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Acta Obstetricia Et Gynecologica... Jan 2017The aim of this study was to review the performance of non-invasive prenatal testing (NIPT) for detection of trisomy 21, 18 and 13 (T21, T18 and T13) in a general... (Meta-Analysis)
Meta-Analysis Review
Analysis of cell-free fetal DNA in maternal blood for detection of trisomy 21, 18 and 13 in a general pregnant population and in a high risk population - a systematic review and meta-analysis.
INTRODUCTION
The aim of this study was to review the performance of non-invasive prenatal testing (NIPT) for detection of trisomy 21, 18 and 13 (T21, T18 and T13) in a general pregnant population as well as to update the data on high-risk pregnancies.
MATERIAL AND METHODS
Systematic review and meta-analysis. PubMed, Embase and the Cochrane Library were searched. Methodological quality was rated using QUADAS and scientific evidence using GRADE. Summary measures of diagnostic accuracy were calculated using a bivariate random-effects model.
RESULTS
In a general pregnant population, there is moderate evidence that the pooled sensitivity is 0.993 (95% CI 0.955-0.999) and specificity was 0.999 (95% CI 0.998-0.999) for the analysis of T21. Pooled sensitivity and specificity for T13 and T18 was not calculated in this population due to the low number of studies. In a high-risk pregnant population, there is moderate evidence that the pooled sensitivities for T21 and T18 are 0.998 (95% CI 0.981-0.999) and 0.977 (95% CI 0.958-0.987) respectively, and low evidence that the pooled sensitivity for T13 is 0.975 (95% CI 0.819-0.997). The pooled specificity for all three trisomies is 0.999 (95% CI 0.998-0.999).
CONCLUSIONS
This is the first meta-analysis using GRADE that shows that NIPT performs well as a screen for trisomy 21 in a general pregnant population. Although the false positive rate is low compared with first trimester combined screening, women should still be advised to confirm a positive result by invasive testing if termination of pregnancy is under consideration.
Topics: Cell-Free System; Chromosome Disorders; Chromosomes, Human, Pair 13; Chromosomes, Human, Pair 18; DNA; Down Syndrome; Female; Genetic Testing; Humans; Pregnancy; Pregnancy, High-Risk; Prenatal Diagnosis; Sensitivity and Specificity; Trisomy; Trisomy 13 Syndrome; Trisomy 18 Syndrome
PubMed: 27779757
DOI: 10.1111/aogs.13047 -
American Journal of Medical Genetics.... Sep 2016Constitutional trisomy 18 causes Edwards syndrome, which is characterized by intellectual disability and a particular set of malformations. Although this condition... (Review)
Review
Constitutional trisomy 18 causes Edwards syndrome, which is characterized by intellectual disability and a particular set of malformations. Although this condition carries high mortality during prenatal and early postnatal life, some of the rare infants who survive the first months develop benign and malignant tumors. To determine the tumor profile associated with Edwards syndrome, we performed a systematic review of the literature. This review reveals a tumor profile differing from those of Down (trisomy 21) and Patau (trisomy 13) syndromes. The literature covers 45 malignancies: 29 were liver cancers, mainly hepatoblastomas found in Japanese females; 13 were kidney tumors, predominantly nephroblastomas; 1 was neuroblastoma; 1 was a Hodgkin disease; and 1 was acute myeloid leukemia in an infant with both trisomy 18 and type 1 neurofibromatosis. No instances of the most frequent malignancies of early life-cerebral tumors, germ cell tumors, or leukemia--are reported in children with pure trisomy 18. Tumor occurrence does not appear to correlate with body weight, tissue growth, or cancer genes mapping to chromosome 18. Importantly, the most recent clinical histories report successful treatment; this raises ethical concerns about cancer treatment in infants with Edwards syndrome. In conclusion, knowledge of the Edwards' syndrome tumor profile will enable better clinical surveillance in at-risk organs (i.e., liver, kidney). This knowledge also provides clues to understanding oncogenesis, including the probably reduced frequency of some neoplasms in infants and children with this genetic condition. © 2016 Wiley Periodicals, Inc.
Topics: Carcinogenesis; Child, Preschool; Chromosomes, Human, Pair 18; Humans; Infant; Infant, Newborn; Neoplasms; Trisomy; Trisomy 18 Syndrome
PubMed: 27474103
DOI: 10.1002/ajmg.c.31511 -
BJOG : An International Journal of... Jan 2017Cell-free fetal DNA (cffDNA) non-invasive prenatal testing (NIPT) is rapidly expanding, and is being introduced at varying rates depending on country and condition. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cell-free fetal DNA (cffDNA) non-invasive prenatal testing (NIPT) is rapidly expanding, and is being introduced at varying rates depending on country and condition.
OBJECTIVES
Determine accuracy of cffDNA-based NIPT for all conditions. Evaluate influence of other factors on test performance.
SEARCH STRATEGY
Medline, Embase, CINAHL, Cochrane Library, from 1997 to April 2015.
SELECTION CRITERIA
Cohort studies reporting cffDNA-based NIPT performance in singleton pregnancies.
DATA COLLECTION AND ANALYSIS
Bivariate or univariate meta-analysis and subgroup analysis performed to explore influence of test type and population risk.
MAIN RESULTS
A total of 117 studies were included that analysed 18 conditions. Bivariate meta-analysis demonstrated sensitivities and specificities, respectively, for: fetal sex, 0.989 (95% CI 0.980-0.994) and 0.996 (95% CI 0.989-0.998), 11 179 tests; rhesus D, 0.993 (95% CI 0.982-0.997) and 0.984 (95% CI 0.964-0.993), 10 290 tests; trisomy 21, 0.994 (95% CI 0.983-0.998) and 0.999 (95% CI 0.999-1.000), 148 344 tests; trisomy 18, 0.977 (95% CI 0.952-0.989) and 0.999 (95% CI 0.998-1.000), 146 940 tests; monosomy X, 0.929 (95% CI 0.741-0.984) and 0.999 (95% CI 0.995-0.999), 6712 tests. Trisomy 13 was analysed by univariate meta-analysis, with a summary sensitivity of 0.906 (95% CI 0.823-0.958) and specificity of 1.00 (95% CI 0.999-0.100), from 134 691 tests. False and inconclusive results were poorly reported across all conditions. Although the test type affected both sensitivity and specificity, there was no evidence that population risk had any effect.
CONCLUSION
Performance of cffDNA-based NIPT is affected by condition under investigation. For fetal sex and rhesus D status, NIPT can be considered diagnostic. For trisomy 21, 18, and 13, the lower sensitivity, specificity, and disease prevalence, combined with the biological influence of confined placental mosaicism, designates it a screening test. These factors must be considered when counselling patients and assessing the cost of introduction into routine care. TWEETABLE ABSTRACT: cffDNA NIPT accuracy high, can be diagnostic for fetal sex and rhesus D, but only screening test in aneuploidy.
Topics: Biomarkers; Chromosome Disorders; DNA; Down Syndrome; Female; Humans; Predictive Value of Tests; Pregnancy; Pregnancy, High-Risk; Prenatal Diagnosis; Sensitivity and Specificity; Trisomy 13 Syndrome; Trisomy 18 Syndrome
PubMed: 27245374
DOI: 10.1111/1471-0528.14050 -
BMJ Open Jan 2016To measure test accuracy of non-invasive prenatal testing (NIPT) for Down, Edwards and Patau syndromes using cell-free fetal DNA and identify factors affecting accuracy. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To measure test accuracy of non-invasive prenatal testing (NIPT) for Down, Edwards and Patau syndromes using cell-free fetal DNA and identify factors affecting accuracy.
DESIGN
Systematic review and meta-analysis of published studies.
DATA SOURCES
PubMed, Ovid Medline, Ovid Embase and the Cochrane Library published from 1997 to 9 February 2015, followed by weekly autoalerts until 1 April 2015.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
English language journal articles describing case-control studies with ≥ 15 trisomy cases or cohort studies with ≥ 50 pregnant women who had been given NIPT and a reference standard.
RESULTS
41, 37 and 30 studies of 2012 publications retrieved were included in the review for Down, Edwards and Patau syndromes. Quality appraisal identified high risk of bias in included studies, funnel plots showed evidence of publication bias. Pooled sensitivity was 99.3% (95% CI 98.9% to 99.6%) for Down, 97.4% (95.8% to 98.4%) for Edwards, and 97.4% (86.1% to 99.6%) for Patau syndrome. The pooled specificity was 99.9% (99.9% to 100%) for all three trisomies. In 100,000 pregnancies in the general obstetric population we would expect 417, 89 and 40 cases of Downs, Edwards and Patau syndromes to be detected by NIPT, with 94, 154 and 42 false positive results. Sensitivity was lower in twin than singleton pregnancies, reduced by 9% for Down, 28% for Edwards and 22% for Patau syndrome. Pooled sensitivity was also lower in the first trimester of pregnancy, in studies in the general obstetric population, and in cohort studies with consecutive enrolment.
CONCLUSIONS
NIPT using cell-free fetal DNA has very high sensitivity and specificity for Down syndrome, with slightly lower sensitivity for Edwards and Patau syndrome. However, it is not 100% accurate and should not be used as a final diagnosis for positive cases.
TRIAL REGISTRATION NUMBER
CRD42014014947.
Topics: Biomarkers; Chromosome Disorders; Chromosomes, Human, Pair 13; Chromosomes, Human, Pair 18; DNA; Down Syndrome; Female; Humans; Pregnancy; Prenatal Diagnosis; Sensitivity and Specificity; Trisomy; Trisomy 13 Syndrome; Trisomy 18 Syndrome
PubMed: 26781507
DOI: 10.1136/bmjopen-2015-010002