Background/Objectives: Attention Deficit Hyperactivity Disorder (ADHD), one of the most common neurodevelopmental disorders in childhood and adolescence, is associated with obesity in observational studies. However, it is unclear whether ADHD contributes to, results from or is merely correlated with obesity. This study evaluates the presence and direction of a causal effect between ADHD and obesity. Subjects/Methods: We performed a bidirectional two-sample Mendelian randomization using summary data from consortia of genome-wide association studies to investigate if ADHD (N=55 374) has a causal effect on body mass index (BMI) in childhood (N= 35 668) and adulhood (N=322 154 to 500 000), and vice-versa. The main analysis was performed using the Inverse Variance Weighted (IVW) method. As sensitivity analyses, we used other Mendelian randomization methods that are more robust to horizontal pleiotropy (i.e. MR-Egger, weighted mode and penalized weighted median estimators), as well as stratified the analysis by the putative mechanisms of genetic instruments (i.e. pathways involved or not in neurological processes). Results: The IVW method indicated a positive causal effect of BMI on ADHD: β=0.324 (95%CI 0.198 to 0.449, p<0.001; expressed as change in ln(odds ratio) of ADHD per each additional SD unit of BMI). IVW estimates were directionally consistent with other methods. On the other hand, we did not find consistent evidence for a causal effect of ADHD genetic liability on BMI. Conclusions: The results suggested that higher BMI increases the risk of developing ADHD, but not the other way around.

BackgroundLongitudinal studies have consistently reported that prenatal exposure to acetaminophen can to lead to an increased risk of attention deficit-hyperactivity disorder during childhood. This study aimed to investigate the association between intrauterine exposure to acetaminophen and the presence of emotional and behavioral problems at the ages of 6 and 11 years in a low-middle income country.MethodsWe performed a prospective longitudinal population-based study using data from the 2004 Pelotas birth cohort. From the 4231 initial cohort participants, 3722 and 3566 children were assessed at 6 and 11 years of age, respectively. The outcomes were assessed using the parent version of Strengths and Difficulties Questionnaire (SDQ). The cut-off points established for the Brazilian population were used to categorize the outcomes. Crude and adjusted odds ratio were obtained through logistic regression.ResultsAcetaminophen was used by 27.5% (95% confidence interval [CI]: 26.1–28.9) of the mothers at least once during pregnancy. The prevalence of emotional problems at 6 and 11 years was 13.6 and 19.9%, respectively. For hyperactivity problems, prevalence was 13.9 and 16.1%, respectively. Intrauterine exposure to acetaminophen increased the odds of having emotional (odds ratio [OR] = 1.47; 95% CI: 1.07–2.02) and hyperactivity/inattention (OR = 1.42; 95% CI: 1.06–1.92) problems in 6-year-old boys. At the age of 11, a small decrease in the effect was observed for both outcomes after adjustment: OR = 1.31 (95% CI: 0.99–1.73) for emotional problems and OR = 1.25 (95% CI: 0.95–1.65) for hyperactivity/inattention in boys. No association for any phenotypes at both ages was observed for girls.ConclusionThe effect of intrauterine exposure to acetaminophen in emotional and hyperactivity symptoms was dependent on sex in a Brazilian cohort. While it seemed to be important for boys, mainly at 6 years of age, for girls, no association was observed.Electronic supplementary materialThe online version of this article (10.1186/s12888-018-1942-1) contains supplementary material, which is available to authorized users.

Background: Several studies have reported that there is an association between developmental and emotional/behavioural problems in children exposed to acetaminophen during foetal development. However, few studies have focused on development and behavioural outcomes in early life. Objectives:To test the association between prenatal exposure to acetaminophen and low neurodevelopmental performance at 24 months and behavioural/emotional problems at 48 months of life. Methods:We used data from the 2004 Pelotas Birth Cohort, a population-based longitudinal prospective study. Neurodevelopment was evaluated at 24 months using Battelle's Developmental Inventory (BDI) (n = 3737). We assessed global function as well as each domain (personal-social, adaptative, motor, cognitive, and communication). Behavioural/emotional problems were assessed at 48 months using the Child Behaviour Checklist (CBCL) (n = 3624). We used the CBCL total, externalising, and internalising symptomatology and individual subscales (withdrawn, somatic complaints, anxious/depressed, social problems, cognitive problems, attention problems, aggressive behaviour, and rule-breaking behaviour). Acetaminophen use during pregnancy was retrospectively assessed at the perinatal follow-up. Poisson regression and multiple linear regression analyses were used to test the association, adjusting for several family and maternal sociodemographic and health factors, medication use during pregnancy, and the sex of the child.Results: Acetaminophen exposure during prenatal development was not associated with low neurodevelopmental performance at 24 months assessed using the BDI or to emotional and behavioural problems assessed at 48 months using the CBCL in the adjusted models. Conclusions:We cannot confirm the existence of an association between acetaminophen used during pregnancy and low neurodevelopmental performance at 24 months and emotional/behavioural problems at 48 months of life based on the present results. | 279 TOVO-RODRIGUES ET al. S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section. How to cite this article: Tovo-Rodrigues L, Carpena MX, Martins-Silva T, et al. Low neurodevelopmental performance and behavioural/emotional problems at 24 and 48 months in Brazilian children exposed to acetaminophen during foetal development. Paediatr Perinat Epidemiol. 2020;34:278-286.

Objective: To investigate the relationship between ultra-processed food consumption and early childhood caries. Design: Cross-sectional analysis of baseline data from a cluster randomised controlled study. Outcomes included the prevalence of children with non-cavitated and cavitated caries. The main exposure was the total daily consumption of ultra-processed foods (up to three times and four times or more), assessed through a FFQ. Potential confounders were socio-demographic characteristics of the child and caregiver/family, child breast-feeding, oral hygiene and use of dental services. Poisson regression using robust variance adjustment was used to estimate prevalence ratios (PR) and their respective 95 % CI. Setting: Primary Healthcare Centers in an urban area of Pelotas, Southern Brazil. Participants: Children aged 0–3 years (n 309). Results: Consumption of ultra-processed foods four times or more a day was found in 67·6 % of children; 24·4 and 12·0 % presented non-cavitated and cavitated caries, respectively. After adjustment, children who consumed ultra-processed foods four times or more a day were more likely to present both non-cavitated caries (PR 2·25, 95 % CI 1·19, 4·27, P = 0·013) and cavitated caries (PR 3·48, 95 % CI 1·18, 10·30, P = 0·024) compared with those who have consumed them up to three times a day. Conclusions: Consumption of ultra-processed foods is associated with early childhood caries. Interventions aiming at reducing ultra-processed food consumption should be implemented to improve children’s oral health.

Objective: To describe and compare measures of maternal depression, anxiety, and posttraumatic stress symptoms before and during the coronavirus disease 2019 (COVID-19) pandemic in a Brazilian birth cohort. Methods: All hospital births occurring in the municipality of Rio Grande (southern Brazil) during 2019 were identified. Mothers were invited to complete a standardized questionnaire on sociodemographic and health-related characteristics. Between May and July 2020, we tried to contact all cohort mothers of singletons, living in urban areas, to answer a standardized web-based questionnaire. They completed the Edinburgh Postnatal Depression Scale (EPDS) and Generalized Anxiety Disorder 7-item (GAD-7) in both follow-ups, and the Impact of Event Scale (IES) in the online follow-up. Results: We located 1,136 eligible mothers (n=2,051). Of those, 40.5% had moderate to severe stress due to the current pandemic, 29.3% had depression, and 25.9% had GAD. Mothers reporting loss of income during the pandemic (57.2%) had the highest proportions of mental health problems. Compared to baseline, the prevalence of depression increased 5.7 fold and that of anxiety increased 2.4-fold during the pandemic (both p < 0.001). Conclusion: We found a high prevalence of personal distress due to the ongoing COVID-19 pandemic, and a clear rise in both maternal depression and anxiety.