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BackgroundDichlorodiphenyltrichloroethane (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.MethodsWe 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.ResultsWe 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.ConclusionsInverse 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.

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.MethodsWe 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.ResultsMaternal 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 (βcis-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 (β = -0.4%, 95% CI = -0.8,-0.0).ConclusionsGestational exposure to pyrethroids may reduce adiposity in children at 5 years of age.

For longitudinal studies with multivariate observations, we propose statistical methods to identify clusters of archetypal subjects by using techniques from functional data analysis and to relate longitudinal patterns to outcomes. We demonstrate how this approach can be applied to examine associations between multiple time-varying exposures and subsequent health outcomes, where the former are recorded sparsely and irregularly in time, with emphasis on the utility of multiple longitudinal observations in the framework of dimension reduction techniques. In applications to children's growth data, we investigate archetypes of infant growth patterns and identify subgroups that are related to cognitive development in childhood. Specifically, "Stunting" and "Faltering" time-dynamic patterns of head circumference, body length and weight in the first 12 months are associated with lower levels of long-term cognitive development in comparison to "Generally Large" and "Catch-up" growth. Our findings provide evidence for the statistical association between multivariate growth patterns in infancy and long-term cognitive development.

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. [ABSTRACT FROM AUTHOR]

Maternal psychosocial distress is conceptualized as an important factor underlying the association between neighborhood deprivation and pregnancy outcomes. However, empirical studies to examine effects of neighborhood deprivation on psychosocial distress during pregnancy are scant. Based on a large multicenter cohort of pregnant women in Montreal, we examined (1) the extent to which psychosocial distress is clustered at the neighborhood-level, (2) the extent to which the clustering is explained by neighborhood material or social deprivation, and (3) whether associations between neighborhood deprivation and psychosocial distress persist after accounting for neighborhood composition (individual-level characteristics) using multilevel analyses. For 5,218 women residing in 740 neighborhoods, a prenatal interview at 24-26 gestational weeks measured both general and pregnancy-related psychological distress using well-validated scales: perceived stress, social support, depressive symptoms, optimism, commitment to the pregnancy, pregnancy-related anxiety, and maternal locus-of-control. Neighborhood deprivation indices were linked to study participants by their residential postal code. Neighborhood-level clustering (intraclass correlation) ranged from 1 to 2 % for perceived stress (lowest), optimism, pregnancy-related anxiety, and commitment to pregnancy to 4-6 % for perceived social support, depressive symptoms, and maternal locus of control (highest). Neighborhood material deprivation explained far more of the clustering (23-75 %) than did social deprivation (no more than 4 %). Although both material and social deprivation were associated with psychological distress in unadjusted analyses, the associations disappeared after accounting for individual-level socioeconomic characteristics. Our results highlight the importance of accounting for individual-level socioeconomic characteristics in studies of potential neighborhood effects on maternal mental health., Author(s): Seungmi Yang[sup.1] [sup.2] , Yan Kestens[sup.3] , Mourad Dahhou[sup.1] , Mark Daniel[sup.4] , Michael S. Kramer[sup.1] [sup.2] Author Affiliations: (1) Department of Pediatrics, Research Institute of McGill University Health [...]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background Evidence on the long-term effect of breastfeeding on neurocognitive development is based almost exclusively on observational studies. In the 16-year follow-up study of a large, cluster-randomized trial of a breastfeeding promotion intervention, we evaluated the long-term persistence of the neurocognitive benefits of the breastfeeding promotion intervention previously observed at early school age. Methods and findings A total of 13,557 participants (79.5% of the 17,046 randomized) of the Promotion of Breastfeeding Intervention Trial (PROBIT) were followed up at age 16 from September 2012 to July 2015. At the follow-up, neurocognitive function was assessed in 7 verbal and nonverbal cognitive domains using a computerized, self-administered test battery among 13,427 participants. Using an intention-to-treat (ITT) analysis as our prespecified primary analysis, we estimated cluster- and baseline characteristic-adjusted mean differences between the intervention (prolonged and exclusive breastfeeding promotion modelled on the Baby-Friendly Hospital Initiative) and control (usual care) groups in 7 cognitive domains and a global cognitive score. In our prespecified secondary analysis, we estimated mean differences by instrumental variable (IV) analysis to account for noncompliance with the randomly assigned intervention and estimate causal effects of breastfeeding. The 16-year follow-up rates were similar in the intervention (79.7%) and control groups (79.3%), and baseline characteristics were comparable between the two. In the cluster-adjusted ITT analyses, children in the intervention group did not show statistically significant differences in the scores from children in the control group. Prespecified additional adjustment for baseline characteristics improved statistical precision and resulted in slightly higher scores among children in the intervention for verbal function (1.4 [95% CI 0.3-2.5]) and memory (1.2 [95% CI 0.01-2.4]). IV analysis showed that children who were exclusively breastfed for [greater than or equal to]3 (versus Conclusions We observed no benefit of a breastfeeding promotion intervention on overall neurocognitive function. The only beneficial effect was on verbal function at age 16. The higher verbal ability is consistent with results observed at early school age; however, the effect size was substantially smaller in adolescence. PROBIT trial registration ClinicalTrials.gov NCT01561612, Author(s): Seungmi Yang 1,*, Richard M. Martin 2,3, Emily Oken 4, Mikhail Hameza 5, Glen Doniger 6, Shimon Amit 6, Rita Patel 2, Jennifer Thompson 4, Sheryl L. Rifas-Shiman 4, [...]

Objectives. We assessed life expectancy increases in the past several decades in South Korea by age and specific causes of death, Methods. We applied Arriaga's decomposition method to life table data (19702005) and mortality statistics (1983-2005) to estimate age-and cause-specific contributions to changes in life expectancy. Results. Reductions in infant mortality made the largest age-group contribution to the life expectancy increase. Reductions in cardiovascular diseases (particularly stroke and hypertensive diseases) contributed most to longer life expectancy between 1983 and 2005 (30% in males and 28% in females). Lower rates of stomach cancer, liver disease, tuberculosis, and external-cause mortality accounted for 30% of the male and 20% of the female increase in longevity. However, higher mortality from ischemic heart disease, lung and bronchial cancer, colorectal cancer, breast cancer, diabetes, and suicide offset gains by 10% in both genders. Conclusions. Rapid increases in life expectancy in South Korea were mostly achieved by reductions in infant mortality and in diseases related to infections and blood pressure. (Am J Public Health. 2010;100:896-903. doi: 10.2105/AJPH.2009.160341)

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. [ABSTRACT FROM AUTHOR]

Objectives. We examined whether socioeconomic inequalities in smoking and overweight and obesity emerged in early adulthood and the contribution of family background, adolescent smoking, and body mass index to socioeconomic inequalities. Methods. Using data from the National Longitudinal Study of Adolescent Health we employed multinomial regression analyses to estimate relative odds of heavy or light-to-moderate smoking to nonsmoking and of overweight or obesity to normal weight. Results. For smoking, we found inequalities by young adult socioeconomic position in both genders after controlling for family background and smoking during adolescence. However, family socioeconomic position was not strongly associated with smoking in early adulthood. For overweight and obesity, we found socioeconomic inequalities only among women both by young adult and family socioeconomic position after adjusting for birthweight, other family background, and body mass index during adolescence. Conclusions. Socioeconomic inequalities in smoking emerged in early adulthood according to socioeconomic position. Among women, inequalities in overweight or obesity were already evident by family socioeconomic position and strengthened by their own socioeconomic position. The relative importance of family background and current socioeconomic circumstances varied between smoking and overweight or obesity. (doi:10.2105/AJPH.2007.111609)

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. [ABSTRACT FROM AUTHOR]