity was a predictor of declining IPD (OR = 0.61). Conclusions: Introduction of NIPT resulted in a significant decrease in IPD for 2 consecutive years.

scholarly journals A prospective clinical trial to compare the performance of dried blood spots prenatal screening for Down’s syndrome with conventional non-invasive testing technology

2017 ◽  
Vol 242 (5) ◽  
pp. 547-553
Author(s):  
Huiying Hu ◽  
Yulin Jiang ◽  
Minghui Zhang ◽  
Shanying Liu ◽  
Na Hao ◽  
...  
Keyword(s):  
High Risk ◽  
False Positive ◽  
False Positive Rate ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Dried Blood Spots ◽  
High Risk Women ◽  
Secondary Screening ◽  
Serum Screening ◽  
Positive Rate

To evaluate, side by side, the efficiency of dried blood spots (DBSs) against serum screening for Down’s syndrome, and then, to construct a two-tier strategy by topping up the fetal cell-free DNA (cfDNA) secondary screening over the high-risk women marked by the primary blood testing to build a practical screening tactic to identify fetal Down’s syndrome. One thousand eight hundred and thirty-seven low-risk Chinese women, with singleton pregnancy, were enrolled for the study. Alpha-fetoprotein and free beta human chorionic gonadotropin were measured for the serum as well as for the parallel DBS samples. Partial high-risk pregnant women identified by primary blood testing (n = 38) were also subject to the secondary cfDNA screening. Diagnostic amniocentesis was utilized to confirm the screening results. The true positive rate for Down’s syndrome detection was 100% for both blood screening methods; however, the false-positive rate was 3.0% for DBS and 4.0% for serum screening, respectively. DBS correlated well with serum screening on Down’s syndrome detection. Three out of 38 primary high-risk women displayed chromosomal abnormalities by cfDNA analysis, which were confirmed by amniocentesis. Either the true detection rate or the false-positive rate for Down’s syndrome between DBS and the serum test is comparable. In addition, blood primary screening aligned with secondary cfDNA analysis, a “before and after” two-tier screening strategy, can massively decrease the false-positive rate, which, then, dramatically reduces the demand for invasive diagnostic operation. Impact statement Children born with Down’s syndrome display a wide range of mental and physical disability. Currently, there is no effective treatment to ease the burden and anxiety of the Down’s syndrome family and the surrounding society. This study is to evaluate the efficiency of dried blood spots against serum screening for Down’s syndrome and to construct a two-tier strategy by topping up the fetal cell-free DNA (cfDNA) secondary screening over the high-risk women marked by the primary blood testing to build a practical screening tactic to identify fetal Down’s syndrome. Results demonstrate that fetal cfDNA can significantly reduce false-positive rate close to none while distinguishing all true positives. Thus, we recommend that fetal cfDNA analysis to be utilized as a secondary screening tool atop of the primary blood protein screening to further minimize the capacity of undesirable invasive diagnostic operations.

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