Birth and postnatal outcomes among infants of immigrant parents of different admission categories and parents born in Canada: a population-based retrospective study.

BACKGROUND: Most studies of disparities in birth and postnatal outcomes by parental birthplace combine all immigrants into a single group. We sought to evaluate heterogeneity among immigrants in Canada by comparing birth and postnatal outcomes across different immigration categories. METHODS: We conducted a population-based retrospective study using Statistics Canada data on live births and stillbirths (1993-2017) and infant deaths (1993-2018), linked to parental immigration data (1960-2017). We classified birthing parents as born in Canada, economic-class immigrants, family-class immigrants, or refugees, and evaluated differences in preterm births, small-for-gestational-age (SGA) and large-for-gestational-age (LGA) births, stillbirths, and infant deaths among singleton births by group. RESULTS: Among 7 980 650 births, 1 715 050 (21.5%) were to immigrants, including 632 760 (36.9%) in the economic class, 853 540 (49.8%) in the family class, and 228 740 (13.4%) refugees. Compared with infants of Canadian-born birthing parents, infants of each of the 3 immigrant groups had higher risk of preterm birth, SGA birth, and stillbirth, but lower risk of LGA birth and neonatal death. Compared with infants of economic-class immigrants, infants of refugees had higher risk of early preterm birth (0.9% v. 0.8%, adjusted risk ratio [RR] 1.08, 95% confidence interval [CI] 1.01-1.15) and LGA birth (9.2% v. 7.5%, adjusted RR 1.12, 95% CI 1.10-1.15), but lower risk of SGA birth (10.2% v. 11.0%, adjusted RR 0.92, 95% CI 0.90-0.94), while infants of family-class immigrants had higher risk of SGA birth (12.2% v. 11.0%, adjusted RR 1.01, 95% CI 1.00-1.02). Risk of stillbirth, neonatal death, and overall infant death did not differ significantly among immigrant groups. INTERPRETATION: Heterogeneity exists in outcomes of infants born to immigrants to Canada across immigration categories. These results highlight the importance of disaggregating immigrant populations in studies of health disparities.

Fifty years of evidence on perinatal experience among refugee and asylum-seeking women in Organization for Economic Co-operation and Development (OECD) countries: A scoping review.

BACKGROUND: Members of the Organization for Economic Co-operation and Development (OECD) play a significant role in hosting and supporting refugees. Refugees and asylum seekers in OECD countries may face unique challenges in accessing perinatal healthcare. These challenges can impact their use of and experience with perinatal health services leading to poor maternal and infant outcomes. This scoping review describes the general trends in perinatal health research among refugees/asylum seekers in OECD countries over the past fifty years (1970 to 2021) as well as summarizes their perinatal experience. METHODS: Databases including Embase and Medline were searched using relevant key words for "refugee/ asylum seeker", "perinatal ", and " OECD countries.". Articles were excluded if they only involved economic migrants or internally displaced persons, conducted in non-OECD countries, only assessed health behaviors and practices during pregnancy (e.g., smoking), or were published in a language other than English. The final list of articles included 82 unique studies. RESULTS: In the 40 years between 1970 and 2009, very few studies (n = 9) examined perinatal health among refugees/ asylum seekers in OECD countries. However, an increasing trend was observed over the past decade. Early studies (1980 to 2009) focused more on traditional perinatal outcomes; however, from 2010 onwards, studies related to perinatal experience were more likely to emerge in the global health literature. Access to timely prenatal care remains a challenge with failure to address the root causes of the problem in several OECD countries including those with a long history of hosting refugees. The limited availability of interpretation services and the lack of a patient-centered approach to care have also interfered with the perceived quality of care. In addition, perceived isolation and the limited social support experienced by this vulnerable population have negatively impacted their perinatal experiences in several OECD countries. CONCLUSION: Refugee/asylum seekers in OECD countries face a number of challenges during the perinatal period. Policy changes and further research are needed to address access barriers and identify specific interventions that can improve their well-being during this critical period.

In utero Exposure to Maternal Diabetes and the Risk of Cerebral Palsy: A Population-based Cohort Study.

BACKGROUND: Evidence on the effects of in utero exposure to maternal diabetes on cerebral palsy (CP) in offspring is limited. We aimed to examine the effects of pregestational (PGDM) and gestational diabetes (GDM) separately on CP risk and the mediating role of increased fetal size. METHODS: In a population-based study, we included all live births in Ontario, Canada, between 2002 and 2017 followed up through 2018 (n = 2,110,177). Using administrative health data, we estimated crude and adjusted associations between PGDM or GDM and CP using Cox proportional hazards models to account for unequal follow-up in children. For the mediation analysis, we used marginal structural models to estimate the controlled direct effect of PGDM (and GDM) on the risk of CP not mediated by large-for-gestational age (LGA). RESULTS: During the study period, 5,317 children were diagnosed with CP (187 exposed to PGDM and 171 exposed to GDM). Children of mothers with PGDM showed an increased risk (hazard ratio [HR]: 1.84 [95% confidence interval (CI): 1.59, 2.14]) after adjusting for maternal sociodemographic and clinical factors. We found no associations between GDM and CP (adjusted HR: 0.91 [0.77, 1.06]). Our mediation analysis estimated that LGA explained 14% of the PDGM-CP association. CONCLUSIONS: In this population-based birth cohort study, maternal pregestational diabetes was associated with increased risk of CP, and the increased risk was not substantially mediated by the increased fetal size.

Prevalence and temporal trends of cerebral palsy in children born from 2002 to 2017 in Ontario, Canada: Population-based cohort study.

AIM: To examine the prevalence and temporal trends of cerebral palsy (CP) overall and by population characteristics. METHOD: We identified 2 110 177 live births born in the province of Ontario, Canada, between 2002 and 2017 using administrative health data and estimated CP prevalence in children aged 0 to 16 years overall and by specific population characteristics. We also examined temporal trends in CP rates - overall and by characteristics - in young children (0-4 years) by their year of birth between 2002 and 2013 (n=1 587 087 live births) to allow for an equal follow-up time (4 years and 364 days) for all children. RESULTS: Overall CP prevalence among children aged 0 to 16 years was 2.52 (95% confidence interval 2.45-2.59) per 1000 live births. CP rates in ages 0 to 4 years peaked at 2.86 in 2007 births, but steadily declined afterwards to 1.94 per 1000 live births in 2013. CP rates were higher in children born preterm, small for gestational age, males, multiples, children with congenital malformations, and in children of young (<20 years), old (≥40 years), primiparous, or grand multiparous (≥4) mothers; differences by these characteristics decreased over time. We observed socioeconomic disparities in CP rates that persisted over time. INTERPRETATION: Despite the decreasing trend of CP rates overall, CP rates varied by the child and maternal characteristics over time. WHAT THIS PAPER ADDS: Overall cerebral palsy (CP) prevalence was 2.5 per 1000 live births among children born from 2002 to 2017. CP prevalence peaked in children born in 2007 then steadily decreased between 2007 and 2013. Changes in CP rates varied over time by child and maternal characteristics. Socioeconomic inequalities in CP persisted and remained stable over the study period.

In Utero Exposure to Maternal Injury and the Associated Risk of Cerebral Palsy.

Importance: Although maternal unintentional injury during pregnancy has shown negative impacts on the mother and fetus, the evidence on its long-term associations with children's neurodevelopment is limited. Objective: To examine the association between maternal unintentional injury and cerebral palsy (CP) in offspring. Design, Setting, and Participants: This was a population-based, longitudinal, cohort study of all in-hospital live births born between April 1, 2002, and March 31, 2017, in a publicly funded health care system setting of Ontario, Canada. Infants born more than 20 weeks' gestation were included and followed up until March 31, 2018. Excluded from the analysis were stillbirths, infants with missing or invalid records, and births with missing or invalid birth characteristics. Data were analyzed from March 1 to June 30, 2021. Exposures: Maternal unintentional injury during pregnancy ascertained based on inpatient or emergency department diagnoses. Main Outcomes and Measures: CP diagnosis between birth and the end of follow-up in 2018 with the CP case definition of a single inpatient or 2 or more outpatient diagnoses at least 2 weeks apart between birth and age 16 years. Results: Of 2 110 177 children included in this study (mean [SD] gestational age, 38.8 [1.9] weeks; 1 082 520 male [51.3%]), 81 281 (3.9%) were exposed in utero to maternal unintentional injury. During a median (IQR) follow-up time of 8 (4-12) years, 5317 children (0.3%) were diagnosed with CP (292 CP cases [5.5%] were exposed to maternal unintentional injury). The mean incidence rates of CP were 4.36 and 2.93 per 10 000 child-years in the exposed and the unexposed group, respectively. Children exposed to maternal unintentional injury had a modest increase in the risk of CP, compared with those unexposed (hazard ratio [HR], 1.33; 95% CI, 1.18-1.50) after adjusting for maternal sociodemographic and clinical characteristics. Severe injuries that resulted in hospitalization and delivery within 1 week from the injury conferred higher risks of CP (adjusted HR, 2.18; 95% CI, 1.29-3.68 and adjusted HR, 3.40; 95% CI, 1.93-6.00, respectively). Results were robust in multiple bias analyses. Conclusions and Relevance: In this Canadian population-based birth cohort study, in utero exposure to maternal unintentional injury was associated with an increased risk of CP, with a higher risk with more severe injuries. These findings fill an important gap in knowledge on the potential role of maternal injury on children's neurodevelopment outcomes. Public health professionals and stakeholders should be aware of these potential long-term consequences on offspring when designing programs and providing recommendations about safety during pregnancy. Early monitoring and developmental assessment of children exposed to maternal injury might be warranted.

Effects of mobile networks and Covid-19 on mobile shopping sales in South Korea.

Covid-19 has driven us abruptly to a new world of contactless society. It also compelled us to use online shopping, especially mobile shopping in South Korea, where the dominant mode of wireless communication was already 4G services when Covid-19 broke out. This paper examines the different roles of mobile networks and the Covid-19 pandemic in transforming mobile shopping submarkets in South Korea by estimating the long-term and short-term effects of these two factors on mobile shopping sales. We used a cointegration and an error correction model to estimate long-term and short-term effects separately. This paper finds that Covid-19 was a major short-term factor affecting sales in mobile shopping submarkets, while mobile network subscribers were a key long-term driving factor of mobile shopping sales growth.

Prenatal exposure to insecticides and child cardiometabolic risk factors in the VHEMBE birth cohort.

As part of malaria control programs, many countries spray dichlorodiphenyltrichloroethane (DDT) or pyrethroid insecticides inside dwellings in a practice called indoor residual spraying that results in high levels of exposure to local populations. Gestational exposure to these endocrine- and metabolism-disrupting chemicals may influence child cardiometabolic health. Methods: We measured the serum concentration of DDT and dichlorodiphenyldichloroethylene (DDE) and urinary concentration of pyrethroid metabolites (cis-DBCA, cis-DCCA, trans-DCCA, 3-PBA) in peripartum samples collected between August 2012 and December 2013 from 637 women participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), a birth cohort study based in Limpopo, South Africa. We applied marginal structural models to estimate the relationship between biomarker concentrations and child-size (height and weight), adiposity (body mass index [BMI], body fat percentage, waist circumference) and blood pressure at 5 years of age. Results: Maternal concentrations of all four pyrethroid metabolites were associated with lower adiposity including reduced BMI z-scores, smaller waist circumferences, and decreased body fat percentages. Reductions in BMI z-score were observed only among children of mothers with sufficient energy intake during pregnancy (ßcis-DCCA, trans -DCCA=-0.4, 95% confidence interval (CI) = -0.7,-0.1; pinteraction=0.03 and 0.04, respectively) but there was no evidence of effect modification for the other measures of adiposity. Maternal p,p'-DDT concentrations were associated with a reduction in body fat percentage (ß = -0.4%, 95% CI = -0.8,-0.0). Conclusions: Gestational exposure to pyrethroids may reduce adiposity in children at 5 years of age.

Prenatal Exposure to Insecticides and Weight Trajectories Among South African Children in the VHEMBE Birth Cohort.

BACKGROUND: Dichlorodiphenyltrichloroethane (DDT) or pyrethroid insecticides are sprayed inside dwellings for malaria vector control, resulting in high exposure to millions of people, including pregnant women. These chemicals disrupt endocrine function and may affect child growth. To our knowledge, few studies have investigated the potential impact of prenatal exposure to DDT or pyrethroids on growth trajectories. METHODS: We investigated associations between gestational insecticide exposure and child growth trajectories in the Venda Health Examination of Mothers, Babies and their Environment, a birth cohort of 751 children born between 2012 and 2013 in South Africa. Based on child weight measured at follow-up and abstracted from medical records, we modeled weight trajectories from birth to 5 years using SuperImposition, Translation and Rotation, which estimated two child-specific parameters: size (average weight) and tempo (age at peak weight velocity). We estimated associations between peripartum maternal concentrations of serum DDT, dichlorodiphenyldichloroethylene, or urinary pyrethroid metabolites and SuperImposition, Translation and Rotation parameters using marginal structural models. RESULTS: We observed that a 10-fold increase in maternal concentrations of the pyrethroid metabolite trans-3-(2,2,-dicholorvinyl)-2,2-dimethyl-cyclopropane carboxylic acid was associated with a 21g (95% confidence interval = -40, -1.6) smaller size among boys but found no association among girls (Pinteraction = 0.07). Estimates suggested that pyrethroids may be associated with earlier tempo but were imprecise. We observed no association with serum DDT or dichlorodiphenyldichloroethylene. CONCLUSIONS: Inverse associations between pyrethroids and weight trajectory parameters among boys are consistent with hypothesized disruption of androgen pathways and with our previous research in this population, and support the endocrine-disrupting potential of pyrethroids in humans.

Socio-demographic associations with pregnancy loss among Bakiga and Indigenous Batwa women in Southwestern Uganda.

OBJECTIVE: To assess the extent of pregnancy loss (i.e., miscarriage and/or stillbirth) and examine its association with socio-demographic characteristics among Bakiga and Indigenous Batwa women in Kanungu District, southwest Uganda. METHODS: As part of a larger community-based, participatory project, a retrospective survey of maternal health histories was conducted in ten Batwa and ten Bakiga communities (n = 555 participants) collecting data on self-reported pregnancy loss (i.e., miscarriage and stillbirth) and socio-demographic characteristics. Socio-demographic associations with pregnancy loss (i.e., total miscarriages and stillbirths) were examined using multivariable Poisson and negative binomial regression. RESULTS: Batwa women experienced pregnancy loss more commonly than Bakiga women did (149.8/1000 vs. 96.3/1000 pregnancies). In the final adjusted model for Batwa women, being in the middle (RR 1.92; CI: 1.21-3.07) and highest (RR 1.79; CI: 1.14-2.82) wealth tertiles (compared to lowest wealth tertile) and living in Community X (RR 4.33; CI 2.27-8.28) (compared to all other communities) were associated with increased pregnancy loss. For Bakiga women, the proportion of pregnancy loss was higher for those who reported drinking alcohol during pregnancy (RR: 1.54; CI: 1.04-2.13) and being food insecure (RR 1.39; CI: 1.02-1.91). CONCLUSION: The proportion of, and the socio-demographic associations with, pregnancy loss differed for Bakiga and Indigenous Batwa women. These differences underscore the importance of collecting Indigenous health data to understand not only the extent of, but also the varied contextual circumstances that are associated with pregnancy loss. This nuanced and stratified information is critical for planning meaningful health programming to reduce pregnancy loss for Indigenous women.

Differences in birthweight by maternal and paternal nativity status in Canada.

BACKGROUND: Parental nativity, as well as duration of residence of foreign-born parents in the host country, has been shown to be associated with size at birth. However, most studies have focused on maternal nativity status only and have not accounted for important characteristics of both parents. OBJECTIVE: To explore whether maternal and paternal nativity and length of residence (LOR) are independently associated with birthweight for gestational age in a representative sample of infants in Canada. METHODS: We compared mean differences in sex- and gestational age-standardised birthweight z-score by nativity status of both parents in a nationally representative sample of 130,532 singleton infants born between May 2004 and May 2006 to mothers residing in Canada. We categorised parental nativity status into four groups (both parents Canada-born, mother only foreign-born, father only foreign-born and both parents foreign-born) and parents' LOR into three (both ≤10 years, only one parent ≤10 years and both >10 years). We estimated mean differences in birthweight z-score and their 95% confidence intervals in linear regression models adjusted for parity, parents' ages, education, ethnicity and marital status of the mother. RESULTS: Compared with babies of Canada-born couples, those of two foreign-born parents had on average smaller birthweight z-score, -0.23 (95% CI -0.28, -0.25). However, after adjustment, the mean difference in z-score was -0.02 (95% CI -0.05, 0.00). Infants born to parents who had both resided in Canada for ≤10 years had a unadjusted mean difference in z-score of -0.27 (95% CI -0.29, -0.26), compared infants whose parents were both Canada-born, but the difference became negligible (-0.02, 95% CI -0.04, 0.01) after adjustment. CONCLUSION: The birthweight differences by parental nativity or length of residence observed in our study population could be attributed to differences in the distribution of other parental characteristics that affect birthweight.

Are Indigenous research principles incorporated into maternal health research? A scoping review of the global literature.

BACKGROUND: Indigenous women world-wide are diverse and heterogenous, yet many have similar experiences of colonization, land dispossession, and discrimination. These experiences along with inequitable access to, and quality of, maternal healthcare increase adverse maternal health outcomes. To improve health outcomes for Indigenous women, studies must be conducted with Indigenous involvement and reflect Indigenous research principles. Objectives/Aim: The aim of this review was to explore the range, extent, and nature of Indigenous maternal health research and to assess the reporting of Indigenous research principles in the global Indigenous maternal health literature. METHODS: Following a systematic scoping review protocol, four scholarly electronic databases were searched. Articles were included if they reported empirical research published between 2000 and 2019 and had a focus on Indigenous maternal health. Descriptive data were extracted from relevant articles and descriptive analysis was conducted. Included articles were also assessed for reporting of Indigenous research principles, including Indigenous involvement, context of colonization, Indigenous conceptualizations of health, community benefits, knowledge dissemination to participants or communities, and policy or intervention recommendations. RESULTS: Four-hundred and forty-one articles met the inclusion criteria. While studies were conducted in all continents except Antarctica, less than 3% of articles described research in low-income countries. The most researched topics were access to and quality of maternity care (25%), pregnancy outcome and/or complications (18%), and smoking, alcohol and/or drug use during pregnancy (14%). The most common study design was cross-sectional (49%), and the majority of articles used quantitative methods only (68%). Less than 2% of articles described or reported all Indigenous research principles, and 71% of articles did not report on Indigenous People's involvement. CONCLUSIONS: By summarizing the trends in published literature on Indigenous maternal health, we highlight the need for increased geographic representation of Indigenous women, expansion of research to include important but under-researched topics, and meaningful involvement of Indigenous Peoples.

Effects of maternal exposure to acute stress on birth outcomes: a quasi-experiment study.

Numerous studies have shown associations between maternal stress and poor birth outcomes, but evidence is unclear for causal inference. Natural disasters provide an opportunity to study effects of quasi-randomized hardship with an accurate measure of onset and duration. In a population-based quasi-experimental study, we examined the effect of maternal exposure to the January 1998 Québec ice storm on birth outcomes by comparing pregnant mothers who lived in an area hard hit by the ice storm with those in two unaffected regions. In a total of 147,349 singleton births between 1995 and 2001, we used a difference-in-differences method to estimate the effects of the ice storm on gestational age at delivery (GA), preterm birth (PTB), weight-for-gestational-age z-scores (BWZ), large for gestational age (LGA), and small for gestational age (SGA). After adjusting for maternal and sociodemographic characteristics, there were no differences between the exposed and the unexposed mothers for birth outcomes. The estimated differences (exposed vs. unexposed) were 0.01 SDs (95% CI: -0.02, 0.05) for BWZ; 0.10% point (95% CI: -0.95%, 1.16%) for SGA; 0.25% point (95% CI: -0.78%, 1.28%) for LGA; -0.01 week (95% CI: -0.07, 0.05) for GA; and 0.16% point (95% CI: -0.66%, 0.97%) for PTB. Neither trimester-specific nor dose-response associations were observed. Overall, exposure to the 1998 Québec ice storm as a proxy for acute maternal stress in pregnancy was not associated with poor birth outcomes. Our results suggest that acute maternal hardship may not have a substantial effect on adverse birth outcomes.

Analysis of Maternal Prenatal Weight and Offspring Cognition and Behavior: Results From the Promotion of Breastfeeding Intervention Trial (PROBIT) Cohort.

Importance: Prenatal experiences can influence fetal brain development. Objective: To examine associations of maternal prenatal body mass index (BMI) with cognition and behavior of offspring born full-term. Design, Setting, and Participants: This cohort study examined follow-up data from a breastfeeding promotion intervention at 31 hospitals and affiliated polyclinics in the Republic of Belarus. Participants included 11 276 children who were evaluated from birth (1996-1997) to adolescence (2017-2019), with maternal BMI information available in prenatal medical records. Exposures: Maternal BMI, calculated as weight in kilograms divided by height in meters squared, after 35 weeks gestation; secondary analyses examined maternal BMI at other time points and paternal BMI. Main Outcomes and Measures: Trained pediatricians assessed child cognition with the Wechsler Abbreviated Scales of Intelligence (WASI) at 6.5 years and the computerized self-administered NeuroTrax battery at 16 years, both with an approximate mean (SD) of 100 (15). Parents and teachers rated behaviors at 6.5 years using the Strengths and Difficulties Questionnaire (SDQ, range 0-40). Mixed-effects linear regression analyses corrected for clustering, adjusted for the randomized intervention group and baseline parental sociodemographic characteristics, and were considered mediation by child BMI. Results: Among 11 276 participants, 9355 women (83%) were aged 20 to 34 years, 10 128 (89.8%) were married, and 11 050 (98.0%) did not smoke during pregnancy. Each 5-unit increase in of maternal late-pregnancy BMI (mean [SD], 27.2 [3.8]) was associated with lower offspring WASI performance intelligence quotient (IQ) (-0.52 points; 95% CI, -0.87 to -0.17 points) at 6.5 years and lower scores on 5 of 7 NeuroTrax subscales and the global cognitive score at 16 years (-0.67 points; 95% CI, -1.06 to -0.29 points). Results were similar after adjustment for sociodemographic characteristics, pregnancy complications, and paternal BMI and were not mediated by child weight. Higher late pregnancy maternal BMI was also associated with more behavioral problems reported on the SDQ by teachers but not associated with parent-reported behaviors (externalizing behaviors: 0.13 points; 95% CI, 0.02 to 0.24 points; and total difficulties: 0.14 points, 95% CI, -0.02 to 0.30 points). Results were similar for maternal BMI measured in the first trimester or postpartum. In contrast, higher 6.5-year paternal BMI was associated with slightly better child cognition (WASI verbal IQ: 0.42 points; 95% CI, 0.02 to 0.82 points; NeuroTrax executive function score: 0.68 points; 95% CI, 0.24 to 1.12 points) and fewer teacher-reported behavioral problems (total difficulties: -0.29 points; 95% CI, -0.46 to -0.11 points). Conclusions and Relevance: This cohort study supports findings from animal experiments and human observational studies in settings with higher maternal BMI and obesity rates. Higher maternal prenatal BMI may be associated with poorer offspring brain development, although residual confounding cannot be excluded.

Effect of preschool childcare on school-aged children's adiposity in Quebec, Canada.

BACKGROUND: Regulated public childcare must follow nutrition and physical activity guidelines, but the impact of public childcare on childhood adiposity is unclear. OBJECTIVES: To estimate the effects of universal preschool childcare on children's BMI in elementary school in Quebec, Canada, and whether the effects differed in children from more or less advantaged families. METHODS: For 1657 children enrolled in the Quebec Longitudinal Study of Child Development (1998-2010), BMI z-scores (BMIz) from 6 to 13 years were regressed on the childcare used from 2 to 5 years, adjusted for pre-childcare variables. Average treatment effects were estimated using the Bayesian multilevel linear regression and g-computation for four childcare profiles: 1) parental care or full-time care (35 hours/week) in a 2) centre-based, 3) regulated home-based or 4) unregulated home-based arrangement. RESULTS: Had all participants attended centre-based care, mean BMIz in kindergarten would have been 0.38 (95% credible interval [CrI] 0.23, 0.52), which was 0.40 (95% CrI 0.14, 0.65) SD higher than regulated home-based, 0.20 (95% CrI -0.04, 0.43) SD higher than unregulated home-based and 0.36 (95% CrI 0.11, 0.60) SD higher than parental care. By 12 years, mean BMIz had increased for all childcare profiles, but differences between childcare profiles had diminished. CONCLUSIONS: Although centre-based childcare was associated with an earlier rise in BMI, compared with informal care, it had no large, enduring effect, overall, or for less advantaged children, in particular.

Impacts of universal childcare on early behavioral development: evidence from a birth cohort in Québec, Canada.

PURPOSE: To examine associations between universal pre-school childcare use and later behaviors among children at age 6 years. METHODS: Using annual follow-up data of a birth cohort (N=1450), we estimated differences in behavioral scores by primary childcare arrangement between ages 2-5 years - universal subsidized childcare program (CPE care), non-CPE childcare, and parental or family care (no regular care) - using propensity score inverse probability weights. RESULTS: Teachers reported slightly higher levels of hyperactivity (0.73, 95% CI: 0.32, 1.1) and indirect aggression (0.58, 95%CI: 0.24, 0.91) among children who attended a CPE than children in non-CPE care. However, these patterns were not observed from either maternal or paternal reports. Similarly, teachers' assessments of slightly higher physical aggression (0.50, 95% CI: 0.11, 0.88) and opposition (0.63, 95% CI: 0.21, 1.05) scores among children in CPE care than children who did not have a regular childcare were not observed in parental assessments. Behavioral scores by childcare arrangement were similar between girls and boys and across family socioeconomic position. CONCLUSIONS: Universal pre-school childcare does not appear to have substantial impacts on child behaviors at early school age, however teachers rated externalizing behaviors to be slightly higher among children who attended universal childcare.

Housing conditions and adverse birth outcomes among Indigenous people in Canada.

OBJECTIVES: Poor housing conditions and household crowding have been identified as important health concerns for Indigenous populations in many countries but have not been explored in relation to adverse birth outcomes in these populations. We investigated housing conditions and adverse birth outcomes in a nationally representative sample of Indigenous people in Canada. METHODS: Data were from a cohort of births between May 2004 and May 2006 created by linking birth and infant death registration data with the 2006 Canadian census. Log-binomial regression was used to examine associations between housing variables (persons per room and needed household repairs) and three adverse birth outcomes: preterm birth (PTB), small-for-gestational-age (SGA) birth, and infant mortality. Separate regression models were run for First Nations, Métis and Inuit mothers, with adjustment for parity and parental socio-economic variables. RESULTS: Need for major household repairs was associated with a slightly increased risk of PTB among First Nations and Métis mothers (adjusted RRs 1.12 and 1.13, respectively; 95% CI 0.94-1.34 and 0.89-1.44, respectively) and a moderately increased risk of infant death in all three groups (aRR = 1.69, 95% CI 1.00-2.85). Household crowding was also associated with a slightly elevated risk of PTB in all three groups (aRR = 1.10, 95% CI 0.95-1.29) and with an increased risk of infant mortality among First Nations (aRR = 1.57, 95% CI 0.97-2.53). CONCLUSION: This study highlights the need to improve understanding of links between housing conditions and perinatal health outcomes in Indigenous populations, including examining cause-specific infant mortality in relation to housing characteristics.

RéSUMé: OBJECTIF: Les mauvaises conditions de logement et le surpeuplement ont été identifiés dans plusieurs pays comme étant des enjeux importants de santé chez les populations autochtones. Cependant, aucune étude n'a exploré les conditions de logement en lien avec les issues défavorables de la grossesse dans ces populations. C'est ce que nous avons examiné dans une cohorte de naissances de mères autochtones au Canada, représentative à l'échelle nationale. MéTHODES: Nous avons analysé une cohorte de naissances survenues entre mai 2004 et mai 2006. Cette cohorte a été créée en couplant les données d'enregistrement des naissances et des décès avec les données du Recensement du Canada de 2006. Nous avons utilisé une régression binomiale logarithmique pour estimer les associations entre les conditions de logement (nombre de personnes par chambre et besoins de réparation du logement) et les taux de trois issues défavorables de la grossesse (naissance prématurée, les nouveau-nés petits pour l'âge gestationnel et la mortalité infantile). Des modèles séparés ont été construits pour les femmes des Premières Nations, inuites et métisses, en ajustant les analyses pour la parité et les variables socioéconomiques parentales. RéSULTATS: Les besoins de réparation du logement ont été associés avec un risque ajusté légèrement augmenté de naissance prématurée parmi les mères des Premières Nations et métisses (RRs ajustés : 1,12 et 1,13, respectivement; IC de 95 % : 0,94, 1,34 et 0,89, 1,44, respectivement) et avec un risque modérément élevé de la mortalité infantile dans les trois groupes (RRa = 1,69, IC de 95 % : 1,00, 2,85). Le surpeuplement du logement a été associé avec un risque légèrement augmenté de la naissance prématurée dans les trois groupes (RRa = 1,10, IC de 95 % : 0,95, 1,29) et avec un risque élevé de la mortalité infantile parmi les Premières Nations (RRa = 1,57, IC de 95 % : 0,97, 2,53). CONCLUSION: Cette étude souligne le besoin d'améliorer notre connaissance des liens entre les conditions du logement et les issues de la santé périnatale au sein des populations autochtones, y compris l'étude de la mortalité infantile par cause en association avec les conditions de logement.

A novel development indicator based on population-average height trajectories of children aged 0-5 years modelled using 145 surveys in 64 countries, 2000-2018.

INTRODUCTION: Children's growth status is an important measure commonly used as a proxy indicator of advancements in a country's health, human capital and economic development. We aimed to assess the feasibility of using Super-Imposition by Translation And Rotation (SITAR) models for summarising population-based cross-sectional height-by-age data of children under 5 years across 64 countries. METHODS: Using 145 publicly available Demographic and Health Surveys of children under 5 years across 64 low-income and middle-income countries from 2000 to 2018, we created a multicountry pseudo-longitudinal dataset of children's heights. RESULTS: SITAR models including two parameters (size and intensity) explained 81% of the between-survey variation in mean boys' height and 80% in mean girls' height. Size parameters for boys and girls (relative to the WHO child growth standards) were distributed non-normally around a mean of -5.2 cm for boys (range: -7.9 cm to -1.6 cm) and -4.9 cm for girls (range: -7.7 cm to -1.2 cm). Boys exhibited 10% slower linear growth compared with the WHO (range: 19.7% slower to 1.6% faster) and girls 11% slower linear growth compared with the WHO (range: 21.4% slower to 1.0% faster). Variation in the SITAR size parameter was ≥90% explained by the combination of average length within the first 60 days of birth (as a proxy for fetal growth) and intensity, regardless of sex, with much greater contribution by postnatal intensity (r≥0.89 between size and intensity). CONCLUSIONS: SITAR models with two random effects can be used to model child linear growth using multicountry pseudo-longitudinal data, and thereby provide a feasible alternative approach to summarising early childhood height trajectories based on survey data. The SITAR intensity parameter may be a novel indicator for specifically tracking progress in the determinants of postnatal growth in low-income and middle-income countries.

Early childhood growth trajectory and later cognitive ability: evidence from a large prospective birth cohort of healthy term-born children.

BACKGROUND: Most studies of associations between child growth and cognitive ability were based on size at one or two ages and a single measure of cognition. We aimed to characterize different aspects of early growth and their associations with cognitive outcomes in childhood through adolescence. METHODS: In a sample of 12 368 Belarusian children born at term, we examined associations of length/height and weight trajectories over the first 6.5 years of life with cognitive ability at 6.5 and 16 years and its change over time. We estimated growth trajectories using two random-effects models-the SuperImposition by Translation and Rotation to model overall patterns of growth and the Jenss-Bayley to distinguish growth in infancy from post infancy. Cognitive ability was measured using the Wechsler Abbreviated Scales of Intelligence at 6.5 years and the computerized NeuroTrax test at 16 years. RESULTS: Higher length/height between birth and 6.5 years was associated with higher cognitive scores at 6.5 and 16 years {2.7 points [95% confidence interval (CI): 2.1, 3.2] and 2.5 points [95% CI: 1.9, 3.0], respectively, per standard deviation [SD] increase}. A 1-SD delay in the childhood height-growth spurt was negatively associated with cognitive scores [-2.4 (95% CI: -3.0, -1.8) at age 6.5; -2.2 (95% CI: -2.7, -1.6) at 16 years]. Birth size and post-infancy growth velocity were positively associated with cognitive scores at both ages. Height trajectories were not associated with the change in cognitive score. Similar results were observed for weight trajectories. CONCLUSIONS: Among term infants, the overall size, timing of the childhood growth spurt, size at birth and post-infancy growth velocity were all associated with cognitive ability at early-school age and adolescence.

Linear growth and mid-childhood cognitive outcomes in three birth cohorts of term-born children: an approach to integrating three growth models to explore critical windows.

OBJECTIVE: To illustrate that a mediation framework can help integrate inferences from three growth models to enable a comprehensive view of the associations between growth during specific developmental windows and mid-childhood IQ. DESIGN: We analysed direct and indirect associations between mid-childhood IQ and length/height growth in five early-life age intervals bounded by conception, birth, early, mid and late infancy, and mid-childhood using estimates from three growth models (lifecourse, conditional change and change score) applied to three historical birth cohorts. PARTICIPANTS AND SETTING: 12 088 term-born children from the Collaborative Perinatal Project (CPP) in the USA (n=2170), the Promotion of Breastfeeding Intervention Trial (PROBIT) in Belarus (n=8275) and the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines (n=1643). PRIMARY OUTCOME MEASURE: Mid-childhood IQ. RESULTS: Our analyses revealed cross-cohort and cross-interval variations in the direct and indirect effects of foetal and early childhood physical growth on mid-childhood IQ. For example, in CPP, there was a direct association of prenatal growth with IQ that was not evident in the other cohorts, whereas in PROBIT and CLHNS, we observed that foetal and early growth-IQ associations were mediated through size in later periods. CONCLUSION: Lifecourse, conditional change and change score growth models yield complementary inferences when appropriately interpreted. Future longitudinal studies of associations of early-life growth with later outcomes would benefit from adopting a causal mediation framework to integrate inferences from multiple complementary growth models.