China
Africa
Explore chapters and articles related to this topic
Prenatal Diagnosis and Screening for Aneuploidy
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Sarah Harris, Angie Jelin, Neeta Vora
First-trimester ultrasound (with NT). Cell-free fetal DNA screening. First- or second-trimester multiple marker screening is not sensitive nor clinically useful for detecting trisomy 13. Accurate ultrasound is usually 90% sensitive for trisomy 13.
Assessment of fetal genetic disorders
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Teresa Martino, J. Pratt Rossiter, Karin J. Blakemore
In recent years, there has been a greater focus on using cell-free fetal DNA or RNA within the maternal plasma or serum for use in prenatal DNA diagnosis. In 1997, Lo et al. demonstrated that cell-free fetal DNA circulates within the plasma and serum of pregnant women (121). Fetal DNA can be detected within the maternal circulation as early as 7 weeks of gestation (122). In 2009, Tobias et al. reported a method of specific magnetic bead-based capture of free fetal DNA from maternal plasma. The team developed a magnetic capture hybridization technique using specific hybridization primers for the extraction of fetal DNA from maternal plasma, which is almost twice as efficient as older methods (123). Both forms of nucleic acids may prove useful for accurate fetal gender determination and fetal RhD blood typing. Their utility for screening and/or detection of fetal aneuploidy remains under active investigation.
Obesity
Published in Judy Bothamley, Maureen Boyle, Medical Conditions Affecting Pregnancy and Childbirth, 2020
Detailed anomaly scans, together with serum screening, are offered in view of the increased incidence of congenital abnormalities in women who are obese. However, adipose tissue can absorb ultrasound energy, and in obesity the image quality may be compromised51. Transvaginal ultrasound may give better results when measuring nuchal translucency11. The potential for errors of diagnosis from ultrasound assessment for structural congenital abnormalities should be discussed with the woman11. CVS and amniocentesis may also be appropriate, but these are more difficult procedures in an obese woman47, therefore the risks of failure or complications may be raised. Non-invasive antenatal testing which identifies cell free fetal DNA from a maternal blood sample is used for diagnosis of Down syndrome and other aneuploi-dies. However, it appears this test may be less effective for diagnosis in pregnancies complicated by obesity70.
Focus on the frontier issue: progress in noninvasive prenatal screening for fetal trisomy from clinical perspectives
Published in Critical Reviews in Clinical Laboratory Sciences, 2023
Meng Tian, Lei Feng, Jinming Li, Rui Zhang
The discovery of cell-free fetal DNA (cffDNA) in maternal blood and the rapid development of massively parallel sequencing (MPS) have provided unprecedented opportunities for noninvasive prenatal genetic testing of common fetal trisomy disorders (Figure 1(A)) [7]. Noninvasive prenatal screening (NIPS), also called noninvasive prenatal testing (NIPT), is a risk-free method based on the presence of cell-free DNA (cfDNA) in the plasma of pregnant women. This method aims to detect any functional or structural abnormalities in the developing fetus as early as possible to guide clinical decision-making [8,9]. The risk of fetal chromosomal aneuploidy can be calculated by collecting maternal peripheral blood, extracting cfDNA, and performing next-generation sequencing (NGS) technology supplemented by bioinformatics analysis [9]. The diagnostic procedure is illustrated in Figure 1(B).
Clinical application of noninvasive prenatal testing in twin pregnancies: a single-center experience
Published in Expert Review of Molecular Diagnostics, 2023
Yanmei Luo, Bin Hu, Yang Long, Yan Pan, Lupin Jiang, Wei Xiong, Huanhuan Xu, Liang Xu, Dan Wang
Since the first discovery of cell-free DNA (cfDNA) by Lo et al, including the fetal fraction in maternal plasma in 1997 [14], noninvasive prenatal testing (NIPT) based on next-generation sequencing (NGS) of cell-free fetal DNA (cffDNA) was used worldwide to screen for common fetal chromosomal aneuploidies [15–19]. Compared with traditional serological screening, NIPT has the advantages of high sensitivity, high specificity, and noninvasiveness. Therefore, it has good clinical application value and is also the first choice for pregnant women. Recently, the American College of Obstetricians and Gynecologists (ACOG) and the International Society for Prenatal Diagnosis (ISPD) published international guidelines for aneuploidy screening that support the use of NIPT in twin pregnancies [20,21]. Recent studies have also shown that the performance of NIPT in twin pregnancies is superior to traditional prenatal screening, and it is almost as accurate as singletons pregnancies [22,23]. Despite the promise of NIPT in twin pregnancies, there are only limited publications describing the actual performance of NIPT as first-line screening in large twin pregnancies [24]. The present study aimed to discuss the feasibility and clinical application of NIPT in fetal aneuploidy screening in twin pregnancies. Meanwhile, it provides data and experience for the clinical application of prenatal twins screening.
Research Progress of Cell-Free Fetal DNA in Non-Invasive Prenatal Diagnosis of Thalassemia
Published in Hemoglobin, 2023
Dewen Liu, Chen Nong, Fengming Lai, Yulian Tang, Taizhong Wang
In 1997, Lo et al. of the University of Hong Kong detected the Y sequence in the plasma of pregnant women carrying male fetuses, thus revealing the presence of cell-free fetal DNA (cffDNA) in maternal plasma [5]. Lo et al. [6] confirmed the presence of fetal genome-wide genetic mutations in maternal plasma in 2010, which officially opened a new era of noninvasive prenatal diagnosis (NIPD) of thalassemia. The presence of cffDNA can be detected in the 9th week of pregnancy [7]. With the increase in pregnancy, the content of cffDNA will change, and the content of cffDNA accounts for about 9–20% of maternal plasma throughout the pregnancy period [8]. At present, noninvasive prenatal diagnosis technology has been widely used in paternity tests [9], trisomy [10], cystic fibrosis [11], fetal Rhesus-D (RhD) [12], fetal sex [13], and some monogenic disorders [14,15]. With the progress of sequencing technology, noninvasive prenatal diagnosis based on cell-free fetal DNA has become a more mature diagnosis scheme. At present, there are four research ideas of prenatal diagnosis of thalassemia based on cffDNA: (1) Detection of patrilineal genetic mutations in maternal plasma; (2) Detection of the proportion of wild type alleles and mutant alleles in maternal plasma; (3) Determination of fetal genotypes by linkage disequilibrium single nucleotide polymorphism (SNP) based on pedigree probands; 4. Prediction of fetal genotypes based on bioinformatics linkage disequilibrium SNP.