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We used a prospective cohort of pregnant women at 12 to 20 weeks gestation between 2002 and 2008 in Ottawa and Kingston to evaluate the impact of early pregnancy folic acid supplementation on the risk of gestational diabetes mellitus. Among 7552 eligible women, 84 (1.11%) were diagnosed of gestational diabetes mellitus. Non-significant associations were observed between gestational diabetes mellitus and folate supplementation, homocysteine levels, and methylenetetrahydrofolate reductase 677 TT genotype. Although we found no significant associations between folic acid supplementation and the risk of gestational diabetes mellitus, genetic associations were not confounded by lifestyle or socioeconomic factors, which may have biased previous studies.

Background Studies suggest maternal weight and weight gain during pregnancy may influence foetal immunological development. However, their role in the aetiology of allergic disease is unclear. Objectives We sought to examine the impact of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on the incidence of four common paediatric allergic diseases. Methods We conducted a retrospective, population-based cohort study of all singleton live births in Ontario, Canada between 2012 and 2014, using maternal-newborn records from the provincial birth registry linked with health administrative databases. Neonates were followed up to 7 years for anaphylaxis, asthma, dermatitis and rhinitis, identified through validated algorithms based on healthcare encounters. We multiply imputed missing data and employed Cox proportional-hazards models to calculate adjusted hazard ratios (aHR) with 95% confidence intervals (CI). To test the robustness of our findings, we also conducted several sensitivity analyses, including probabilistic bias analyses for exposure and outcome misclassification. All methods were prespecified in a published protocol. Results Of the 248,017 infants followed, 52% were born to mothers with a pre-pregnancy BMI in the normal range and only 19% were born to mothers with adequate weight gain during pregnancy. Incidence rates (per 100,000 person-days) for anaphylaxis, asthma, dermatitis and rhinitis were 0.22, 6.80, 12.41 and 1.54, respectively. Compared with normal BMI, maternal obesity was associated with increased hazards of asthma in offspring (aHR 1.08, 95% CI 1.05, 1.11), but decreased hazards of anaphylaxis (aHR 0.83, 95% CI 0.69, 0.99) and dermatitis (aHR 0.97, 95% CI 0.94, 0.99). In contrast, maternal underweight was associated with increased hazards of dermatitis (aHR 1.06, 95% CI 1.02, 1.10). We found no associations between pre-pregnancy BMI and rhinitis or GWG and any allergic outcome, and no evidence of effect measures modification by infant sex. Conclusions These findings provide support for the involvement of maternal pre-pregnancy BMI in paediatric allergic disease development.

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.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.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.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: 30–36). 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.

IntroductionHyperglycaemia during pregnancy has been considered as one of the risk factors for cardiovascular diseases (CVDs) among women. Although the evidence regarding the association between gestational diabetes mellitus (GDM) and subsequent CVD has been synthesised, there are no systematic reviews covering the evidence of the association among the non-GDM population. This systematic review and meta-analysis, therefore, aim to fill the gap by summarising existing evidence on the association between maternal glucose levels and the risk of future CVD in pregnant women with or without a diagnosis of GDM.Methods and analysisThis systematic review protocol was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guidelines. Comprehensive literature searches were performed in the following electronic databases: MEDLINE, EMBASE and CINAHL to identify relevant papers from inception to 31 December 2022. All observational studies (case–control studies, cohort studies and cross-sectional studies) will be included. Two reviewers will perform the abstract and full-text screening based on the eligibility criteria through Covidence. The Newcastle-Ottawa Scale will be used to assess the methodological quality of included studies. Statistical heterogeneity will be assessed by using the I2test and Cochrane’s Q test. If the included studies are found to be homogeneous, pooled estimates will be calculated and meta-analysis will be performed using Review Manager 5 (RevMan) software. Random effects will be used to determine weights for meta-analysis, if needed. Pre-specified subgroup analysis and sensitivity analysis will be performed, if needed. The study results will be presented in the sequence of main outcomes, secondary outcomes and important subgroup analysis for each type of glucose level separately.Ethics and disseminationGiven no original data will be collected, ethics approval is not applicable for this review. The results of this review will be disseminated by publication and conference presentation.PROSPERO registration numberCRD42022363037.

BACKGROUND: It is unclear whether the clinical burden of postpartum mental illness has increased during the COVID-19 pandemic. We sought to compare physician visit rates for postpartum mental illness in Ontario, Canada, during the pandemic with rates expected based on prepandemic patterns. METHODS: In this population-based, repeated cross-sectional study using linked health administrative databases in Ontario, Canada, we used negative binomial regression to model expected visit rates per 1000 postpartum people for March–November 2020 based on prepandemic data (January 2016–February 2020). We compared observed visit rates to expected visit rates for each month of the pandemic period, generating absolute rate differences, incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). The primary outcome was a visit to a primary care physician or a psychiatrist for any mental disorder. We stratified analyses by maternal sociodemographic characteristics. RESULTS: In March 2020, the visit rate was 43.5/1000, with a rate difference of 3.11/1000 (95% CI 1.25–4.89) and an IRR of 1.08 (95% CI 1.03–1.13) compared with the expected rate. In April, the rate difference (10.9/1000, 95% CI 9.14–12.6) and IRR (1.30, 95% CI 1.24–1.36) were higher; this level was generally sustained through November 2020. From April–November, we observed elevated visit rates across provider types and for diagnoses of anxiety, depressive and alcohol or substance use disorders. Observed increases from expected visit rates were greater for people 0–90 days postpartum compared with 91–365 days postpartum; increases were small among people living in low-income neighbourhoods. Public health units in the northern areas of the province did not see sustained elevations in visit rates after July; southern health units had elevated rates through to November. INTERPRETATION: Increased visits for mental health conditions among postpartum people during the first 9 months of the COVID-19 pandemic suggest an increased need for effective and accessible mental health care for this population as the pandemic progresses.

The importance of data quality to correctly determine prevalence estimates of child anthropometric failures has been a contentious issue among policymakers and researchers. Our research objective was to ascertain the impact of improved DHS data quality on the prevalence estimates of stunting, wasting, and underweight. The study also looks for the drivers of data quality. Using five data quality indicators based on age, sex, anthropometric measurements, and normality distribution, we arrive at two datasets of differential data quality and their estimates of anthropometric failures. For this purpose, we use the 2005–2006 and 2015–2016 NFHS data covering 311,182 observations from India. The prevalence estimates of stunting and underweight were virtually unchanged after the application of quality checks. The estimate of wasting had fallen 2 percentage points, indicating an overestimation of the true prevalence. However, this differential impact on the estimate of wasting was driven by the flagging procedure’s sensitivity and was in accordance with empirical evidence from existing literature. We found DHS data quality to be of sufficiently high quality for the prevalence estimates of stunting and underweight, to not change significantly after further improving the data quality. The differential estimate of wasting is attributable to the sensitivity of the flagging procedure.

Opioids cover a broad class of natural, synthetic and semi-synthetic drugs that act on opioid receptors to produce powerful analgesic effects. Rates of opioid use and opioid agonist maintenance treatment have increased substantially in recent years, particularly among women. Trends and outcomes of opioids use on fertility, pregnancy and breastfeeding, and longer-term child developmental outcomes have not been well-described. Here, we review the existing literature on the health effects of opioid use on female fertility, pregnancy, breastmilk and the exposed infant. We find that the current literature is primarily concentrated on the impact of opioid use in pregnancy and neonatal outcomes, with little exploration of effects on fertility. Studies are limited in number, some with small sample sizes, and many are hampered by methodological challenges related to confounding and other potential biases. Opioid use is becoming more prevalent due to environmental pressures such as COVID-19. More research is needed to better elucidate its effects on reproductive health among younger women and support the development of evidence-based recommendations for safe prescription practices and public health messaging.

Background Approximately one in five pregnant women have obesity. Obesity is associated with an increased risk of antenatal, intrapartum, and perinatal complications, but many women with obesity have uncomplicated pregnancies. At a time where maternity services are advocating for women to make informed choices, knowledge of the chance of having an uncomplicated (healthy) pregnancy is essential. The objective of this study was to calculate the rate of uncomplicated pregnancy in women with obesity and evaluate factors associated with this outcome. Methods This prospective cohort study was conducted using the Ontario birth registry dataset in Canada (703,115 women, April 2012–March 2017). The rate of uncomplicated or complicated composite pregnancy outcomes (hypertensive disorders of pregnancy, gestational diabetes, preterm birth, neonate small- or large- for gestational age at birth, congenital anomaly, fetal death, antepartum bleeding or preterm prelabour membrane rupture) were calculated for women with and without obesity. Associations between uncomplicated pregnancy and maternal characteristics were explored in a population of women with obesity but without other pre-existing co-morbidities (e.g., essential hypertension) or obstetric risks identified in the first trimester (e.g., multiple pregnancy), using log binomial regression analysis. Results Of the studied Ontario maternity population (body mass index not missing) 17·7% (n = 117,236) were obese. Of these 20·6% had pre-existing co-morbidities or early obstetric complicating factors. Amongst women with obesity but without early complicating factors, 58·2% (n = 54,191) experienced pregnancy without complication; this is in comparison to 72·7% of women of healthy weight and no early complicating factors. Women with obesity and no early pregnancy complicating factors are more likely to have an uncomplicated pregnancy if they are multiparous, younger, more affluent, of White or Black ethnicity, of lower weight, with normal placental-associated plasma protein-A and/or spontaneously conceived pregnancies. Conclusions The study demonstrates that over half of women with obesity but no other pre-existing medical or early obstetric complicating factors, proceed through pregnancy without adverse obstetric complication. Care in lower-risk settings can be considered as their outcomes appear similar to those reported for low-risk nulliparous women. Further research and predictive tools are needed to inform stratification of women with obesity.

Education is considered one of the most robust determinants of health. However, it is unclear whether maternal education and paternal education have differential impacts on perinatal health outcomes. We assess maternal and paternal education differences and their association with adverse birth outcomes in a large birth cohort from Ontario, Canada. The OaK Birth Cohort recruited patients from Ontario, Canada, between October 2002 and April 2009. We recruited mothers were recruited between 12 and 20 weeks’ gestation and collected both mother and infant data. The final sample size of the cohort was 8,085 participants. We use logistic regression to model the probability of preterm birth (less than 34 and 37 weeks’ gestation), small-for-gestational-age (SGA), or stillbirth as a function of maternal and paternal educational attainment. We adjust for household-level income, maternal and paternal race and ethnicity, and compare the strength of the association between maternal and paternal education on outcomes using Wald tests. 7,928 mother-father-offspring triads were available for the current analysis. 75% of mothers and fathers had college or university level education, and 8.7% of mothers experienced preterm delivery. Compared to mothers with college or university education, mothers with a high school education had an odds ratio of 1.37 (95% CI: 1.01–1.87) for SGA. Paternal education was not associated with infant outcomes. Comparing the odds ratios for maternal education and paternal education showed a stronger association than paternal education at the high school level for SGA birth (difference in odds ratio: 1.95, 95% CI: 1.13–3.36, p = .016) among women at least 25 years old. Maternal education was associated with SGA, and this effect was more robust than paternal education, but both associations were weaker than previously reported.

Cannabis use in pregnancy has increased1,2, and many women continue to use it throughout pregnancy3. With the legalization of recreational cannabis in many jurisdictions, there is concern about potentially adverse childhood outcomes related to prenatal exposure4. Using the provincial birth registry containing information on cannabis use during pregnancy, we perform a retrospective analysis of all live births in Ontario, Canada, between 1 April 2007 and 31 March 2012. We link pregnancy and birth data to provincial health administrative databases to ascertain child neurodevelopmental outcomes. We use matching techniques to control for confounding and Cox proportional hazards regression models to examine associations between prenatal cannabis use and child neurodevelopment. We find an association between maternal cannabis use in pregnancy and the incidence of autism spectrum disorder in the offspring. The incidence of autism spectrum disorder diagnosis was 4.00 per 1,000 person-years among children with exposure compared to 2.42 among unexposed children, and the fully adjusted hazard ratio was 1.51 (95% confidence interval: 1.17–1.96) in the matched cohort. The incidence of intellectual disability and learning disorders was higher among offspring of mothers who use cannabis in pregnancy, although less statistically robust. We emphasize a cautious interpretation of these findings given the likelihood of residual confounding. In a cohort of nearly half a million births in Ontario, Canada, maternal cannabis use in pregnancy was associated with an increased incidence of autism spectrum disorder diagnosis in the offspring.

To determine the efficacy of high-dose folic acid for the prevention of preeclampsia in twin pregnancies.Secondary analysis of a randomized controlled trial in 70 obstetrical sites in Argentina, Australia, Canada, Jamaica, and the UK between 2011 and 2015. Eligible women pregnant with twins who were aged 18 y or older and between 8 and 16 completed weeks' gestation were randomized between to receive daily high-dose folic acid (4.0-5.1 mg) or placebo. The primary outcome was preeclampsia, presenting as hypertension after 20 weeks' gestation with significant proteinuria. Secondary outcomes included severe preeclampsia, preterm birth, and adverse fetal and neonatal outcomes.Of 2464 participants randomized between 18 April 2011 and 14 December 2015, 462 (18.8%) had a confirmed twin pregnancy. Thirty-four of these participants withdrew consent or did not have primary outcome data available, and 428 women were analyzed. The rate of preeclampsia was significantly higher in the folic acid group compared to the placebo group in crude analyses (17.2 versus 9.9%; relative risk 1.75 [95% CI 1.06-2.88],High-dose folic acid supplementation was not significantly associated with preeclampsia in a subgroup of twin pregnancies. Although a suggested elevated risk cannot be confirmed, these results may help to gain novel insights in the etiology of preeclampsia, which continues to be poorly understood.ClinicalTrials.gov NCT01355159.

Maternal recall of birthweight is a convenient and cost-effective way to obtain birthweight measurements when official records are unavailable. It is important to assess the validity of maternal recall of birthweight before using these measurements to draw conclusions about a population. This is secondary analysis of data from a previous cohort study. We analyzed actual and reported birthweights of 200 mother-and-child pairs from Southern India. We validated maternal report of birthweight by generating correlation coefficients, summary statistics, and Bland-Altman plots. We ran simulations to evaluate how misclassification as low or normal birthweight changed with the mean birthweight of the cohort. Reported birthweight was strongly correlated with actual birthweight (r=0.80, P

Background: Cannabis use has increased in Canada since its legalization in 2018, includingamong pregnant women who may be motivated to use cannabis to reduce symptoms ofnausea and vomiting. However, a growing body of research suggests that cannabis useduring pregnancy may harm the developing fetus. As a result, patients increasingly seekmedical advice from online sources, but these platforms may also spread anecdotaldescriptions or misinformation. Given the possible disconnect between online messaging andevidence-based research about the effects of cannabis use during pregnancy, there is apotential for advice taken from social media to cause harm.Objectives: To quantify the volume and tone of English-language posts related to cannabisuse in pregnancy from January 2012 to July 2021.Methods: Modelling published frameworks for scoping reviews, we will collect publiclyavailable posts from Twitter that mention cannabis use during pregnancy and employ theTwitter Application Programming Interface (API) for Academic Research to extract data fromtweets, including public metrics such as the number of likes, retweets and quotes, as well ashealth effect mentions, sentiment, location and users interests. These data will be used toquantify how cannabis use during pregnancy is discussed on Twitter and to build a qualitativeprofile of supportive and opposing posters.Results: The CHEO Research Ethics Board reviewed our project and granted an exemptionin May 2021. As of September 2021, we have gained approval to use the Twitter API forAcademic Research and have developed a preliminary search strategy that returns over 2million unique tweets posted between 2012 and 2020.Conclusions: Understanding how Twitter is being used to discuss cannabis use duringpregnancy will help public health agencies and healthcare providers assess the messagingpatients may be receiving and develop communication strategies to counter misinformation,especially in geographical regions where legalization is recent or imminent. Most importantly,we foresee that our findings will assist expecting families in making informed choices aboutwhere they choose to access advice about using cannabis during pregnancy.

Background Cannabis use has increased in Canada since its legalization in 2018, including among pregnant women who may be motivated to use cannabis to reduce symptoms of nausea and vomiting. However, a growing body of research suggests that cannabis use during pregnancy may harm the developing fetus. As a result, patients increasingly seek medical advice from online sources, but these platforms may also spread anecdotal descriptions or misinformation. Given the possible disconnect between online messaging and evidence-based research about the effects of cannabis use during pregnancy, there is a potential for advice taken from social media to affect the health of mothers and their babies. Objective This study aims to quantify the volume and tone of English language posts related to cannabis use in pregnancy from January 2012 to December 2021. Methods Modeling published frameworks for scoping reviews, we will collect publicly available posts from Twitter that mention cannabis use during pregnancy and use the Twitter Application Programming Interface for Academic Research to extract data from tweets, including public metrics such as the number of likes, retweets, and quotes, as well as health effect mentions, sentiment, location, and users’ interests. These data will be used to quantify how cannabis use during pregnancy is discussed on Twitter and to build a qualitative profile of supportive and opposing posters. Results The CHEO Research Ethics Board reviewed our project and granted an exemption in May 2021. As of December 2021, we have gained approval to use the Twitter Application Programming Interface for Academic Research and have developed a preliminary search strategy that returns over 3 million unique tweets posted between 2012 and 2021. Conclusions Understanding how Twitter is being used to discuss cannabis use during pregnancy will help public health agencies and health care providers assess the messaging patients may be receiving and develop communication strategies to counter misinformation, especially in geographical regions where legalization is recent or imminent. Most importantly, we foresee that our findings will assist expecting families in making informed choices about where they choose to access advice about using cannabis during pregnancy. Trial Registration Open Science Framework 10.17605/OSF.IO/BW8DA; www.osf.io/6fb2e International Registered Report Identifier (IRRID) PRR1-10.2196/34421

BACKGROUND Cannabis use has increased in Canada since its legalization in 2018, including among pregnant women who may be motivated to use cannabis to reduce symptoms of nausea and vomiting. However, a growing body of research suggests that cannabis use during pregnancy may harm the developing fetus. As a result, patients increasingly seek medical advice from online sources, but these platforms may also spread anecdotal descriptions or misinformation. Given the possible disconnect between online messaging and evidence-based research about the effects of cannabis use during pregnancy, there is a potential for advice taken from social media to affect the health of mothers and their babies. OBJECTIVE This study aims to quantify the volume and tone of English language posts related to cannabis use in pregnancy from January 2012 to December 2021. METHODS Modeling published frameworks for scoping reviews, we will collect publicly available posts from Twitter that mention cannabis use during pregnancy and use the Twitter Application Programming Interface for Academic Research to extract data from tweets, including public metrics such as the number of likes, retweets, and quotes, as well as health effect mentions, sentiment, location, and users’ interests. These data will be used to quantify how cannabis use during pregnancy is discussed on Twitter and to build a qualitative profile of supportive and opposing posters. RESULTS The CHEO Research Ethics Board reviewed our project and granted an exemption in May 2021. As of December 2021, we have gained approval to use the Twitter Application Programming Interface for Academic Research and have developed a preliminary search strategy that returns over 3 million unique tweets posted between 2012 and 2021. CONCLUSIONS Understanding how Twitter is being used to discuss cannabis use during pregnancy will help public health agencies and health care providers assess the messaging patients may be receiving and develop communication strategies to counter misinformation, especially in geographical regions where legalization is recent or imminent. Most importantly, we foresee that our findings will assist expecting families in making informed choices about where they choose to access advice about using cannabis during pregnancy. CLINICALTRIAL Open Science Framework 10.17605/OSF.IO/BW8DA; www.osf.io/6fb2e INTERNATIONAL REGISTERED REPORT PRR1-10.2196/34421

IntroductionCannabis 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 analysisWe 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 disseminationEthics 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 numberNCT05309226.Cite Now

Schools are important contexts for adolescent health and health-risk behaviors, but how stable is this relationship? We develop a conceptual model based on Ecological Systems Theory describing the changing role of schools for adolescent health outcomes-in this case, teen e-cigarette use. To examine this change, we fit Bayesian multilevel regression models to two-year intervals of pooled cross-sectional data from the 2011-2017 U.S. National Youth Tobacco Survey, a school-based study of the nicotine use behaviors of roughly 65,000 middle and high school students (49.5% female; 41.1% nonwhite; x̄ age of 14.6 ranging from 9 to 18) from over 700 schools. We hypothesized that school-level associations with student e-cigarette use diminished over time as the broader popularity of e-cigarettes increased. Year-specific variance partitioning coefficients (VPC) derived from the multilevel models indicated a general decrease in the extent to which e-cigarette use clusters within specific schools, suggesting that students across schools became more uniform in their propensity to vape over the study period. This is above and beyond adjustments for personal characteristics and vicarious exposure to smoking via friends and family. Across all years, model coefficients indicate a positive association between attending schools where vaping is more versus less common and student-level odds of using e-cigarettes, suggesting that school contexts are still consequential to student vaping, but less so than when e-cigarettes were first introduced to the US market. These findings highlight how the health implications of multiply-embedded ecological systems like schools shift over time with concomitant changes in other ecological features including those related to policy, culture, and broader health practices within society. Though not uniformly reported in multilevel studies, variance partitioning coefficients could be used more thoughtfully to empirically illustrate how the influence of multiple developmentally-relevant contexts shift in their influence on teen health over time.

Essentials Low-molecular-weight heparin (LMWH) is used to prevent venous thromboembolism (VTE) in pregnancy. We evaluated the association between LMWH and large for gestational age (LGA) infants. We found no significant associations between LMWH use and LGA. LMWH does not appear to increase the risk for the delivery of an LGA infant. SUMMARY: Background Low-molecular-weight heparin (LMWH), an anticoagulant, is the recommended drug for thromboprophylaxis and treatment of venous thromboembolism (VTE) in pregnancy. During pregnancy, LMWH is routinely prescribed to mothers with an increased risk of VTE or with a history of thrombosis. Although clinical reports of larger offspring born to women administered LMWH have been noted, no studies to date have evaluated or associated the use of LMWH and large for gestational age (LGA) infants. Objectives To determine whether there is an association between LMWH usage in mothers and the prevalence of LGA. Patients/Methods We performed an analysis of the Ottawa and Kingston (OaK) Birth Cohort and report characteristics of LMWH and association LGA (> 10%ile). We used coarsened exact matching (CEM) methods to account for bias and confounding. Results A total of 7519 women from the OaK Birth Cohort were included; 59 were administered LMWH during pregnancy (0.78%). Mothers prescribed LMWH had significantly greater BMI (P = 0.0001), age (P = 0.0001) and parity (P = 0.02). Gestational length was shorter among women administered LMWH compared to those without treatment (37.7 ± 2.0 vs. 39.2 ± 2.0, P

There is conflicting evidence on the association between intrapartum epidural analgesia and risk of autism spectrum disorder (ASD) in offspring.To evaluate the association between intrapartum epidural analgesia and the risk of ASD in offspring.This population-based cohort study was conducted in Ontario, Canada, using the health and administrative records of singleton live births by vaginal delivery between April 1, 2006, and March 31, 2014. Neonates with less than 24 weeks' gestation or weighing less than 500 g were excluded. Offspring were followed up from 18 months of age until ASD diagnosis, loss to follow-up, or the end of the study (December 31, 2020), whichever occurred first. Exposure, covariate, and outcome data were obtained using provincial health administrative databases.Any intrapartum exposure to epidural or combined spinal-epidural analgesia.The primary outcome was ASD diagnosis after 18 months of age. Inverse probability of treatment weighting (IPTW) of Cox proportional hazards regression models was used to estimate the hazard ratio (HR) of intrapartum epidural analgesia and ASD in offspring. Offspring head injury was used as a control outcome. Models were adjusted for maternal sociodemographic factors, health behaviors, and medical and obstetrical history as well as labor, delivery, and offspring characteristics. Post hoc analyses included restriction to term neonates, a conditional within-mother analysis, exclusion of records with concomitant intrapartum pain management exposures, a complete case analysis, use of an alternative ASD definition, and estimation of the average treatment effect in the treated group.Among the 650 373 mother-offspring pairs included in the study, 418 761 (64.4%) were exposed to intrapartum epidural analgesia. The mean (SD) maternal age at delivery was 29.7 (5.5) years; the offspring had a mean (SD) gestational age at delivery of 39.1 (1.6) weeks and included 329 808 male newborns (50.7%). The exposed and unexposed groups were similar in all maternal and newborn characteristics after IPTW (standardized difference0.10). Autism spectrum disorder was diagnosed in 7546 offspring (1.8%) of mothers who received intrapartum epidural analgesia (incidence rate, 18.8 [95% CI, 18.4-19.3] per 10 000 person-years) compared with 3234 offspring (1.4%) who were unexposed (incidence rate, 14.4 [95% CI, 13.9-14.9] per 10 000 person-years). The crude HR for ASD associated with intrapartum epidural analgesia was 1.30 (95% CI, 1.25-1.36), and the IPTW-adjusted HR was 1.14 (95% CI, 1.08-1.21). Results did not qualitatively differ in post hoc analyses.Results of this study showed that intrapartum epidural analgesia was associated with a small increase in risk for ASD in offspring. The biological plausibility of this association, however, remains unclear, and the finding must be interpreted with caution.

Rationale: Cardiovascular risk varies across communities in Canada. Community-level differences in contextual factors may influence risk factor development.Methods: We audited urban and rural Canad...

Contextual determinants of health in Canada include community demographics, tobacco, food, and alcohol. We developed an on-line and highly accessible interactive map containing information ...

Objective Forthcoming legislative changes will legalize and make cannabis widely available in Canada. We conducted an analysis of Ontario’s birth registry to determine recent trends and correlates of cannabis use in pregnancy. Methods We conducted a population-based retrospective cohort study assembled from the Better Outcomes Registry & Network (BORN) Ontario database, covering live births and stillbirths in Ontario between April 2012 and December 2017. Trends in self-reported cannabis use in pregnancy were analyzed according to maternal age and area-level socio-economic status (SES) using log binomial regression analysis. Results A total of 10,731 women reported cannabis use in pregnancy. Prevalence increased from 1.2% in 2012 to 1.8% in 2017 (p-trend

Summary Background Data are scarce on the availability and affordability of essential medicines for diabetes. Our aim was to examine the availability and affordability of metformin, sulfonylureas, and insulin across multiple regions of the world and explore the effect of these on medicine use. Methods In the Prospective Urban Rural Epidemiology (PURE) study, participants aged 35–70 years (n=156 625) were recruited from 110 803 households, in 604 communities and 22 countries; availability (presence of any dose of medication in the pharmacy on the day of audit) and medicine cost data were collected from pharmacies with the Environmental Profile of a Community's Health audit tool. Our primary analysis was to describe the availability and affordability of metformin and insulin and also commonly used and prescribed combinations of two medicines for diabetes management (two oral drugs, metformin plus a sulphonylurea [either glibenclamide (also known as glyburide) or gliclazide] and one oral drug plus insulin [metformin plus insulin]). Medicines were defined as affordable if the cost of medicines was less than 20% of capacity-to-pay (the household income minus food expenditure). Our analyses included data collected in pharmacies and data from representative samples of households. Data on availability were ascertained during the pharmacy audit, as were data on cost of medications. These cost data were used to estimate the cost of a month's supply of essential medicines for diabetes. We estimated affordability of medicines using income data from household surveys. Findings Metformin was available in 113 (100%) of 113 pharmacies from high-income countries, 112 (88·2%) of 127 pharmacies in upper-middle-income countries, 179 (86·1%) of 208 pharmacies in lower-middle-income countries, 44 (64·7%) of 68 pharmacies in low-income countries (excluding India), and 88 (100%) of 88 pharmacies in India. Insulin was available in 106 (93·8%) pharmacies in high-income countries, 51 (40·2%) pharmacies in upper-middle-income countries, 61 (29·3%) pharmacies in lower-middle-income countries, seven (10·3%) pharmacies in lower-income countries, and 67 (76·1%) of 88 pharmacies in India. We estimated 0·7% of households in high-income countries and 26·9% of households in low-income countries could not afford metformin and 2·8% of households in high-income countries and 63·0% of households in low-income countries could not afford insulin. Among the 13 569 (8·6% of PURE participants) that reported a diagnosis of diabetes, 1222 (74·0%) participants reported diabetes medicine use in high-income countries compared with 143 (29·6%) participants in low-income countries. In multilevel models, availability and affordability were significantly associated with use of diabetes medicines. Interpretation Availability and affordability of essential diabetes medicines are poor in low-income and middle-income countries. Awareness of these global differences might importantly drive change in access for patients with diabetes. Funding Full funding sources listed at the end of the paper (see Acknowledgments).

BACKGROUND: Data on the effect of cesarean delivery on maternal request (CDMR) on maternal and neonatal outcomes are inconsistent and often limited by inadequate case definitions and other methodological issues. Our objective was to evaluate the trends, determinants and outcomes of CDMR using an intent-to-treat approach. METHODS: We designed a population-based retrospective cohort study using data on low-risk pregnancies in Ontario, Canada (April 2012–March 2018). We assessed temporal trends and determinants of CDMR. We estimated the relative risks for component and composite outcomes used in the Adverse Outcome Index (AOI) related to planned CDMR compared with planned vaginal delivery using generalized estimating equation models. We compared the Weighted Adverse Outcome Score (WAOS) and the Severity Index (SI) across planned modes of delivery using analysis of variance. RESULTS: Of 422 210 women, 0.4% (n = 1827) had a planned CDMR and 99.6% (n = 420 383) had a planned vaginal delivery. The prevalence of CDMR remained stable over time at 3.9% of all cesarean deliveries. Factors associated with CDMR included late maternal age, higher education, conception via in vitro fertilization, anxiety, nulliparity, being White, delivery at a hospital providing higher levels of maternal care and obstetrician-based antenatal care. Women who planned CDMR had a lower risk of adverse outcomes than women who planned vaginal delivery (adjusted relative risk 0.42, 95% confidence interval [CI] 0.33 to 0.53). The WAOS was lower for planned CDMR than planned vaginal delivery (mean difference −1.28, 95% CI −2.02 to −0.55). The SI was not statistically different between groups (mean difference 3.6, 95% CI −7.4 to 14.5). Interpretation: Rates of CDMR have not increased in Ontario. Planned CDMR is associated with a decreased risk of short-term adverse outcomes compared with planned vaginal delivery. Investigation into the long-term implications of CDMR is warranted.

Background Racial disparities in adverse perinatal outcomes have been studied in other countries, but little has been done for the Canadian population. In this study, we sought to examine the disparities in adverse perinatal outcomes between Asians and Caucasians in Ontario, Canada. Methods We conducted a population-based retrospective cohort study that included all Asian and Caucasian women who attended a prenatal screening and resulted in a singleton birth in an Ontario hospital (April 1st, 2015-March 31st, 2017). Generalized estimating equation models were used to estimate the independent adjusted relative risks and adjusted risk difference of adverse perinatal outcomes for Asians compared with Caucasians. Results Among 237,293 eligible women, 31% were Asian and 69% were Caucasian. Asians were at an increased risk of gestational diabetes mellitus, placental previa, early preterm birth (th percentile, rd percentile), neonatal intensive care unit admission, and hyperbilirubinemia requiring treatment, but had lower risks of preeclampsia, macrosomia (birth weight > 4000 g), large-for-gestational-age neonates, 5-min Apgar score Conclusion There are significant differences in several adverse perinatal outcomes between Asians and Caucasians. These differences should be taken into consideration for clinical practices due to the large Asian population in Canada.

Background Patients who present to emergency departments after intentional self-harm are at an increased risk of dying by suicide. This applies particularly to men, who represent nearly two-thirds of those who die by suicide in Ontario. One way of potentially addressing this gap is to offer a course of blended problem-solving therapy, comprised of a brief course of evidence-based psychotherapy for individuals at risk for suicide, facilitated by the use of a patient-facing smartphone application and a clinician-facing “dashboard.” This approach has the potential to combine the benefits of face-to-face therapy and technology to create a novel intervention. Methods This is a cohort study nested within a larger pragmatic multicentre pre- and post-design cluster randomised trial. Suicidal ideation assessed by the Beck Scale for Suicide Ideation is the primary outcome variable. Secondary outcome measures include depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder 7-item scale), post-traumatic stress disorder (Primary Care PTSD Screen), health-related quality of life (EuroQol 5-dimension 5-level questionnaire), meaning in life (Experienced Meaning in Life Scale), perceived social supports (Multidimensional Scale of Perceived Social Support), alcohol use (Alcohol Use Disorders Identification Test), drug use (Drug Abuse Screening Test Short Form 10), problem-solving skills (Social Problem-Solving Inventory–Revised Short Form), and self-reported healthcare costs, as well as health service use measured using Ontario administrative health data. A process evaluation will also be conducted following study completion. Discussion The cohort study will test whether better adherence to the intervention results in better outcomes. The value of the cohort study design is that we can examine in more detail certain subgroups or other variables that are not available in the larger cluster randomised trial. This trial will aim to improve standards by informing best practice in management of men who self-harm and present to hospitals in Ontario. Trial registration ClinicalTrials.gov, NCT03473535. Registered on March 22, 2018.

Background: Uterine clear cell carcinoma (UCCC) is a rare histological type of endometrial cancer with poor prognosis and high risk of tumor relapse. Although adjuvant chemotherapy (CT) and/or radiotherapy (RT) are often recommended for early stage UCCC patients, the effectiveness of these treatment strategies remains unclear. Methods: Systematic review and meta-analysis were applied to evaluate treatment-related outcomes of stage I-II UCCC patients. Search strategy was applied using electronic databases until June 1st, 2019. Inclusion criteria were retrospective, observational and prospective studies that reported outcome of UCCC patients receiving adjuvant therapy. Clinical endpoints like overall survival (OS) and progression-free survival (PFS) were evaluated. Data were extracted by two independent reviewers and a meta-analysis was performed. Results: 12 articles with a total of 3845 patients were analyzed. Overall, adjuvant CT after surgery could improve 5 year-OS significantly compared to patients without CT (odds ratio (OR): 0.75, 95% confidence interval (CI): 0.58-0.95; p=0.02). In comparison, RT could also improve OS in UCCC patients of early stage (OR: 0.61, 95% CI: 0.46-0.82; p=0.001) compared to the patients without RT, in US and Europe patients. Lastly, when comparing the patients undergoing both CT and RT with those receiving CT or RT alone, no further improvement in OS was observed (OR: 0.95, 95% CI: 0.53-1.72; P=0.88). Conclusions: Either CT or RT after surgery could improve the OS of early stage of UCCC patients. However, combinatorial CT and RT treatment did not improve the OS compared with CT or RT treatment alone.