scholarly journals Dizygotic Twin Infants: Controversial Case Study Series/Twin Research Reviews: Twin and Non-twin ICSI Conceptions; Emory University Twin Study; Labor in Multiple Pregnancy After Previous C-Section Delivery; Cell-Free DNA Fetal Fraction in Twin Pregnancies/News Reports: Twin Survivor of Auschwitz; Twins Trading Places; Identical Twin Foals; Twins Born in Different Decades; Twins Ambulette Service

2020 ◽  
Vol 23 (3) ◽  
pp. 190-193
Author(s):  
Nancy L. Segal
Keyword(s):  
Twin Study ◽  
Identical Twin ◽  
Cell Free Dna ◽  
Twin Research ◽  
Brain Functions ◽  
Free Dna ◽  
Emory University ◽  
Twin Pregnancies ◽  
Fetal Fraction

AbstractThis article describes a 1930s case study series involving dizygotic female twin infants. The twins’ development was evaluated following periods of intentionally restricted practice and minimal social stimulation. In the opinion of the author of the current article, the study is very unsettling and unacceptable, despite the lack of institutional review boards at that time. This discussion is followed by twin research reviews of recent papers concerning twin and non-twin intracytoplasmic sperm injection conceptions, the Emory University Twin Study of cardiac and brain functions, labor trials in multiple pregnancies after previous C-section delivery and cell-free DNA fetal fraction in twin pregnancies. The article concludes with news items of a twin survivor of Auschwitz, a situation in which twins traded places, the rare birth of identical twin foals, the novel delivery of co-twins in different decades and the Twins Ambulette Service.

scholarly journals Fetal Fraction Estimate in Twin Pregnancies Using Directed Cell-Free DNA Analysis

2013 ◽  
Vol 35 (3) ◽  
pp. 199-203 ◽  
Author(s):  
Craig A. Struble ◽  
Argyro Syngelaki ◽  
Arnold Oliphant ◽  
Ken Song ◽  
Kypros H. Nicolaides
Keyword(s):  
Dna Analysis ◽  
Cell Free Dna ◽  
Free Dna ◽  
Twin Pregnancies ◽  
Fetal Fraction

scholarly journals Cell‐free DNA screening in twin pregnancies: A more accurate and reliable screening tool

2020 ◽  
Vol 40 (10) ◽  
pp. 1321-1329 ◽  
Author(s):  
Jason Chibuk ◽  
Jill Rafalko ◽  
Theresa Boomer ◽  
Ron McCullough ◽  
Graham McLennan ◽  
...  
Keyword(s):  
Screening Tool ◽  
Cell Free Dna ◽  
Free Dna ◽  
Twin Pregnancies

scholarly journals An online tool for fetal fraction prediction based on direct size distribution analysis of maternal cell-free DNA

BioTechniques ◽  
2020 ◽  
Author(s):  
Luca Bedon ◽  
Josef Vuch ◽  
Simeone Dal Monego ◽  
Germana Meroni ◽  
Vanna Pecile ◽  
...  
Keyword(s):  
Size Distribution ◽  
Prenatal Testing ◽  
Distribution Analysis ◽  
Blood Draw ◽  
Noninvasive Prenatal Testing ◽  
Cell Free Dna ◽  
Maternal Cell ◽  
Fetal Dna ◽  
Free Dna ◽  
Fetal Fraction

The discovery of circulating fetal DNA in the plasma of pregnant women has greatly promoted advances in noninvasive prenatal testing. Screening performance is enhanced with higher fetal fraction and analysis of samples whose fetal DNA fraction is lower than 4% are unreliable. Although current approaches to fetal fraction measurement are accurate, most of them are expensive and time consuming. Here we present a simple and cost-effective solution that provides a quick and reasonably accurate fetal fraction by directly evaluating the size distribution of circulating DNA fragments in the extracted maternal cell-free DNA. The presented approach could be useful in the presequencing stage of noninvasive prenatal testing to evaluate whether the sample is suitable for the test or a repeat blood draw is recommended.

Impact of long‐term storage of plasma and cell‐free DNA on measured DNA quantity and fetal fraction

Vox Sanguinis ◽  
2020 ◽  
Vol 115 (7) ◽  
pp. 586-594 ◽  
Author(s):  
Frederik Banch Clausen ◽  
Angela N. Barrett ◽  
Henna V. Advani ◽  
Mahesh Choolani ◽  
Morten Hanefeld Dziegiel
Keyword(s):  
Cell Free Dna ◽  
Long Term Storage ◽  
Free Dna ◽  
Term Storage ◽  
Fetal Fraction

scholarly journals Cell-Free DNA Analysis of Targeted Genomic Regions in Maternal Plasma for Non-Invasive Prenatal Testing of Trisomy 21, Trisomy 18, Trisomy 13, and Fetal Sex

2016 ◽  
Vol 62 (6) ◽  
pp. 848-855 ◽  
Author(s):  
George Koumbaris ◽  
Elena Kypri ◽  
Kyriakos Tsangaras ◽  
Achilleas Achilleos ◽  
Petros Mina ◽  
...  
Keyword(s):  
Trisomy 21 ◽  
Dna Analysis ◽  
Prenatal Testing ◽  
Cost Effective ◽  
Maternal Plasma ◽  
Trisomy 13 ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genomic Regions ◽  
Fetal Fraction

Abstract BACKGROUND There is great need for the development of highly accurate cost effective technologies that could facilitate the widespread adoption of noninvasive prenatal testing (NIPT). METHODS We developed an assay based on the targeted analysis of cell-free DNA for the detection of fetal aneuploidies of chromosomes 21, 18, and 13. This method enabled the capture and analysis of selected genomic regions of interest. An advanced fetal fraction estimation and aneuploidy determination algorithm was also developed. This assay allowed for accurate counting and assessment of chromosomal regions of interest. The analytical performance of the assay was evaluated in a blind study of 631 samples derived from pregnancies of at least 10 weeks of gestation that had also undergone invasive testing. RESULTS Our blind study exhibited 100% diagnostic sensitivity and specificity and correctly classified 52/52 (95% CI, 93.2%–100%) cases of trisomy 21, 16/16 (95% CI, 79.4%–100%) cases of trisomy 18, 5/5 (95% CI, 47.8%–100%) cases of trisomy 13, and 538/538 (95% CI, 99.3%–100%) normal cases. The test also correctly identified fetal sex in all cases (95% CI, 99.4%–100%). One sample failed prespecified assay quality control criteria, and 19 samples were nonreportable because of low fetal fraction. CONCLUSIONS The extent to which free fetal DNA testing can be applied as a universal screening tool for trisomy 21, 18, and 13 depends mainly on assay accuracy and cost. Cell-free DNA analysis of targeted genomic regions in maternal plasma enables accurate and cost-effective noninvasive fetal aneuploidy detection, which is critical for widespread adoption of NIPT.

Factors affecting cell-free DNA fetal fraction and the consequences for test accuracy

2017 ◽  
Vol 31 (14) ◽  
pp. 1865-1872 ◽  
Author(s):  
Fergus Perry Scott ◽  
Melody Menezes ◽  
Ricardo Palma-Dias ◽  
Debbie Nisbet ◽  
Philip Schluter ◽  
...  
Keyword(s):  
Test Accuracy ◽  
Cell Free Dna ◽  
Factors Affecting ◽  
Free Dna ◽  
Fetal Fraction

Cell-Free DNA (cfDNA) Fetal Fraction in Early- and Late-Onset Fetal Growth Restriction

2018 ◽  
Vol 22 (5) ◽  
pp. 613-619 ◽  
Author(s):  
Danila Morano ◽  
Stefania Rossi ◽  
Cristina Lapucci ◽  
Maria Carla Pittalis ◽  
Antonio Farina
Keyword(s):  
Fetal Growth ◽  
Fetal Growth Restriction ◽  
Late Onset ◽  
Growth Restriction ◽  
Cell Free Dna ◽  
Free Dna ◽  
Fetal Fraction
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