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OBJECTIVES: Investigations about cesarean delivery (CD) on maternal request (CDMR) and infant infection risk frequently rely on administrative data with poorly defined indications for CD. We sought to determine the association between CDMR and infant infection using an intent-to-treat approach. METHODS: This was a population-based cohort study of low-risk singleton pregnancies with a term live birth in Ontario, Canada between April 2012 and March 2018. Subjects with prior CD were excluded. Outcomes included upper and lower respiratory tract infections, gastrointestinal infections, otitis media, and a composite of these 4. Relative risk and 95% CI were calculated for component and composite outcomes up to 1 year following planned CDMR versus planned vaginal deliveries (VDs). Subgroup and sensitivity analyses included age at infection (≤28 vs. >28 days), type of care (ambulatory vs. hospitalisation), restricting the cohort to nulliparous pregnancies, and including individuals with previous CD. Last, we re-examined outcome risk on an as-treated basis (actual CD vs. actual VD). RESULTS: Of 422 134 pregnancies, 0.4% (1827) resulted in a planned CDMR. After adjusting for covariates, planned CDMR was not associated with a risk of composite infant infections (adjusted relative risk 1.02; 95% CI 0.92-1.11). Findings for component infection outcomes, subgroup, and sensitivity analyses were similar. However, the as-treated analysis of the role of delivery mode on infant risk for infection demonstrated that actual CD (planned and unplanned) was associated with an increased risk for infant infections compared to actual VD. CONCLUSIONS: Planned CDMR is not associated with increased risk for neonatal or infant infections compared with planned VD. Study design must be carefully considered when investigating the impact of CDMR on infant infection outcomes.
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Cesárea , Humanos , Feminino , Cesárea/estatística & dados numéricos , Gravidez , Ontário/epidemiologia , Adulto , Recém-Nascido , Estudos de Coortes , Infecções Respiratórias/epidemiologia , Procedimentos Cirúrgicos Eletivos/estatística & dados numéricos , Otite Média/epidemiologiaRESUMO
OBJECTIVE: The impact of gestational weight loss (GWL) on fetal growth among women with obesity remains unclear. This study aimed to examine the association between weight loss during pregnancy among women with body mass index (BMI) ≥ 30 kg/m2 and the risk of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) neonates. METHODS: We conducted a retrospective, population-based cohort study of women with pre-pregnancy obesity that resulted in a singleton live birth in 2012-2017, using birth registry data in Ontario, Canada. Women with pregnancy complications or health conditions which could cause weight loss were excluded. GWL is defined as negative gestational weight change (≤0 kg). The association between GWL and fetal growth was estimated using generalized estimating equation models and restricted cubic spline regression analysis. Stratified analysis was conducted by obesity class (I:30-34.9 kg/m2, II:35-39.9 kg/m2, and III + : ≥40 kg/m2). RESULTS: Of the 52,153 eligible women who entered pregnancy with a BMI ≥ 30 kg/m2, 5.3% had GWL. Compared to adequate gestational weight gain, GWL was associated with an increased risk of SGA neonates (aRR:1.45, 95% CI: 1.30-1.60) and a decreased risk of LGA neonates (aRR: 0.81, 95% CI:0.73-0.93). Non-linear L-shaped associations were observed between gestational weight change and SGA neonates, with an increased risk of SGA observed with increased GWL. On the contrary, non-linear S-shaped associations were observed between gestational weight change and LGA neonates, with a decreased risk of LGA observed with increased GWL. Similar findings were observed from the stratified analysis by obesity class. CONCLUSION: These findings highlight that GWL in women with obesity may increase the risk of SGA neonates but reduce the risk of LGA neonates. Recommendations of GWL for women with obesity should be interpreted with caution.
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Obesidade , Aumento de Peso , Gravidez , Recém-Nascido , Feminino , Humanos , Estudos Retrospectivos , Estudos de Coortes , Obesidade/complicações , Obesidade/epidemiologia , Recém-Nascido Pequeno para a Idade Gestacional , Desenvolvimento Fetal , Redução de Peso , Retardo do Crescimento Fetal , Ontário/epidemiologia , Índice de Massa Corporal , Peso ao Nascer , Resultado da Gravidez/epidemiologiaRESUMO
BACKGROUND: Due to heightened occupational stress throughout the COVID-19 pandemic, hospital nurses have experienced high rates of depression, anxiety, and burnout. Nurses in obstetrical departments faced unique challenges, such as the management of COVID-19 infection in pregnancy with limited evidence-based protocols and the unknown risks of the virus on pregnancy and fetal development. Despite evidence that obstetrical nurses have experienced high levels of job stress and a decrease in job satisfaction during the COVID-19 pandemic, there is less known about the working conditions resulting in these changes. Using the Job Demands-Resources (JD-R) model, this study aims to offer insight into the COVID-19 working environment of obstetrical nurses and shed light on their COVID-19 working experiences. METHODS: The study was conducted using a qualitative approach, with data collection occurring through semi-structured interviews from December 2021 to June 2022. A total of 20 obstetrical nurses recruited from the obstetrical departments of a tertiary hospital located in Ontario, Canada, participated in the study. Interviews were audio-recorded, transcribed verbatim, and coded using NVivo. Data was analyzed using a theoretical thematic approach based on the JD-R model. RESULTS: Four themes were identified: (1) Job stressors, (2) Consequences of working during COVID-19, (3) Personal resources, and (4) Constructive feedback surrounding job resources. The findings show that obstetrical nurses faced several unique job stressors during the COVID-19 pandemic but were often left feeling inadequately supported and undervalued by hospital upper management. However, participants offered several suggestions on how they believe support could have been improved and shared insight on resources they personally used to cope with job stress during the pandemic. A model was created to demonstrate the clear linkage between the four main themes. CONCLUSIONS: This qualitative study can help inform hospital management and public policy on how to better support and meet the needs of nurses working in obstetrical care during pandemics. Moreover, applying the JD-R model offers both a novel and comprehensive look at how the COVID-19 hospital work environment has influenced obstetrical nurses' well-being and performance.
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BACKGROUND: COVID-19 vaccines are recommended for pregnant and lactating individuals, and there is substantial evidence for their safety and effectiveness. As the pandemic continues, information on worries and beliefs surrounding perinatal COVID-19 vaccination remains important to inform efforts aimed at improving vaccine uptake. Our objectives were to assess factors associated with COVID-19 vaccination among perinatal individuals; and to explore motivational factors associated with willingness to be vaccinated among unvaccinated perinatal individuals. METHODS: This was a cross-sectional web-based survey of preconception, pregnant, and lactating individuals in Canada. The outcomes of interest were vaccination with at least one dose of any COVID-19 vaccine and willingness to be vaccinated among unvaccinated individuals. Sample characteristics were summarized using frequencies and percentages. The association between eight prespecified risk factors and two outcomes (vaccination status and willingness to be vaccinated) was assessed by logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for the total sample, and across perinatal sub-groups. RESULTS: Among 3446 survey respondents, there were 447 (13.0%) preconception, 1832 (53.2%) pregnant, and 1167 (42.4%) lactating. There were 1460 (42.4%) and 1982 (57.5%) who were vaccinated and unvaccinated, respectively. Factors positively associated with COVID-19 vaccine status were speaking to a healthcare provider about vaccination during the perinatal period (aOR:2.35, 95% CI:1.97-2.80) and believing that the COVID-19 vaccine is effective (aOR:1.91, 95% CI:1.46-2.48). Factors negatively associated with vaccine status included worries about fetal growth and development (aOR:0.55, 95% CI:0.43-0.70) and future child behavioral/neurodevelopmental problems (aOR:0.59, 95% CI:0.46-0.75). Among unvaccinated individuals specifically, characteristics positively associated with willingness to vaccinate were speaking to a healthcare provider (aOR:1.67, 95% CI:1.32-2.12) and believing the COVID-19 vaccine is effective (aOR:3.56, 95% CI:2.70-4.69). Factors negatively associated with willingness were concerns over infertility (aOR:0.66, 95% CI:0.49-0.88), fetal growth and development (aOR:0.33, 95% CI:0.24-0.46), and future child behavioral/neurodevelopmental problems (aOR:0.64, 95% CI:0.48-0.84). CONCLUSIONS: In this Canadian perinatal population, approximately 42% reported COVID-19 vaccination. Among unvaccinated individuals, willingness to receive vaccination was high (73%). Factors enhancing vaccine willingness included discussions with healthcare providers and believing the vaccine was effective. Concerns regarding vaccine safety, particularly with respect to fetal/child development, were the greatest barriers to vaccine uptake.
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Vacinas contra COVID-19 , COVID-19 , Criança , Feminino , Gravidez , Humanos , Estudos Transversais , Lactação , COVID-19/epidemiologia , COVID-19/prevenção & controle , Canadá/epidemiologia , VacinaçãoRESUMO
OBJECTIVE: Obstetrical patients are at risk of complications from COVID-19 and face increased stress due to the pandemic and changes in hospital birth setting. The objective was to describe the perinatal care experiences of obstetrical patients who gave birth during the early phases of the COVID-19 pandemic. METHODS: A descriptive epidemiological survey was administered to consenting patients who gave birth at The Ottawa Hospital (TOH) between March 16th and June 16th, 2020. The participants reported on prenatal, in-hospital, and postpartum care experiences. COVID-19 pandemic related household stress factors were investigated. Frequencies and percentages are presented for categorical variables and median and interquartile range (IQR) for continuous variables. RESULTS: A total of 216 participants were included in the analyses. Median participants age was 33 years (IQR: 30-36). Collectively, 94 (43.5%) participants felt elevated stress for prenatal appointments and 105 (48.6%) for postpartum appointments because of COVID-19. There were 108 (50.0%) were scared to go to the hospital for delivery, 97 (44.9%) wore a mask during labour and 54 (25.0%) gave birth without a support person. During postpartum care, 125 (57.9%) had phone appointments (not offered prior to COVID-19), and 18 (8.3%) received no postpartum care at all. CONCLUSION: COVID-19 pandemic and public health protocols created a stressful healthcare environment for the obstetrical population where many were fearful of accessing services, experienced changes to standard care, or no care at all. As the pandemic continues, careful attention should be given to the perinatal population to reduce stress and improve continuity of care.
RéSUMé: OBJECTIF: Les patients obstétriques sont à risque de complications de la COVID-19 et font face à un stress accru en raison de la pandémie et des changements dans le cadre de l'accouchement en milieu hospitalier. L'objectif était de décrire les expériences de soins périnataux des patients obstétriques qui ont accouché au cours des premières phases de la pandémie de COVID-19. MéTHODES: Un sondage épidémiologique descriptif a été menée auprès de patients qui ont accouché à L'Hôpital d'Ottawa (TOH) entre le 16 mars et le 16 juin 2020. Les participants ont fait un compte rendu de leurs expériences en matière de soins prénataux, hospitaliers et post-partum. Les facteurs de stress domestique liés à la COVID-19 ont été étudiés. Les fréquences et les pourcentages sont présentés pour les variables catégorielles et la médiane et l'écart interquartile (IQR) sont présentés pour les variables continues. RéSULTATS: Au total, 261 participants ont répondu au sondage. L'âge maternel médian était de 33 ans (IQR: 3036). Collectivement, 94 participants (43,5%) ressentaient un stress élevé en lien avec les rendez-vous prénataux et 105 (48,6%) pour les rendez-vous post-partum en raison de la COVID-19. Il y avait 108 patients (50,0%) qui avaient peur d'aller à l'hôpital pour accoucher, 97 (44,9%) qui portaient un masque pendant leur travail et 54 (25,0%) qui ont accouché sans personne de soutien. En lien avec les soins post-partum, 125 (57,9%) ont eu des rendez-vous téléphoniques (non offerts avant la pandémie COVID-19) et 18 (8,3%) n'ont reçu aucun soin post-partum. CONCLUSION: La pandémie de COVID-19 et les politiques de santé publique ont créé un environnement de soins de santé stressant pour la population obstétrique où beaucoup avaient peur d'accéder aux services de soins, ont connu des changements dans les soins de base ou n'ont pas eu de soins du tout. Alors que la pandémie se poursuit, une attention particulière doit être accordée à la population périnatale afin de réduire le stress et améliorer la continuité des soins.
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COVID-19 , Adulto , COVID-19/epidemiologia , Feminino , Humanos , Pandemias , Parto , Avaliação de Resultados da Assistência ao Paciente , Período Pós-Parto , GravidezRESUMO
OBJECTIVES: The establishment of cut-offs for normal amniotic fluid volume (AFV) is valuable to predict perinatal outcomes. However, the most common methods to measure AFV are not accurate enough. It is important to understand factors that may be able to increase the accuracy of the calculation of AFV cut-off values. The objective of this study was to verify the correlation between AFV and estimated fetal weight (EFW). METHODS: Records from almost 7,000 patients between 2012 and 2017 were accessed through hospital databases. The AFV measurements included in our analysis were obtained using the maximum vertical pocket technique. RESULTS: AFV was positively correlated with EFW in the overall, male and female samples; however, the magnitude of the association was small (0.1Assuntos
Líquido Amniótico
, Peso Fetal
, Líquido Amniótico/diagnóstico por imagem
, Feminino
, Idade Gestacional
, Humanos
, Masculino
, Gravidez
, Gestantes
, Cuidado Pré-Natal
, Ultrassonografia Pré-Natal
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Deep neural networks have been widely adopted in numerous domains due to their high performance and accessibility to developers and application-specific end-users. Fundamental to image-based applications is the development of Convolutional Neural Networks (CNNs), which possess the ability to automatically extract features from data. However, comprehending these complex models and their learned representations, which typically comprise millions of parameters and numerous layers, remains a challenge for both developers and end-users. This challenge arises due to the absence of interpretable and transparent tools to make sense of black-box models. There exists a growing body of Explainable Artificial Intelligence (XAI) literature, including a collection of methods denoted Class Activation Maps (CAMs), that seek to demystify what representations the model learns from the data, how it informs a given prediction, and why it, at times, performs poorly in certain tasks. We propose a novel XAI visualization method denoted CAManim that seeks to simultaneously broaden and focus end-user understanding of CNN predictions by animating the CAM-based network activation maps through all layers, effectively depicting from end-to-end how a model progressively arrives at the final layer activation. Herein, we demonstrate that CAManim works with any CAM-based method and various CNN architectures. Beyond qualitative model assessments, we additionally propose a novel quantitative assessment that expands upon the Remove and Debias (ROAD) metric, pairing the qualitative end-to-end network visual explanations assessment with our novel quantitative "yellow brick ROAD" assessment (ybROAD). This builds upon prior research to address the increasing demand for interpretable, robust, and transparent model assessment methodology, ultimately improving an end-user's trust in a given model's predictions. Examples and source code can be found at: https://omni-ml.github.io/pytorch-grad-cam-anim/.
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Redes Neurais de Computação , Inteligência Artificial , Humanos , Algoritmos , Aprendizado ProfundoRESUMO
Deep learning algorithms have demonstrated remarkable potential in clinical diagnostics, particularly in the field of medical imaging. In this study, we investigated the application of deep learning models in early detection of fetal kidney anomalies. To provide an enhanced interpretation of those models' predictions, we proposed an adapted two-class representation and developed a multi-class model interpretation approach for problems with more than two labels and variable hierarchical grouping of labels. Additionally, we employed the explainable AI (XAI) visualization tools Grad-CAM and HiResCAM, to gain insights into model predictions and identify reasons for misclassifications. The study dataset consisted of 969 ultrasound images from unique patients; 646 control images and 323 cases of kidney anomalies, including 259 cases of unilateral urinary tract dilation and 64 cases of unilateral multicystic dysplastic kidney. The best performing model achieved a cross-validated area under the ROC curve of 91.28% ± 0.52%, with an overall accuracy of 84.03% ± 0.76%, sensitivity of 77.39% ± 1.99%, and specificity of 87.35% ± 1.28%. Our findings emphasize the potential of deep learning models in predicting kidney anomalies from limited prenatal ultrasound imagery. The proposed adaptations in model representation and interpretation represent a novel solution to multi-class prediction problems.
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Aprendizado Profundo , Nefropatias , Sistema Urinário , Gravidez , Feminino , Humanos , Ultrassonografia Pré-Natal/métodos , Diagnóstico Pré-Natal/métodos , Nefropatias/diagnóstico por imagem , Sistema Urinário/anormalidadesRESUMO
BACKGROUND: Low-dose aspirin is recommended for pregnant individuals at high-risk of developing preeclampsia, but less is known about those that develop preeclampsia even while using prophylactic aspirin for preeclampsia prevention as the best course of treatment. OBJECTIVES: The objective of this study is to investigate the risk factors with the highest risk of developing preeclampsia among pregnant individuals already using aspirin from high-risk obstetrical centers across five countries. DESIGN: This is a secondary analysis of pregnant individuals from the Folic Acid Clinical Trial (FACT) who were using prophylactic aspirin before 16 weeks gestation. The FACT randomized control trial took place in 70 high risk obstetrical centers in Canada, United Kingdom, Australia, Jamaica, and Argentina between 2011-2015. Participants were included if they had any of the risk factors for preeclampsia: diabetes, chronic hypertension, twin pregnancy, history of preeclampsia, and/or obesity (Body Mass Index ≥35). The outcomes of interest were preeclampsia and preterm preeclampsia (<37 weeks). Log binomial regressions assessed factors significantly associated with any preeclampsia or preterm-preeclampsia (<37 weeks) using adjusted risk ratios (ARR) and 95% confidence intervals (CI). RESULTS: There were 2296 pregnant individuals with complete information on aspirin included in this study. At baseline, all patients were at high risk of preeclampsia and were eligible for aspirin prophylaxis, however, only 660 (28.7%) were taking aspirin. Among the 660 pregnant individuals taking aspirin, 132 (20%) developed preeclampsia and 60 (9.09%) preterm preeclampsia. Among pregnant individuals using aspirin, the risks of preeclampsia were highest for twins (ARR:2.62, 95% CI: 1.68-4.11), history of preeclampsia (ARR: 2.42, 95% CI: 1.74-3.38), and hypertension (ARR:1.92, 95% CI: 1.37-2.69). Similar trends were found for preterm-preeclampsia for twins (ARR:4.10, 95% CI:2.15-7.82), history of preeclampsia (ARR:2.75, 95% CI:1.62-4.67), and hypertension (ARR:2.18, 95% CI:1.28-3.72). No significant differences were found for obesity or diabetes. CONCLUSION: These findings suggest that individuals with twin pregnancies, a history of preeclampsia, or hypertension may not benefit from aspirin to the same extent as those with other complications such as obesity or diabetes. Careful clinical monitoring for these risks factors is recommended and future research into the effectiveness in these populations would increase our understanding of the current best practice of prophylactic aspirin use to prevent preeclampsia. TRIAL REGISTRATION: Current Controlled Trials ISRCTN23781770 and ClinicalTrials.gov NCT01355159.
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Hipertensão , Pré-Eclâmpsia , Feminino , Humanos , Recém-Nascido , Gravidez , Aspirina/uso terapêutico , Ácido Fólico , Hipertensão/complicações , Obesidade/complicações , Pré-Eclâmpsia/epidemiologia , Pré-Eclâmpsia/prevenção & controle , Pré-Eclâmpsia/tratamento farmacológico , Gravidez de Alto Risco , Estudos Retrospectivos , Fatores de RiscoRESUMO
INTRODUCTION: Cannabis use in pregnancy and post partum is increasing. Accessibility to cannabis has expanded due to the legalisation of cannabis in Canada. Therefore, there is a critical need to monitor the impact of cannabis on pregnancy outcomes and infant neurodevelopment. This pilot study will assess the feasibility of modern recruitment and data collection strategies adapted to the current cannabis environment and inform the design of a multicentre prospective birth cohort. METHODS AND ANALYSIS: We will establish a pregnancy and birth cohort of 50 cannabis users and 50 non-users recruited before delivery. We will follow the participants at regular visits from recruitment to 12 weeks post partum. Participants will provide demographic and socioeconomic data, report their cannabis use patterns, and provide biological samples. Biological samples include maternal and infant urine and blood, breastmilk/chestmilk, cord blood, cord tissue, placenta and meconium. All samples will be processed and stored at -80°C until analysis by immunoassay or liquid chromatography-tandem mass spectrometry to determine the presence of cannabis metabolites. In addition, partners will be invited to provide additional socioeconomic and substance use data. ETHICS AND DISSEMINATION: Ethics was obtained from Ottawa Health Science Network Research Ethics Board through Clinical Trials Ontario (3791). Our findings will be published in peer-reviewed journals, presented at scientific conferences and shared broadly with patients, healthcare decision-makers, and project partners online and through social media. TRIAL REGISTRATION NUMBER: NCT05309226.Cite Now.
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Cannabis , Gravidez , Lactente , Feminino , Humanos , Projetos Piloto , Estudos Prospectivos , Coorte de Nascimento , Saúde do Lactente , Projetos de Pesquisa , OntárioRESUMO
Women who develop preeclampsia (PE) are at high risk for cardiovascular disease (CVD). Early identification of women with PE who may benefit the most from early cardiovascular risk screening and interventions remains challenging. Our objective was to assess whether cytokine and immune cell profiles after PE are helpful in distinguishing women at low and high CVD risk at 6-months postpartum. Individuals who developed PE were followed for immune cell phenotyping and plasma cytokine quantification at delivery, at 3-months, and at 6-months postpartum. Lifetime CVD risk was assessed at 6-months postpartum, and the immune cell and cytokine profiles were compared between risk groups at each time point. Among 31 participants, 18 (58.1%) exhibited high CVD-risk profiles at 6-months postpartum. The proportion of circulating NK-cells was significantly lower in high-risk participants at delivery (p = 0.04). At 3-months postpartum, high-risk participants exhibited a lower proportion of FoxP3+ regulatory T-cells (p = 0.01), a greater proportion of CD8+ T cells (p = 0.02) and a lower CD4+:CD8+ ratio (p = 0.02). There were no differences in immune cell populations at 6-months postpartum. There were no differences in plasma cytokines levels between risk groups at any time point. Subtle differences in immune cell profiles may help distinguish individuals at low and high CVD risk in the early postpartum period and warrants further investigation.
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Obesity is a well-recognized risk factor for pregnancy complications. Most studies to date are in large cohorts, with results presented in a way that assumes all women living with obesity are at equal risk. This study investigates which women living with obesity are at higher risk of specific pregnancy complications. A systematic search of MEDLINE and Embase identified 7894 prospective or retrospective cohort studies exploring predictors of adverse outcomes among pregnant women living with obesity. Following screening, 61 studies were deemed eligible. Studies were selected if the effects of exposure to any predictor amongst pregnant women living with obesity could be collected. Maternal characteristics assessed for association with adverse outcomes included maternal age, race/ethnicity, maternal height, mode of conception, complement activation factors, and history of various comorbidities/procedures. Gestational diabetes mellitus was the most studied outcome (n = 32), followed by preterm birth (n = 29), preeclampsia (n = 27), low birthweight infants (n = 20), small for gestational age newborns (n = 12), and stillbirth (n = 7). This review identified important characteristics that should be considered during the screening and follow-up sessions of pregnant women living with obesity, including pre-existing type 1 diabetes, maternal age < 20 years or ≥35 years, non-White ethnicity, abdominal adiposity obesity, and history of bariatric surgery.
Assuntos
Complicações na Gravidez , Nascimento Prematuro , Adulto , Feminino , Humanos , Lactente , Recém-Nascido , Obesidade/epidemiologia , Gravidez , Complicações na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Gestantes , Estudos Prospectivos , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: There is limited information on the prevalence of SARS-CoV-2 infection in obstetric settings in Canada, beyond the first wave of the COVID-19 pandemic (February to June 2020). We sought to describe the prevalence of SARS-CoV-2 infection in pregnant people admitted to triage units at a tertiary care hospital in Ottawa, Canada. METHODS: We conducted a descriptive study of pregnant people admitted to obstetric triage assessment units at The Ottawa Hospital between Oct. 19 and Nov. 27, 2020 (second local wave of the COVID-19 pandemic). Participants underwent SARS-CoV-2 polymerase chain reaction (PCR) (via naso- or oropharyngeal swabs) and serology testing upon admission. We excluded individuals younger than 18 years, those who did not speak English or French, those who enrolled in conflicting studies, those admitted for pregnancy termination and those triaged between 11:31 pm and 7:29 am. Swab and serology samples were analyzed using digital droplet PCR and enzyme-linked immunosorbent assays, respectively. We defined SARS-CoV-2 seropositivity as a positive result for immunoglobulin (Ig) G, either alone or in combination with IgM or IgA. RESULTS: Of the 632 eligible patients, 363 (57.4%) consented to participation and 362 collectively provided 284 swab and 352 blood samples eligible for analysis. Common reasons for declining participation included feeling overwhelmed or anxious, being worried about repercussions of testing, pain or discomfort with testing or disinterest in research. Participants were mostly multiparous (53.9%) and in their third trimester upon admission (88.4%). In all, 18 (4.9%) participants had evidence of SARS-CoV-2 exposure; 2 (0.7%) of 284 were positive for SARS-CoV-2 by PCR and 16 (4.5%) of 352 were positive for IgG antibodies to SARS-CoV-2. INTERPRETATION: During the second local wave of the COVID-19 pandemic, the prevalence of active SARS-CoV-2 infection among obstetric patients in Ottawa was 0.7% and seroprevalence was 4.5%. Our low participation rate highlights the need for improvements in patient education and public health messaging on the benefits of SARS-CoV-2 testing programs.
Assuntos
COVID-19 , Anticorpos Antivirais , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste para COVID-19 , Canadá/epidemiologia , Humanos , Imunoglobulina G , Pandemias , Prevalência , SARS-CoV-2/genética , Estudos SoroepidemiológicosRESUMO
OBJECTIVE: To develop and internally validate a deep-learning algorithm from fetal ultrasound images for the diagnosis of cystic hygromas in the first trimester. METHODS: All first trimester ultrasound scans with a diagnosis of a cystic hygroma between 11 and 14 weeks gestation at our tertiary care centre in Ontario, Canada were studied. Ultrasound scans with normal nuchal translucency were used as controls. The dataset was partitioned with 75% of images used for model training and 25% used for model validation. Images were analyzed using a DenseNet model and the accuracy of the trained model to correctly identify cases of cystic hygroma was assessed by calculating sensitivity, specificity, and the area under the receiver-operating characteristic (ROC) curve. Gradient class activation heat maps (Grad-CAM) were generated to assess model interpretability. RESULTS: The dataset included 289 sagittal fetal ultrasound images;129 cystic hygroma cases and 160 normal NT controls. Overall model accuracy was 93% (95% CI: 88-98%), sensitivity 92% (95% CI: 79-100%), specificity 94% (95% CI: 91-96%), and the area under the ROC curve 0.94 (95% CI: 0.89-1.0). Grad-CAM heat maps demonstrated that the model predictions were driven primarily by the fetal posterior cervical area. CONCLUSIONS: Our findings demonstrate that deep-learning algorithms can achieve high accuracy in diagnostic interpretation of cystic hygroma in the first trimester, validated against expert clinical assessment.