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Importance: Gestational exposure to particulate matter (PM) air pollution may increase the risk of childhood obesity, but the impact of reducing air pollution during pregnancy on obesity-related outcomes in childhood has not been examined., Objective: To assess the impact of reducing gestational PM exposure on body mass index (BMI) at two years of age., Methods: In this single-blind, parallel group randomized controlled trial in Ulaanbaatar Mongolia, we randomly assigned 540 pregnant women to receive 1-2 portable high efficiency particulate air (HEPA) filter air cleaners or no air cleaners. We measured height and weight when children were a mean age of 23.8 months. Our primary outcome was age- and sex-specific BMI z-score based on the World Health Organization 2007 Growth Charts. Secondary outcomes included age- and sex-specific weight z score, overweight/obesity (defined as BMI z-score > 2.00), and catch-up growth (defined using various cut-offs to identify children with relatively low birth weight for sex and gestational age and relatively high age- and sex-specific weight in childhood). We imputed missing outcome data using multiple imputation with chained equations and our primary analysis was by intention to treat (ITT). We estimated intervention effects on continuous and binary outcomes using linear and logistic regression, respectively., Results: After excluding known miscarriages, still births, and neonatal deaths our analysis included 480 children (235 control and 245 intervention). The mean (SD) child BMI z score was 0.79 (1.0); 9.8% of children were overweight or obese. The mean BMI z score of children who were randomly assigned to the intervention group was 0.16-units lower (95% CI: -0.35, 0.04) than children in the control group. The intervention was also associated with reductions in overweight/obesity (odds ratio = 0.59; 95% CI: 0.31, 1.12). Catch-up growth occurred less frequently in the intervention group, but effect estimates varied depending on the specific definition of catch-up growth and confidence intervals consistently spanned no effect., Conclusions: We found that the use of portable air cleaners during pregnancy was associated with improvements in obesity-related outcomes, although some effect estimates lacked precision. Reducing PM exposure during pregnancy may lead to improvements in cardiometabolic health in childhood., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Rationale: Sleep duration is critical to growth, learning, and immune function development in infancy. Strategies to ensure that national recommendations for sleep duration in infants are met require knowledge of perinatal factors that affect infant sleep., Objectives: To investigate the mechanistic pathways linking maternal education and infant sleep., Methods: An observational study was conducted on 619 infants whose mothers were enrolled at the Edmonton site of the CHILD birth cohort. Infant sleep duration at three months was assessed using the Brief Infant Sleep Questionnaire. Maternal education was collected via maternal report. Prenatal and postnatal depression scores were obtained from the 20-item Center for Epidemiologic Studies Depression Scale (CES-D). Birth records and maternal report were the source of covariate measures. Mediation analysis (PROCESS v3.0) was used to examine the indirect effects of maternal education on infant sleep duration mediated through prenatal depression and birth mode., Measurements and Main Results: At three months of age, infants slept on average 14.1 h. Lower maternal education and prenatal depression were associated with significantly shorter infant sleep duration. Emergency cesarean section birth was associated with 1-hour shorter sleep duration at three months compared to vaginal birth [without intrapartum antibiotic prophylaxis] (β: -0.99 h; 95% CI: -1.51, -0.48). Thirty percent of the effect of lower maternal education on infant total sleep duration was mediated sequentially through prenatal depression and birth mode (Total Indirect Effects: -0.12, 95% CI: -0.22, -0.03, p < 0.05)., Conclusions: Prenatal depression and birth mode sequentially mediate the effect of maternal education on infant sleep duration., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: Childhood sleep-disordered breathing (SDB) symptoms may comprise multiple phenotypes depending on craniofacial anatomy, tonsil and adenoid growth, body habitus, and rhinitis symptoms. The primary objective of this study is to identify and characterize the different SDB phenotypes to two years of age., Methods: Data from 770 infants in the Edmonton sub-cohort of the Canadian Healthy Infant Longitudinal Study (CHILD) were analyzed to identify SDB phenotypes based on age of onset and duration of symptoms. Parents completed the 22-item sleep-related breathing disorder (SRBD) scale. Children with a SRBD ratio greater than 0.33 were considered positive for SDB at each quarterly assessment between three months and two years. The STATA Proc trajectory extension identified SDB phenotypes based on their age of onset and duration of symptoms and attributed the percentage chance of a participant being assigned to each phenotype. Multivariate linear regression identified factors associated with increased risk of being assigned to each SDB phenotype., Results: Trajectory analysis identified four phenotypes: no SDB (65.7%), early-onset SDB (15.7%) with peak symptoms at nine months, late-onset SDB (14.2%) with peak symptoms at 18 months, and persistent SDB (5.3%) with symptoms from 3 to 24 months. Rhinitis was associated with all three SDB symptom trajectories (p < 0.05). Children with gastroesophageal reflux disease presented with early (p = 0.03) and late SDB (p < 0.001). Maternal obstructive sleep apnea syndrome (OSAS) was associated with persistent (p = 0.01) and late SDB (p < 0.001). Atopy (positive skin prick test at one year) was associated with persistent SDB (p = 0.04). Infants born prior to 36.5 weeks gestational age were more likely to present with late SDB (p = 0.03)., Conclusion: Childhood SDB symptoms, rather than being a homogenous disorder, may comprise multiple overlapping phenotypes each with unique risk factors., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Both short sleep duration and sleep-disordered breathing (SDB) are associated with poor neurocognitive development. However, the co-contributions of short sleep duration and SDB on neurodevelopment in pre-school children are relatively unknown., Methods: We assessed both sleep duration and SDB by quarterly questionnaire from three months to two years of age among Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort participants. Group-based modeling determined trajectories of total, daytime, and nighttime sleep duration and SDB. Linear regression was used to assess the impact of sleep duration and SDB trajectories on cognitive (primary outcome) and language (secondary) development at two years of age as assessed by the Bayley Scale of Infant Development (BSID-III) (mean 100; standard deviation of 15)., Results: Of the 822 CHILD Edmonton participants, 703 (86%) were still enrolled at two years of age with 593 having BSID-III data at two years of age. Trajectory analysis identified four total sleep durations phenotypes [short sleepers (17.9%), decline to short sleepers (21.1%), intermediate sleepers (36.9%) and long sleepers (24.1%)]. Compared to children with intermediate sleep durations, short sleepers had a 5.2-point lower cognitive development score at two years of age [standard error (SE) 1.7; p = 0.002]. Nocturnal sleep duration, compared to daytime sleep duration had the greatest effect on cognitive development. We also identified three SDB symptom trajectories [early-onset SDB (15.7%), late-onset SDB (14.2%), and persistent SDB (5.3%)] and 79.5% of children had no SDB symptoms. Children with persistent SDB also had a 5.3-point lower language score (SE 2.7; p = 0.05) compared to children with no SDB. SDB trajectories were not associated with cognitive development., Conclusion: In a population-representative birth cohort study, both short sleep duration and SDB were associated with adverse neurodevelopment at two years of age. Children with short nighttime sleep duration had lowered cognitive and language scores and children with persistent SDB also had lower language scores., (Copyright © 2018 Elsevier B.V. All rights reserved.)