Fetal fraction of cell-free DNA in noninvasive prenatal testing and adverse pregnancy outcomes: a nationwide retrospective cohort study of 56,110 pregnant women.

BACKGROUND: Noninvasive prenatal testing by cell-free DNA analysis is offered to pregnant women worldwide to screen for fetal aneuploidies. In noninvasive prenatal testing, the fetal fraction of cell-free DNA in the maternal circulation is measured as a quality control parameter. Given that fetal cell-free DNA originates from the placenta, the fetal fraction might also reflect placental health and maternal pregnancy adaptation. OBJECTIVE: This study aimed to assess the association between the fetal fraction and adverse pregnancy outcomes. STUDY DESIGN: We performed a retrospective cohort study of women with singleton pregnancies opting for noninvasive prenatal testing between June 2018 and June 2019 within the Dutch nationwide implementation study (Trial by Dutch Laboratories for Evaluation of Non-Invasive Prenatal Testing [TRIDENT]-2). Multivariable logistic regression analysis was used to assess associations between fetal fraction and adverse pregnancy outcomes. Fetal fraction was assessed as a continuous variable and as <10th percentile, corresponding to a fetal fraction <2.5%. RESULTS: The cohort comprised 56,110 pregnancies. In the analysis of fetal fraction as a continuous variable, a decrease in fetal fraction was associated with increased risk of hypertensive disorders of pregnancy (adjusted odds ratio, 2.27 [95% confidence interval, 1.89-2.78]), small for gestational age neonates <10th percentile (adjusted odds ratio, 1.37 [1.28-1.45]) and <2.3rd percentile (adjusted odds ratio, 2.63 [1.96-3.57]), and spontaneous preterm birth from 24 to 37 weeks of gestation (adjusted odds ratio, 1.02 [1.01-1.03]). No association was found for fetal congenital anomalies (adjusted odds ratio, 1.02 [1.00-1.04]), stillbirth (adjusted odds ratio, 1.02 [0.96-1.08]), or neonatal death (adjusted odds ratio, 1.02 [0.96-1.08]). Similar associations were found for adverse pregnancy outcomes when fetal fraction was <10th percentile. CONCLUSION: In early pregnancy, a low fetal fraction is associated with increased risk of adverse pregnancy outcomes. These findings can be used to expand the potential of noninvasive prenatal testing in the future, enabling the prediction of pregnancy complications and facilitating tailored pregnancy management through intensified monitoring or preventive measures.

DeltaScan for the Assessment of Acute Encephalopathy and Delirium in ICU and non-ICU Patients, a Prospective Cross-Sectional Multicenter Validation Study.

OBJECTIVES: To measure the diagnostic accuracy of DeltaScan: a portable real-time brain state monitor for identifying delirium, a manifestation of acute encephalopathy (AE) detectable by polymorphic delta activity (PDA) in single-channel electroencephalograms (EEGs). DESIGN: Prospective cross-sectional study. SETTING: Six Intensive Care Units (ICU's) and 17 non-ICU departments, including a psychiatric department across 10 Dutch hospitals. PARTICIPANTS: 494 patients, median age 75 (IQR:64-87), 53% male, 46% in ICUs, 29% delirious. MEASUREMENTS: DeltaScan recorded 4-minute EEGs, using an algorithm to select the first 96 seconds of artifact-free data for PDA detection. This algorithm was trained and calibrated on two independent datasets. METHODS: Initial validation of the algorithm for AE involved comparing its output with an expert EEG panel's visual inspection. The primary objective was to assess DeltaScan's accuracy in identifying delirium against a delirium expert panel's consensus. RESULTS: DeltaScan had a 99% success rate, rejecting 6 of the 494 EEG's due to artifacts. Performance showed and an Area Under the Receiver Operating Characteristic Curve (AUC) of 0.86 (95% CI: 0.83-0.90) for AE (sensitivity: 0.75, 95%CI=0.68-0.81, specificity: 0.87 95%CI=0.83-0.91. The AUC was 0.71 for delirium (95%CI=0.66-0.75, sensitivity: 0.61 95%CI=0.52-0.69, specificity: 72, 95%CI=0.67-0.77). Our validation aim was an NPV for delirium above 0.80 which proved to be 0.82 (95%CI: 0.77-0.86). Among 84 non-delirious psychiatric patients, DeltaScan differentiated delirium from other disorders with a 94% (95%CI: 87-98%) specificity. CONCLUSIONS: DeltaScan can diagnose AE at bedside and shows a clear relationship with clinical delirium. Further research is required to explore its role in predicting delirium-related outcomes.

First-Trimester Prediction Models Based on Maternal Characteristics for Adverse Pregnancy Outcomes: A Systematic Review and Meta-Analysis.

BACKGROUND: Early risk stratification can facilitate timely interventions for adverse pregnancy outcomes, including preeclampsia (PE), small-for-gestational-age neonates (SGA), spontaneous preterm birth (sPTB) and gestational diabetes mellitus (GDM). OBJECTIVES: To perform a systematic review and meta-analysis of first-trimester prediction models for adverse pregnancy outcomes. SEARCH STRATEGY: The PubMed database was searched until 6 June 2024. SELECTION CRITERIA: First-trimester prediction models based on maternal characteristics were included. Articles reporting on prediction models that comprised biochemical or ultrasound markers were excluded. DATA COLLECTION AND ANALYSIS: Two authors identified articles, extracted data and assessed risk of bias and applicability using PROBAST. MAIN RESULTS: A total of 77 articles were included, comprising 30 developed models for PE, 15 for SGA, 11 for sPTB and 35 for GDM. Discriminatory performance in terms of median area under the curve (AUC) of these models was 0.75 [IQR 0.69-0.78] for PE models, 0.62 [0.60-0.71] for SGA models of nulliparous women, 0.74 [0.72-0.74] for SGA models of multiparous women, 0.65 [0.61-0.67] for sPTB models of nulliparous women, 0.71 [0.68-0.74] for sPTB models of multiparous women and 0.71 [0.67-0.76] for GDM models. Internal validation was performed in 40/91 (43.9%) of the models. Model calibration was reported in 21/91 (23.1%) models. External validation was performed a total of 96 times in 45/91 (49.5%) of the models. High risk of bias was observed in 94.5% of the developed models and in 58.3% of the external validations. CONCLUSIONS: Multiple first-trimester prediction models are available, but almost all suffer from high risk of bias, and internal and external validations were often not performed. Hence, methodological quality improvement and assessment of the clinical utility are needed.

Fetal Fraction of Cell-Free DNA in the Prediction of Adverse Pregnancy Outcomes: A Nationwide Retrospective Cohort Study.

OBJECTIVE: To assess the added value of fetal fraction of cell-free DNA in the maternal circulation in the prediction of adverse pregnancy outcomes. DESIGN: Retrospective cohort study. SETTING: Nationwide implementation study on non-invasive prenatal testing (NIPT; TRIDENT-2 study). POPULATION: Pregnant women in the Netherlands opting for NIPT between June 2018 and June 2019. METHODS: Two logistic regression prediction models were constructed for each adverse pregnancy outcome. The first model (base model) included prognostic clinical parameters that were selected from existing first-trimester prediction models for adverse pregnancy outcomes. The second model (fetal fraction model) included fetal fraction as a predictor on top of the prognostic clinical parameters included in the base model. The added prognostic value of fetal fraction was assessed by comparing the base and fetal fraction models in terms of goodness of fit and predictive performance. MAIN OUTCOME MEASURES: Likelihood ratio test (LRT), area under the curve (AUC) and Integrated Discrimination Improvement (IDI) index. RESULTS: The study cohort consisted of 56 110 pregnancies. The incidence of adverse pregnancy outcomes was 5.7% for hypertensive disorders of pregnancy (HDP; n = 3207), 10.2% for birthweight < p10 (n = 5726), 3.2% for birthweight < p2.3 (n = 1796), 3.4% for spontaneous preterm birth (sPTB; n = 1891), 3.4% for diabetes (n = 1902) and 1.3% for congenital anomalies (n = 741). Adding fetal fraction to the base model improved model fit for HDP, birthweight < p10, birthweight < p2.3, all sPTB, and diabetes, but not for congenital anomalies (LRT p < 0.05). For HDP, the AUC improved from 0.67 to 0.68 by adding fetal fraction to the base model (p = 0.14) with an IDI of 0.0018 (p < 0.0001). For birthweight < p10, the AUC improved from 0.65 to 0.66 (p < 0.0001) with an IDI of 0.0023 (p < 0.0001). For birthweight < p2.3, the AUC improved from 0.67 to 0.69 (p < 0.0001) with an IDI of 0.0011 (p < 0.0001). For all sPTB, the AUC was similar for both models (AUC 0.63, p = 0.021) with an IDI of 0.00028 (p = 0.0023). For diabetes, the AUC was similar (AUC 0.72, p = 0.35) with an IDI of 0.00055 (p = 0.00015). CONCLUSIONS: Fetal fraction has statistically significant but limited prognostic value in the prediction of adverse pregnancy outcomes in addition to known prognostic clinical parameters.

Applicability of European Society of Cardiology guidelines according to gross national income.

AIMS: To assess the feasibility to comply with the recommended actions of ESC guidelines on general cardiology areas in 102 countries and assess how compliance relates to the country's income level. METHODS AND RESULTS: All recommendations from seven ESC guidelines on general cardiology areas were extracted and labelled on recommended actions. A survey was sent to all 102 ESC national and affiliated cardiac societies (NCSs). Respondents were asked to score recommended actions on their availability in clinical practice on a four-point Likert scale (fully available, mostly/often available, mostly/often unavailable, fully unavailable), and select the top three barriers perceived as being responsible for limiting their national availability. Applicability was assessed overall, per World Bank gross national income (GNI) level, and per guideline.A total of 875 guideline recommendations on general cardiology was extracted. Responses were received from 64 of 102 (62.7%) NCSs. On average, 71·6% [95% confidence interval (CI): 68.6-74.6] of the actions were fully available, 9.9% (95% CI: 8.7-11.1) mostly/often available, 6.7% (95% CI: 5.4-8.0) mostly/often unavailable, and 11·8% (95% CI: 9.5-14.1) fully unavailable. In low-income countries (LICs), substantially more actions were fully unavailable [29·4% (95% CI: 22.6-36.3)] compared with high-income countries [HICs, countries 2.4% (95% CI: 1.2-3.7); P < 0.05]. Nevertheless, a proportion of actions with the lowest availability scores were often fully or mostly unavailable independent of GNIs. Actions were most often not available due to lack of reimbursement and other financial barriers. CONCLUSION: Local implementation of ESC guidelines on general cardiology is high in HICs and low in LICs , being inversely correlated with country gross national incomes.

Prediction Models for Bronchopulmonary Dysplasia in Preterm Infants: A Systematic Review and Meta-Analysis.

OBJECTIVE: To review systematically and assess the accuracy of prediction models for bronchopulmonary dysplasia (BPD) at 36 weeks of postmenstrual age. STUDY DESIGN: Searches were conducted in MEDLINE and EMBASE. Studies published between 1990 and 2022 were included if they developed or validated a prediction model for BPD or the combined outcome death/BPD at 36 weeks in the first 14 days of life in infants born preterm. Data were extracted independently by 2 authors following the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (ie, CHARMS) and PRISMA guidelines. Risk of bias was assessed using the Prediction model Risk Of Bias ASsessment Tool (ie, PROBAST). RESULTS: Sixty-five studies were reviewed, including 158 development and 108 externally validated models. Median c-statistic of 0.84 (range 0.43-1.00) was reported at model development, and 0.77 (range 0.41-0.97) at external validation. All models were rated at high risk of bias, due to limitations in the analysis part. Meta-analysis of the validated models revealed increased c-statistics after the first week of life for both the BPD and death/BPD outcome. CONCLUSIONS: Although BPD prediction models perform satisfactorily, they were all at high risk of bias. Methodologic improvement and complete reporting are needed before they can be considered for use in clinical practice. Future research should aim to validate and update existing models.

Comparison of New Bronchopulmonary Dysplasia Definitions on Long-Term Outcomes in Preterm Infants.

OBJECTIVE: To compare the discriminative performances of the 2018 National Institutes of Health (NIH) and the 2019 Jensen definitions of bronchopulmonary dysplasia (BPD) with the 2001 NIH definition on adverse neurodevelopmental and respiratory outcomes at 2 years and 5 years corrected age. STUDY DESIGN: In this single-center retrospective cohort study, outcomes of infants born at <30 weeks of gestational age were collected. The 3 definitions of BPD were compared by adding the different definitions to the National Institute of Child Health and Human Development's outcome prediction model for neurodevelopmental impairment (NDI) or death. Discriminative performance was compared for both outcomes at 2 years and 5 years corrected age by calculating the areas under the receiver operating characteristic curve and z-statistics. RESULTS: The presence of BPD and its severity were determined in 584 infants. There were considerable shifts in BPD grading among the different definitions. At both time points, all BPD definition models had comparable discriminating power for NDI and respiratory morbidity, with one exception. Compared with the 2001 NIH definition, the 2018 NIH definition had less predictive power for the neurologic outcome at 2 years corrected age. CONCLUSIONS: Our comparison of the 3 BPD definitions shows similar discriminative performance on long term neurodevelopmental and respiratory outcomes at 2 years and 5 years corrected age.

Working conditions in women with multiple pregnancy-the impact on preterm birth and adherence to guidelines: a prospective cohort study.

BACKGROUND: Women with multiple pregnancies are at risk for maternal complications such as preterm birth. Hazardous working conditions, such as physically demanding work and long and irregular working hours, might increase the risk of preterm birth. OBJECTIVE: This study primarily aimed to determine whether certain working conditions up to 20 weeks of pregnancy increase the risk of preterm birth in multiple pregnancies. The secondary objective was to evaluate whether the working conditions of Dutch women with multiple pregnancy have been adjusted to the guidelines of the Netherlands Society of Occupational Medicine. STUDY DESIGN: We performed a prospective cohort study alongside the ProTWIN trial, a multicenter randomized controlled trial that assessed whether cervical pessaries could effectively prevent preterm birth. Women with paid work of >8 hours per week completed questionnaires concerning general health and working conditions between 16 and 20 weeks of pregnancy. Univariable and multivariable logistic regression analyses were performed to identify work-related factors associated with preterm birth (32-36 weeks' gestation) and very preterm birth (<32 weeks' gestation). We analyzed a subgroup of participants who worked for more than half of the week (>28 hours). We calculated the proportion of women who reported work-related factors not in accordance with guidelines. RESULTS: We studied 383 women, of whom 168 (44%) had been randomized to pessary, 142 (37%) to care as usual, and 73 (19%) did not participate in the randomized part of the study. After adjusting for confounding variables, working >28 hours was associated with very preterm birth (n=33; 78%) (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.1), and irregular working times were associated with preterm birth (n=26, 17%) (adjusted odds ratio, 2.0; 95% confidence interval, 1.0-4.1) and very preterm birth (n=10; 24%) (adjusted odds ratio, 2.7; 95% confidence interval, 1.0-7.3). Within a subgroup of 213 participants working >28 hours per week, multivariable analysis showed that irregular working times (n=16; 20%) (adjusted odds ratio, 3.5; 95% confidence interval, 1.2-10.1) and no/little freedom in performance of tasks (n=23; 28%) (adjusted odds ratio, 3.0; 95% confidence interval, 1.3-7.3) were associated with preterm birth. Irregular working times (n=9; 27%) (adjusted odds ratio, 3.4; 95% confidence interval, 1.0-11.1), requiring physical strength (n=9; 27%) (adjusted odds ratio, 5.3; 95% confidence interval, 1.6-17.8), high physical workload (n=7; 21%) (adjusted odds ratio, 3.9; 95% confidence interval, 1.1-13.9), and no/little freedom in performing tasks (n=10; 30%) (adjusted odds ratio, 3.2; 95% confidence interval, 1.1-9.6) were associated with very preterm birth. Before 20 weeks of pregnancy, 224 (58.5%) women with multiple pregnancy continued to work under circumstances that were not in accordance with the guidelines. CONCLUSION: In our cohort study, nearly 60% of women with multiple pregnancy continued to work under circumstances not in accordance with the guidelines to avoid physical and job strain and long and irregular working hours. Irregular hours were associated with preterm and very preterm birth, and long hours were associated with preterm birth.

Antibiotic treatment of bacterial vaginosis to prevent preterm delivery: Systematic review and individual participant data meta-analysis.

BACKGROUND: Bacterial vaginosis (BV) increases preterm delivery (PTD) risk, but treatment trials showed mixed results in preventing PTD. OBJECTIVES: Determine, using individual participant data (IPD), whether BV treatment during pregnancy reduced PTD or prolonged time-to-delivery. DATA SOURCES: Cochrane Systematic Review (2013), MEDLINE, EMBASE, journal searches, and searches (January 2013-September 2022) ("bacterial vaginosis AND pregnancy") of (i) clinicaltrials.gov; (ii) Cochrane Central Register of Controlled Trials; (iii) World Health Organization International Clinical Trials Registry Platform Portal; and (iv) Web of Science ("bacterial vaginosis"). STUDY SELECTION AND DATA EXTRACTION: Studies randomising asymptomatic pregnant individuals with BV to antibiotics or control, measuring delivery gestation. Extraction was from original data files. Bias risk was assessed using the Cochrane tool. Analysis used "one-step" logistic and Cox random effect models, adjusting gestation at randomisation and PTD history; heterogeneity by I2 . Subgroup analysis tested interactions with treatment. In sensitivity analyses, studies not providing IPD were incorporated by "multiple random-donor hot-deck" imputation, using IPD studies as donors. RESULTS: There were 121 references (96 studies) with 23 eligible trials (11,979 participants); 13 studies (6915 participants) provided IPD; 12 (6115) were incorporated. Results from 9 (4887 participants) not providing IPD were imputed. Odds ratios for PTD for metronidazole and clindamycin versus placebo were 1.00 (95% CI 0.84, 1.17), I2  = 62%, and 0.59 (95% CI 0.42, 0.82), I2  = 0 before; and 0.95 (95% CI 0.81, 1.11), I2  = 59%, and 0.90 (95% CI: 0.72, 1.12), I2  = 0, after imputation. Time-to-delivery did not differ from null with either treatment. Including imputed IPD, there was no evidence that either drug was more effective when administered earlier, or among those with a PTD history. CONCLUSIONS: Clindamycin, but not metronidazole, was beneficial in studies providing IPD, but after imputing data from missing IPD studies, treatment of BV during pregnancy did not reduce PTD, nor prolong pregnancy, in any subgroup or when started earlier in gestation.

Progestogen maintenance therapy for prolongation of pregnancy after an episode of preterm labour: A systematic review and meta-analysis.

BACKGROUND: Evidence for progestogen maintenance therapy after an episode of preterm labour (PTL) is contradictory. OBJECTIVES: To assess effectiveness of progestogen maintenance therapy after an episode of PTL. SEARCH STRATEGY: An electronic search in Central Cochrane, Ovid Embase, Ovid Medline and clinical trial databases was performed. SELECTION CRITERIA: Randomised controlled trials (RCT) investigating women between 16+0 and 37+0 weeks of gestation with an episode of PTL who were treated with progestogen maintenance therapy compared with a control group. DATA COLLECTION AND ANALYSIS: Systematic review and meta-analysis were conducted. The primary outcome was latency time in days. Secondary neonatal and maternal outcomes are consistent with the core outcome set for preterm birth studies. Studies were extensively assessed for data trustworthiness (integrity) and risk of bias. MAIN RESULTS: Thirteen RCT (1722 women) were included. Progestogen maintenance therapy demonstrated a longer latency time of 4.32 days compared with controls (mean difference [MD] 4.32, 95% CI 0.40-8.24) and neonates were born with a higher birthweight (MD 124.25 g, 95% CI 8.99-239.51). No differences were found for other perinatal outcomes. However, when analysing studies with low risk of bias only (five RCT, 591 women), a significantly longer latency time could not be shown (MD 2.44 days; 95% CI -4.55 to 9.42). CONCLUSIONS: Progestogen maintenance therapy after PTL might have a modest effect on prolongation of latency time. When analysing low risk of bias studies only, this effect was not demonstrated. Validation through further research, preferably by an individual patient data meta-analysis is highly recommended.

Association between low fetal fraction in cell-free DNA screening and fetal chromosomal aberrations: A systematic review and meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of the available literature on low fetal fraction (LFF) in cell-free DNA (cfDNA) screening and the risk of fetal chromosomal aberrations. METHOD: We searched articles published between January 2010 and May 2021 in PubMed and EMBASE databases. Risk of bias was assessed using QUADAS-2. RESULTS: Twenty-seven studies met the inclusion criteria, comprising data of 243,700 singleton pregnancies. Compared to normal fetal fraction, LFF was associated with a higher risk of trisomy 13 (OR 5.99 [3.61-9.95], I 2 of heterogeneity = 0%, n = 22 studies), trisomy 18 (OR 4.46 [3.07-6.47], I 2  = 0%, n = 22 studies), monosomy X (OR 5.88 [2.34-14.78], I 2  = 18%, n = 10 studies), and triploidy (OR 36.39 [9.83-134.68], I 2  = 61%, n = 6 studies), but not trisomy 21 (OR 1.25 [0.76-2.03], I 2  = 36%, n = 23 studies). LFF was also associated with a higher risk of various other types of fetal chromosomal aberrations (OR 4.00 [1.78-9.00], I 2  = 2%, n = 11 studies). Meta-analysis of proportions showed that absolute rates of fetal chromosomal aberrations ranged between 1% and 2% in women with LFF. A limitation of this review is the potential risk of ascertainment bias because of differences in outcome assessment between pregnancies with LFF and those with normal fetal fraction. Heterogeneity in population characteristics or applied technologies across included studies may not have been fully addressed. CONCLUSION: An LFF test result in cfDNA screening is associated with an increased risk of fetal trisomy 13, trisomy 18, monosomy X, and triploidy, but not trisomy 21. Further research is needed to assess the association between LFF and other specific types of fetal chromosomal aberrations.

Head-to-head comparison of the accuracy of saliva and nasal rapid antigen SARS-CoV-2 self-testing: cross-sectional study.

BACKGROUND: The diagnostic accuracy of unsupervised self-testing with rapid antigen diagnostic tests (Ag-RDTs) is mostly unknown. We studied the diagnostic accuracy of a self-performed SARS-CoV-2 saliva and nasal Ag-RDT in the general population. METHODS: This large cross-sectional study consecutively included unselected individuals aged ≥ 16 years presenting for SARS-CoV-2 testing at three public health service test sites. Participants underwent molecular test sampling and received two self-tests (the Hangzhou AllTest Biotech saliva self-test and the SD Biosensor nasal self-test by Roche Diagnostics) to perform themselves at home. Diagnostic accuracy of both self-tests was assessed with molecular testing as reference. RESULTS: Out of 2819 participants, 6.5% had a positive molecular test. Overall sensitivities were 46.7% (39.3-54.2%) for the saliva Ag-RDT and 68.9% (61.6-75.6%) for the nasal Ag-RDT. With a viral load cut-off (≥ 5.2 log10 SARS-CoV-2 E-gene copies/mL) as a proxy of infectiousness, these sensitivities increased to 54.9% (46.4-63.3%) and 83.9% (76.9-89.5%), respectively. For the nasal Ag-RDT, sensitivities were 78.5% (71.1-84.8%) and 22.6% (9.6-41.1%) in those symptomatic and asymptomatic at the time of sampling, which increased to 90.4% (83.8-94.9%) and 38.9% (17.3-64.3%) after applying the viral load cut-off. In those with and without prior SARS-CoV-2 infection, sensitivities were 36.8% (16.3-61.6%) and 72.7% (65.1-79.4%). Specificities were > 99% and > 99%, positive predictive values > 70% and > 90%, and negative predictive values > 95% and > 95%, for the saliva and nasal Ag-RDT, respectively, in most analyses. Most participants considered the self-performing and result interpretation (very) easy for both self-tests. CONCLUSIONS: The Hangzhou AllTest Biotech saliva self Ag-RDT is not reliable for SARS-CoV-2 detection, overall, and in all studied subgroups. The SD Biosensor nasal self Ag-RDT had high sensitivity in individuals with symptoms and in those without prior SARS-CoV-2 infection but low sensitivity in asymptomatic individuals and those with a prior SARS-CoV-2 infection which warrants further investigation.

Detection of SARS-CoV-2 infection in the general population by three prevailing rapid antigen tests: cross-sectional diagnostic accuracy study.

BACKGROUND: Rapid antigen diagnostic tests (Ag-RDTs) are the most widely used point-of-care tests for detecting SARS-CoV-2 infection. Since the accuracy may have altered by changes in SARS-CoV-2 epidemiology, indications for testing, sampling and testing procedures, and roll-out of COVID-19 vaccination, we evaluated the performance of three prevailing SARS-CoV-2 Ag-RDTs. METHODS: In this cross-sectional study, we consecutively enrolled individuals aged >16 years presenting for SARS-CoV-2 testing at three Dutch public health service COVID-19 test sites. In the first phase, participants underwent either BD-Veritor System (Becton Dickinson), PanBio (Abbott), or SD-Biosensor (Roche Diagnostics) testing with routine sampling procedures. In a subsequent phase, participants underwent SD-Biosensor testing with a less invasive sampling method (combined oropharyngeal-nasal [OP-N] swab). Diagnostic accuracies were assessed against molecular testing. RESULTS: Six thousand nine hundred fifty-five of 7005 participants (99%) with results from both an Ag-RDT and a molecular reference test were analysed. SARS-CoV-2 prevalence and overall sensitivities were 13% (188/1441) and 69% (129/188, 95% CI 62-75) for BD-Veritor, 8% (173/2056) and 69% (119/173, 61-76) for PanBio, and 12% (215/1769) and 74% (160/215, 68-80) for SD-Biosensor with routine sampling and 10% (164/1689) and 75% (123/164, 68-81) for SD-Biosensor with OP-N sampling. In those symptomatic or asymptomatic at sampling, sensitivities were 72-83% and 54-56%, respectively. Above a viral load cut-off (≥5.2 log10 SARS-CoV-2 E-gene copies/mL), sensitivities were 86% (125/146, 79-91) for BD-Veritor, 89% (108/121, 82-94) for PanBio, and 88% (160/182, 82-92) for SD-Biosensor with routine sampling and 84% (118/141, 77-89) with OP-N sampling. Specificities were >99% for all tests in most analyses. Sixty-one per cent of false-negative Ag-RDT participants returned for testing within 14 days (median: 3 days, interquartile range 3) of whom 90% tested positive. CONCLUSIONS: Overall sensitivities of three SARS-CoV-2 Ag-RDTs were 69-75%, increasing to ≥86% above a viral load cut-off. The decreased sensitivity among asymptomatic participants and high positivity rate during follow-up in false-negative Ag-RDT participants emphasise the need for education of the public about the importance of re-testing after an initial negative Ag-RDT should symptoms develop. For SD-Biosensor, the diagnostic accuracy with OP-N and deep nasopharyngeal sampling was similar; adopting the more convenient sampling method might reduce the threshold for professional testing.

When is it impractical to ask informed consent? A systematic review.

BACKGROUND: Informed consent is one of the cornerstones of biomedical research with human subjects. Research ethics committees may allow for a modification or a waiver of consent when the research has social value, involves minimal risk, and if consent is impractical to obtain. While the conditions of social value and minimal risk have received ample attention in research ethics literature, the impractical condition remains unclear. There seem to be different interpretations of the meaning of impractical within academic literature. To address this lack of clarity, we performed a systematic review on the interpretation of impractical. METHODS: First, we examined international research ethics guidelines on their usage and interpretation of impractical. Next, we used international ethical guidelines to identify synonyms of the term "impractical." Accordingly, PubMed, Embase, and Web of Science were searched for articles that included "informed consent" and "impractical" or one of its synonyms. RESULTS: We found that there were only a few international ethics guidelines that described what could be considered impractical. Out of 2329 identified academic articles, 42 were included. Impractical was used to describe four different conditions: (1) obtaining informed consent becomes too demanding for researchers, (2) obtaining informed consent leads to invalid study outcomes, (3) obtaining informed consent harms the participant, and (4) obtaining informed consent is meaningless for the participant. CONCLUSION: There are conditions that render conventional informed consent truly impractical, such as untraceable participants or harm for participants. At the same time, researchers have a moral responsibility to design an infrastructure in which consent can be obtained, even if they face hardship in obtaining consent. In addition, researchers should seek to minimize harm inflicted upon participants when harm may occur as a result of the consent procedure. Invalidity of research due to consent issues should not be regarded as impractical but as a condition that limits the social value of research. Further research is essential for when a waiver of informed consent based on impractical is also reasonable.

Development and validation of a risk prediction model of preterm birth for women with preterm labour symptoms (the QUIDS study): A prospective cohort study and individual participant data meta-analysis.

BACKGROUND: Timely interventions in women presenting with preterm labour can substantially improve health outcomes for preterm babies. However, establishing such a diagnosis is very challenging, as signs and symptoms of preterm labour are common and can be nonspecific. We aimed to develop and externally validate a risk prediction model using concentration of vaginal fluid fetal fibronectin (quantitative fFN), in combination with clinical risk factors, for the prediction of spontaneous preterm birth and assessed its cost-effectiveness. METHODS AND FINDINGS: Pregnant women included in the analyses were 22+0 to 34+6 weeks gestation with signs and symptoms of preterm labour. The primary outcome was spontaneous preterm birth within 7 days of quantitative fFN test. The risk prediction model was developed and internally validated in an individual participant data (IPD) meta-analysis of 5 European prospective cohort studies (2009 to 2016; 1,783 women; mean age 29.7 years; median BMI 24.8 kg/m2; 67.6% White; 11.7% smokers; 51.8% nulliparous; 10.4% with multiple pregnancy; 139 [7.8%] with spontaneous preterm birth within 7 days). The model was then externally validated in a prospective cohort study in 26 United Kingdom centres (2016 to 2018; 2,924 women; mean age 28.2 years; median BMI 25.4 kg/m2; 88.2% White; 21% smokers; 35.2% nulliparous; 3.5% with multiple pregnancy; 85 [2.9%] with spontaneous preterm birth within 7 days). The developed risk prediction model for spontaneous preterm birth within 7 days included quantitative fFN, current smoking, not White ethnicity, nulliparity, and multiple pregnancy. After internal validation, the optimism adjusted area under the curve was 0.89 (95% CI 0.86 to 0.92), and the optimism adjusted Nagelkerke R2 was 35% (95% CI 33% to 37%). On external validation in the prospective UK cohort population, the area under the curve was 0.89 (95% CI 0.84 to 0.94), and Nagelkerke R2 of 36% (95% CI: 34% to 38%). Recalibration of the model's intercept was required to ensure overall calibration-in-the-large. A calibration curve suggested close agreement between predicted and observed risks in the range of predictions 0% to 10%, but some miscalibration (underprediction) at higher risks (slope 1.24 (95% CI 1.23 to 1.26)). Despite any miscalibration, the net benefit of the model was higher than "treat all" or "treat none" strategies for thresholds up to about 15% risk. The economic analysis found the prognostic model was cost effective, compared to using qualitative fFN, at a threshold for hospital admission and treatment of ≥2% risk of preterm birth within 7 days. Study limitations include the limited number of participants who are not White and levels of missing data for certain variables in the development dataset. CONCLUSIONS: In this study, we found that a risk prediction model including vaginal fFN concentration and clinical risk factors showed promising performance in the prediction of spontaneous preterm birth within 7 days of test and has potential to inform management decisions for women with threatened preterm labour. Further evaluation of the risk prediction model in clinical practice is required to determine whether the risk prediction model improves clinical outcomes if used in practice. TRIAL REGISTRATION: The study was approved by the West of Scotland Research Ethics Committee (16/WS/0068). The study was registered with ISRCTN Registry (ISRCTN 41598423) and NIHR Portfolio (CPMS: 31277).

Placenta Pathology From Term Born Neonates With Normal or Adverse Outcome.

BACKGROUND: The incidence of umbilical cord or placental parenchyma abnormalities associated with mortality or morbidity of term infants is lacking. METHODS: Placentas of 55 antepartum stillbirths (APD), 21 intrapartum stillbirths (IPD), 12 neonatal deaths (ND), and 80 admissions to a level 3 neonatal intensive care unit (NS) were studied and compared with 439 placentas from neonates from normal term pregnancies and normal outcome after vaginal delivery (NPVD) and with 105 placentas after an elective caesarian sections (NPEC). RESULTS: NPVD and NPEC placentas showed no or one abnormality in 70% and placentas from stillbirth showed two or more abnormalities in 80% of cases. APD placentas more frequently had a low weight and less formation of terminal villi. Hypercoiling was more often present in all study groups. Severe chronic villitis was almost exclusively present in APD placentas. Chorioamnionitis was significantly more frequent in APD, IPD and NS placentas and funisitis was more often observed in IPD and NS placentas. CONCLUSION: Multiple placental abnormalities are significantly more frequent in placentas from term neonates with severe perinatal morbidity and mortality. These placental abnormalities are thought to be associated with disturbed oxygen transfer or with inflammation.

Timing of recurrence after surgery in pelvic organ prolapse.

OBJECTIVES: The aim of this study was to determine when women are at risk for recurrent pelvic organ prolapse (POP). METHODS: From 2010 to 2018, all women with symptomatic prolapse, Pelvic Organ Prolapse Quantification (pop-Q) stage 2 in at least one compartment and prolapse surgery were included. The primary outcome measure was POP recurrence. Kaplan-Meier estimates were calculated, survival curves were created, and differences in survival curves were tested with log-rank test. Cox proportional hazard regression was used to investigate associations between recurrence and the number and type of involved compartment(s) and type of surgery. RESULTS: Forty-six (16.8%) out of 274 patients had POP recurrence during a mean follow-up time of 55 ± 32 months. The mean age was 64 ± 12 years. The hazard of recurrence increased the most in the first 2 years after POP surgery, flattened in years 3 and 4 and remained almost stable in the years thereafter, regardless of the site and number of involved compartment(s). The hazard of recurrence over time seemed the largest when all three compartments were involved. However, there was no statistically significant difference in recurrence between the numbers of (p = 0.65) or in the combination of involved compartments (p = 0.19). There was no difference in POP recurrence over time between prolapse repair with either sacrospinous ligament fixation or vaginal hysterectomy (p = 0.48). CONCLUSIONS: Women are at the highest risk of POP recurrence in the first 2 years after POP surgery independent of the number or combination of involved compartment(s).

Pharmacotherapy for smoking cessation: effects by subgroup defined by genetically informed biomarkers.

This review has been withdrawn because it has been found to be in breach of the Cochrane Commercial Sponsorship policy clause 2:  'Individuals who are currently employed or where employed any time in the last three years by a company that has a real or potential financial interest in the outcome of the review (including but not limited to drug companies or medical device manufacturers); or who hold or have applied for a patent related to the review are prohibited from being Cochrane Review authors. In most cases, current or previous employment would be characterized by the affiliation statement made by the author at the title registration, protocol, or review stage of the review'.

Smoking Cessation Pharmacotherapy Based on Genetically-Informed Biomarkers: What is the Evidence?

INTRODUCTION: Pharmacogenomic studies have used genetic variants to identify smokers likely to respond to pharmacological treatments for smoking cessation. METHODS: We performed a systematic review and meta-analysis of primary and secondary analyses of trials of smoking cessation pharmacotherapies. Eligible were trials with data on a priori selected single nucleotide polymorphisms, replicated non-single nucleotide polymorphisms, and/or the nicotine metabolite ratio. We estimated the genotype × treatment interaction as the ratio of risk ratios (RRR) for treatment effects across genotype groups. RESULTS: We identified 18 trials (N = 9017 participants), including 40 active (bupropion, nicotine replacement therapy [NRT], varenicline, or combination therapies) versus placebo comparisons and 16 active versus active comparisons. There was statistical evidence of heterogeneity across rs16969968 genotypes in CHRNA5 with regard to both 6-month abstinence and end-of-treatment abstinence in non-Hispanic black smokers and end-of-treatment abstinence in non-Hispanic white smokers. There was also heterogeneity across rs1051730 genotypes in CHRNA3 with regard to end-of-treatment abstinence in non-Hispanic white smokers. There was no clear statistical evidence for other genotype-by-treatment combinations. Compared with placebo, NRT was more effective among non-Hispanic black smokers with rs16969968-GG with regard to both 6-month abstinence (RRR for GG vs. GA or AA, 3.51; 95% confidence interval [CI] = 1.19 to 10.30) and end-of-treatment abstinence (RRR for GG vs. GA or AA, 5.84; 95% CI = 1.89 to 18.10). Among non-Hispanic white smokers, NRT effectiveness relative to placebo was comparable across rs1051730 and rs169969960 genotypes. CONCLUSIONS: We did not identify widespread differential effects of smoking cessation pharmacotherapies based on genotype. The quality of the evidence is generally moderate. IMPLICATIONS: Although we identified some evidence of genotype × treatment interactions, the vast majority of analyses did not provide evidence of differential treatment response by genotype. Where we find some evidence, these results should be considered preliminary and interpreted with caution because of the small number of contributing trials per genotype comparison, the wide confidence intervals, and the moderate quality of evidence. Prospective trials and individual-patient data meta-analyses accounting for heterogeneity of treatment effects through modeling are needed to assess the clinical utility of genetically informed biomarkers to guide pharmacotherapy choice for smoking cessation.

Child outcomes after placement of a cervical pessary in women with a multiple pregnancy: A 4-year follow-up of the ProTWIN trial.

INTRODUCTION: The ProTWIN trial previously showed no beneficial effect of treatment with a cervical pessary vs usual care to prevent preterm birth in women with a multiple pregnancy. However, in women with a midtrimester short cervix (<38 mm), pessary did reduce the composite outcome of neonatal morbidity and mortality. This follow-up study evaluates the long-term outcomes of all children born to mothers who participated in the ProTWIN trial at 4 years of age. MATERIAL AND METHODS: Parents received the Ages and Stages Questionnaire, Strength and Difficulties Questionnaire and a health questionnaire. All questionnaires were reported separately and as a combined outcome (abnormal child outcome). A linear mixed effects model was used to adjust for correlated data in twins and correction for confounders was performed. In exploratory analysis, a composite outcome of death or survival with abnormal child outcome was used by combining extrapolated data on child outcome with survival data. All data were analyzed for the total group and the subgroup of women with midtrimester short cervix. RESULTS: Of the original 813 women of the ProTWIN trial, we approached 579, of whom 258 participated (45%) in follow-up. We received questionnaires of 514 children (281 pessary vs 233 control), with 119 children in the subgroup of women with midtrimester short cervix. An abnormal child outcome was found in 23% in the pessary group vs 16% in the control group (odds ratio 1.58; 95% confidence interval 0.94-2.65). In exploratory analysis with extrapolated data on child outcome (n = 815), no difference in abnormal child outcome was seen between the pessary and control group. In the subgroup of women with a short cervix (n = 268), this composite outcome indicated a favorable outcome for children born to mothers with pessary. CONCLUSIONS: In women with a multiple pregnancy, the use of a cervical pessary did not improve development, behavior or physical outcomes of the surviving children at age 4.