9 research outputs found
Electron transfer reactions in sub-porphyrin-naphthyldiimide dyads
A series of donor-acceptor compounds based on a sub-porphyrin (SubP) as an electron donor and naphthyldiimide (NDI) as an acceptor has been designed, synthesized and investigated by time-resolved emission and transient absorption measurements. The donor and acceptor are separated by a single phenyl spacer substituted by methyl groups in order to systematically vary the electronic coupling. The electron transfer reactions in toluene are found to be quite fast; charge separation is quantitative and occurs within 5-10 ps and charge recombination occurs in 1-10 ns, depending on the substitution pattern. As expected, when steric bulk is introduced on the adjoining phenyl group, electron transfer rates slow down because of smaller electronic coupling. Quantum mechanical modelling of the potential energy for twisting the dihedral angles combined with a simplified model of the electronic coupling semi-quantitatively explains the observed variation of the electron transfer rates. Investigating the temperature variation of the charge separation in 2-methyltetrahydrofuran (2-MTHF) and analyzing using the Marcus model allow experimental estimation of the electronic coupling and reorganization energies. At low temperature, relatively strong phosphorescence is observed from the donor-acceptor compounds with onset at 660 nm signaling that charge recombination occurs, at least partially, through the sub-porphyrin localized triplet excited state. Finally, it is noted that charge separation in all SubP-NDI dyads is efficient even at cryogenic temperatures (85 K) in 2-MTHF glass
Additional value of advanced ultrasonography in pregnancies with two inconclusive cell-free DNA draws
Objective: We aimed to evaluate the additional value of advanced fetal anatomical assessment by ultrasound in pregnancies with twice inconclusive noninvasive testing (NIPT) due to low fetal fraction (FF). Methods: We performed a multicenter-retrospective study between 2017 and 2020 including 311 pregnancies with twice inconclusive NIPT due to low FF â€Â 1%. Women were offered invasive testing and advanced fetal anatomical assessment at â€18 weeks' gestation. Ultrasound findings, genetic testing, and pregnancy/postnatal outcomes were evaluated. Results: Ninety-two/311 (29.6%) women underwent invasive testing. Structural anomalies were diagnosed in 13/311 (4.2%) pregnancies (nine at the first scan and four at follow-up). In 6/13 (46.2%) cases, genetic aberrations were confirmed (one case of Trisomy 13 (detectable by NIPT), two of Triploidy, one of 16q12-deletion, HCN4-mutation and UPD(16) (nondetectable by NIPT). Genetic aberrations were found in 4/298 (1.3%) structurallynormal pregnancies (one 47XYY, two microscopic aberrations, one monogenic disorder found postpartum). Structural anomalies in genetically normal fetuses (2.0%) were not more prevalent compared to the general pregnant population (OR 1.0 [0.4â2.2]). Conclusion: In pregnancies with twice inconclusive NIPT due to low FF, fetal structural anomalies are not more prevalent than in the general obstetric population. The detailed anatomical assessment has the added value to detect phenotypical features suggestive of chromosomal/genetic aberrations and identify pregnancies where advanced genetic testing may be indicated
Prenatal detection of aortic coarctation in a well-organized screening setting: Are we there yet?
OBJECTIVE: We aimed to assess current prenatal detection rate (DR) of aortic coarctation (CoA) and its impact on neonatal outcome in the Netherlands to evaluate the efficacy of the Dutch screening protocol in which the cardiac four-chamber view, outflow tracts and three-vessel view are compulsory. METHODS: All prenatally and postnatally diagnosed CoA cases between 2012 and 2021 were extracted from our PRECOR-registry. Annual DRs were calculated with a focus on the trend over time and attributing factors for detection. Postnatal outcome was compared between prenatally detected and undetected cases. RESULTS: 49/116 cases (42.2%) were detected prenatally. A higher chance of detection was found for cases with extracardiac malformations (71.4%; p = 0.001) and the more severe cases with an aortic arch hypoplasia and/or ventricular septal defect (63.2%; p = 0.001). Time-trend analysis showed no improvement in DR over time (p = 0.33). Undetected cases presented with acute circulatory shock in 20.9% and were more likely to have severe lactic acidosis (p = 0.02) and impaired cardiac function (p < 0.001) before surgery. CONCLUSION: Even in a well-organized screening program, the DR of CoA still requires improvement, especially in isolated cases. The increased risk of severe lactic acidosis in undetected cases stresses the need for urgent additions to the current screening program, such as implementation of the three-vessel trachea view and measurement of outflow tracts
Factors Related to Fetal Demise in cases with Congenital Heart Defects
BACKGROUND: Congenital heart defects (CHD) are the most common congenital anomaly. Despite the increasing survival of these children, there is still an increased incidence of fetal demise, frequently attributed to cardiac failure. As abnormal placental development has been described in CHD, our hypothesis is that placenta insufficiency may contribute to fetal death in CHD. OBJECTIVES: The aim of this study is to assess cases with fetal CHD and intra uterine demise, and analyze factors that are related to the demise. STUDY DESIGN: All CHD cases diagnosed prenatally in the period January 2002- January 2021 were selected from the regional prospective CHD registry PRECOR. Multiple pregnancies and pregnancies with fetal trisomy 13/18, triploidy and Turner's syndrome were excluded from the analysis, as fetal demise is attributed to the chromosomal abnormality in these cases. Cases were categorized into four groups based on the possible cause of fetal death: cardiac failure, additional (genetic) diagnosis, placental insufficiency and a group in which no cause was found. A separate analysis was performed for isolated CHD cases. RESULTS: Of the 4806 cases in the PRECOR registry, 112 had fetal demise, of which 43 were excluded from the analysis (13 multiple pregnancies, 30 genetic). Of these, 47.8% were most likely related to cardiac failure, 42.0% to another (genetic) diagnosis and 10.1% to placental insufficiency. No cases were allocated to the group with an unknown cause. Only 47.8% of the cases had isolated CHD and in this group 21.2% was most likely related to placental insufficiency. CONCLUSIONS: This study shows that in addition to cardiac failure and other (genetic) diagnoses, placental factors play an important role in fetal demise in CHD, especially in cases of isolated heart defects. Thus, these findings support the importance of regular ultrasonographic assessment of fetal growth and placental function in fetal CHD
Increased nuchal translucency before 11 weeks of gestation: Reason for referral?
Objectives: In this era of non-invasive-prenatal testing (NIPT), when dating scans are usually performed around 10 weeks of gestation, an increased NT before the official established timeframe (CRL between 45 and 84 mm) may be encountered. Information on management of these pregnancies is limited. Therefore, we evaluated the relationship between an early increased NT and adverse pregnancy outcome. Secondary, we evaluated the rate of chromosomal anomalies that might have been missed in first trimester should solely NIPT be performed as first-tier test, and the rate of adverse pregnancy outcome if NT normalizes before 14 weeks. Methods: We performed a retrospective cohort study that included all pregnancies between January 1, 2007 and June 1, 2020 in Amsterdam UMC locations AMC and VUmc. We included fetuses with a crown-rump length (CRL) < 45 mm (âŒ11 weeks) and a nuchal translucency (NT) measurement â„2.5 mm. Fetuses referred with an early increased NT and a major fetal anomaly at the dating scan were excluded, as were cases of parents with a family history of monogenetic disease(s) or recognized carriers of a balanced translocation. Results: We included 120 fetuses of which 66.7% (80/120) had an adverse pregnancy outcome. Congenital anomalies were present in 56.7% (68/120), 45.8% (55/120) had a chromosomal anomaly. The prevalence of congenital anomalies was 30.3% in fetuses with NT 2.5â3.4 mm compared to 66.7% with NT â„ 3.5 mm (p < 0.001). 16.7% (20/120) had a chromosomal anomaly that might have been missed by conventional NIPT in first trimester. We found an adverse pregnancy outcome of 24% in the group with a normalized NT compared to 78.1% in the group with a persistently increased NT (p < 0.001). Conclusion: An early increased NT should make the sonographer alert. In this selected cohort, an early increased NT was associated with a high probability of having an adverse pregnancy outcome. Regardless of CRL, we deem that an early increased NT â„ 3.5 mm warrants referral to a Fetal Medicine Unit for an extensive work-up. NT normalization seems favorable, but a prospective study should define the appropriate work-up for NT in the lower range (2.5â3.4 mm)
Short-term outcome after the prenatal diagnosis of right aortic arch
Objectives: To determine the proportion of children that require surgery in the first year of life and thereafter in order to improve the counseling of parents with a fetus with a right aortic arch (RAA). Methods: Fetuses diagnosed with isolated RAA, defined as the absence of intra- or extracardiac anomalies, between 2007 and 2021 were extracted from the prospective registry PRECOR. Results: In total, 110 fetuses were included, 92 with a prenatal diagnosis of RAA and 18 with double aortic arch (DAA). The prevalence of 22q11 deletion syndrome was 5.5%. Six pregnancies were terminated and five cases were false-positive; therefore, the follow-up consisted of 99 neonates. Surgery was performed in 10 infants (10%) in the first year of life. In total, 25 (25%) children had surgery at a mean age of 17Â months. Eight of these 25 (32%) had a DAA. Only one child, with a DAA, required surgery in the first week of life due to obstructive stridor. Conclusions: Children with a prenatally diagnosed RAA are at a low risk of acute respiratory postnatal problems. Delivery in a hospital with neonatal intensive care and pediatric cardiothoracic facilities seems only indicated in cases with suspected DAA. Expectant parents should be informed that presently 25% of the children need elective surgery and only incidentally due to acute respiratory distress
Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations
Background: Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. Objectives: To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeksâ gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeksâ gestation. Search methods: We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. Selection criteria: Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeksâ gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. Data collection and analysis: Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. Main results: Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. Authors' conclusions: A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeksâ gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeksâ gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeksâ gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.</p
Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations
Background: Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. Objectives: To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeksâ gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeksâ gestation. Search methods: We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. Selection criteria: Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeksâ gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. Data collection and analysis: Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. Main results: Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. Authors' conclusions: A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeksâ gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeksâ gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeksâ gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.</p
Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF
BACKGROUND: Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes