Is an antioxidant-rich or a pro-inflammatory diet during pregnancy associated with allergic and respiratory multimorbidity in children from the ELFE birth cohort?

The antioxidant capacity and the inflammatory potential of diet during pregnancy may represent a prevention opportunity for allergic and respiratory diseases. We aimed to investigate the associations between the antioxidant and inflammatory potential of maternal diet in the last three months of pregnancy with allergic and respiratory diseases in children. Analyses were performed on 9679 mother-child pairs from the ELFE birth cohort. The dietary total antioxidant capacity (DTAC), without coffee, was estimated with the Trolox equivalent antioxidant capacity (TEAC), the total radical trapping antioxidant parameter (TRAP), and the ferric reducing-antioxidant power (FRAP). The inflammatory potential of the maternal diet was assessed by the energy-adjusted Dietary Inflammatory Index (E-DII). Allergic and respiratory diseases in children up to 5.5 years were considered jointly through five allergic and respiratory multimorbidity clusters ("asymptomatic" - reference, "early wheeze without asthma", "asthma only", "allergies without asthma", "multi-allergic"). Multinomial logistic regressions were performed and adjusted for main confounders. A diet with a higher antioxidant potential was associated with a lower risk of belonging to the "early wheeze without asthma" cluster (aOR(95%CI) = 0.95 (0.90;0.99) per standard deviation (SD) of TEAC score). A higher E-DII was associated with a higher risk of belonging to the "asthma only" cluster (aOR(95% CI)= 1.09 (1.00;1.19) per SD). No association was found with the "allergies without asthma" or "multi-allergic" clusters. An antioxidant-rich diet during pregnancy was associated with better respiratory health while a pro-inflammatory diet was associated with poorer respiratory health in children up to 5.5 years, though the associations were weak.

Timing of food pieces introduction and neurodevelopment: findings from a nationwide birth cohort.

BACKGROUND: While complementary feeding can be challenging, little emphasis has been placed on the introduction to food texture/pieces, especially in terms of neurodevelopmental outcomes. This study aims to determine the association between the timing of introduction to food pieces during infancy and neurodevelopment in early childhood. We hypothesized that late introduction to food texture/pieces relates to unfavorable neurodevelopmental outcomes. METHODS: Families (n = 18329) were recruited from the general population during the nationwide ELFE (Étude Longitudinale Française depuis l'Enfance) birth cohort in France, and 8511 were selected for a complete case analysis. Age at introduction to food pieces was determined based on repeated assessments during the first year. A range of neurodevelopmental outcomes among children were assessed using validated instruments, i.e. composite scores at 1 and 3.5 years, and a score for language acquisition at 2 years. Risk for developmental delay at 3.5 years was defined based on a developmental quotient (DQ) below 90 according to the child's chronological age and the respective composite score at this age. We used linear regression modelling to evaluate associations between age at introduction to food pieces and the standardised neurodevelopmental scores, while logistic regression models were used in the analyses according to the risk for developmental delay. RESULTS: Our findings highlight consistent associations between late introduction to food pieces (i.e., after 10 months, compared to early (before 8 months)) and lower estimates of standardised neurodevelopmental scores at ages 1, 2 and 3.5 years (-0.35 [-0.40; -0.30], -0.15 [-0.20; -0.10] and - 0.18 [-0.23; -0.13], respectively). Infants introduced to pieces late were also more likely to be at risk for developmental delay according to DQ < 90 (OR [95%CI] = 1.62 [1.36; 1.94]). CONCLUSIONS: This study shows that late introduction to food pieces (> 10 months) is related to lower neurodevelopmental scores. Given the challenges that complementary feeding may pose, concerted efforts are required to enhance our understanding of the sensory aspects of early diets and to ultimately provide guidance.

Early childcare and developmental delay risk at 3.5 years: Insights from the French ELFE cohort.

We tested the association between early childcare attendance in the first three years of life and child development at age 3.5 years in the French context, where early childcare is subsidized. In the ELFE (Étude Longitudinale Français depuis l'Enfance) birth cohort study set in metropolitan France, children's development was reported by parents at age 3.5 years (n = 11,033) via the Child Development Inventory (CDI) questionnaire. CDI scores were transformed into a development quotient (DQ), with a DQ < 90 corresponding to possible and a DQ < 85 corresponding to a probable developmental delay. Inverse probability weighted multivariable regression models were used to analyse whether early childcare in the first three years of life (centre-based, childminder, informal or parental care) was associated to development delay. Compared to children in exclusive parental care, those in centre-based childcare (CBC) or with a childminder prior to school entry were significantly less likely to experience possible (OR = 0.56, [95% CI = 0.51-0.61] for CBC and OR = 0.77, [95% CI = 0.72-0.83] for childminder attendance) and probable developmental delay (OR = 0.62, [0.58-0.67] for CBC and OR = 0.80 [0.76-0.83] for childminder). Informal childcare attendance was not significantly associated with children's possible nor probable developmental delay ((OR = 0.97, [0.84-1.12]) and (OR = 0.97, [0.82-1.15]), respectively). Conclusions: Overall, our findings add to the existing scientific literature, showing that in the French context, where childcare can start as early as 3 months of age, early childcare attendance can contribute to child's development. What's Known on This Subject: • Studies on early childcare attendance and child development have shown mixed results, associations with better psychomotor development mainly being observed in Nordic countries, while some studies in other countries such as the USA showed no or negative associations. What This Study Adds: • In a country with broad and subsidized access to childcare such as France, access to early childhood education can positively contribute to children's psychomotor development. However, we found that access to childcare does not appear to reduce social inequalities in children's psychomotor development.

Plasma 21-deoxycortisone: a sensitive additive tool in 21-hydroxylase deficiency in newborns.

OBJECTIVE, DESIGN, AND METHODS: Although 17-hydroxyprogesterone (17OHP) has historically been the steroid assayed in the diagnosis of congenital adrenal 21-hydroxylase deficiency (CAH-21D), its C11-hydroxylated metabolite, 21-deoxycortisol (21DF), which is strictly of adrenal origin, is assayed in parallel in this pathology. This steroid (21DF) is oxidized by 11beta-hydroxysteroid dehydrogenase type 2 into 21-deoxycortisone (21DE). In the context of CAH-21D confirmation testing, confounding factors (such as intensive care unit admission, stress, prematurity, early sampling, and variations of sex development) can interfere with the interpretation of the gold-standard biomarkers (17OHP and 21DF). Since its tissue concentrations are especially high in the placenta, we hypothesized that 21DE quantification in the neonatal periods could be an interesting biomarker in addition to 17OHP and 21DF. To verify this hypothesis, we developed a new mass spectrometry-based assay for 21DE in serum and applied it to newborns screened for CAH-21D. RESULTS: In newborns with CAH-21D, the mean serum levels of 21DE reached 17.56 ng/mL (ranging from 8.58 ng/mL to 23.20 ng/mL), and the mean 21DE:21DF ratio was 4.99. In contrast, in newborns without CAH-21D, the 21DE serum levels were low and not statistically different from the analytical 21DE limit of quantification (0.01 ng/mL). CONCLUSION: Basal serum 21DE appears to be a novel sensitive and specific biomarker of CAH-21D in newborns.

Maternal diet quality with child allergic and respiratory multimorbidity in the Elfe birth cohort.

Evidence linking maternal diet during pregnancy to allergic or respiratory diseases in children remains sparse, and outcomes were mainly studied separately. We aim to investigate these associations by considering clusters of allergic and respiratory multimorbidity among 9679 mother-child pairs from the Elfe birth cohort. Maternal diet quality was evaluated using a food-based score (Diet Quality score), a nutrient-based score (PANDiet score) and food group intakes. Adjusted multinomial logistic regressions on allergic and respiratory multimorbidity clusters up to 5.5 years were performed. Child allergic and respiratory diseases were described through five clusters: "asymptomatic" (43%, reference), "early wheeze without asthma" (34%), "asthma only" (7%), "allergies without asthma" (7%), "multi-allergic" (9%). A higher PANDiet score and an increased legume consumption were associated with a reduced risk of belonging to the "early wheeze without asthma" cluster. A U-shaped relationship was observed between maternal fish consumption and the "allergies without asthma" cluster. To conclude, adequate nutrient intake during pregnancy was weakly associated with a lower risk of "early wheeze without asthma" in children. No association was found with food groups, considered jointly or separately, except for legumes and fish, suggesting that maternal adherence to nutritional guidelines might be beneficial for allergic and respiratory diseases prevention.

Associations of screen use with cognitive development in early childhood: the ELFE birth cohort.

BACKGROUND: The associations of screen use with children's cognition are not well evidenced and recent, large, longitudinal studies are needed. We aimed to assess the associations between screen use and cognitive development in the French nationwide birth cohort. METHODS: Time and context of screen use were reported by parents at ages 2, 3.5 and 5.5. Vocabulary, non-verbal reasoning and general cognitive development were assessed with the MacArthur-Bates Communicative Development Inventory (MB) at age 2, the Picture Similarities subtest from the British Ability Scales (PS) at age 3.5 and the Child Development Inventory (CDI) at ages 3.5 and 5.5. Outcome variables were age-adjusted and standardized (mean = 100, SD = 15). Multiple imputations were performed among children (N = 13,763) with ≥1 screen use information and ≥1 cognitive measures. Cross-sectional and longitudinal associations between screen use and cognitive development were assessed by linear regression models adjusted for sociodemographic and birth factors related to the family and children, and children's lifestyle factors competing with screen use. Baseline cognitive scores were further considered in longitudinal analysis. RESULTS: TV-on during family meals at age 2, not screen time, was associated with lower MB scores at age 2 (ß [95% CI] = -1.67 [-2.21, -1.13]) and CDI scores at age 3.5 (-0.82 [-1.31, -0.33]). In cross-sectional analysis, screen time was negatively associated with CDI scores at ages 3.5 (-0.67 [-0.94, -0.40]) and 5.5 (-0.47 [-0.77, -0.16]), and, in contrast, was positively associated with PS scores (0.39 [0.07, 0.71]) at age 3.5. Screen time at age 3.5 years was not associated with CDI scores at age 5.5 years. CONCLUSIONS: Our study found weak associations of screen use with cognition after controlling for sociodemographic and children's birth factors and lifestyle confounders, and suggests that the context of screen use matters, not solely screen time, in children's cognitive development.

SARS-CoV-2 seroprevalence in French 9-year-old children and their parents after the first lockdown in 2020.

Introduction: Children have been significantly less affected by COVID-19 than adults and presented with milder and less symptomatic forms of the disease. However, there has been suggestion that children older than 10 years and adolescents exhibits features closer to that of young adults. Most studies combine children in different age-groups and lack sufficient numbers to explore in detail age specificities. We report data on a population-based sample of 2,555 children at the pivotal age of 9 years. Methods: In April 2020, the participants in two French nationwide cohorts of children, Elfe and Epipage2, were invited to take part into an online survey about Covid related symptoms and family life during the lockdown. A second questionnaire was sent on May 5. This questionnaire also proposed to the child included in the cohort and to one of his/her parents to take part into a capillary blood collection for Covid serology. Families who agreed to the serological survey were sent kits for dried blood spots self-sampling (DBS) with instructions. Samples were processed with a commercial Elisa test (Euroimmun®, Lübeck, Germany) to detect anti-SARS-CoV-2 antibodies (IgG) directed against the S1 domain of the spike protein of the virus. Results: Children's acceptance rate for the serological survey was around 60%. 2,555 serological results were analyzed. The weighted prevalence of a positive Elisa Spike serology was 2.8% in 9 yr-old children (95% CI: 1.7%-4.0%). Positive serology was found in 8.6% (7.4%-9.7%) of parents who provided blood. There was a significant association (p < 0.001) between serology of the child and parent from the same household with an odds ratio of 13.8 (7.9-24.2). Discussion: We have shown that 9-yr old children had a lower susceptibility to SARS-Cov2 infection than adults with the initial Chinese strain, similar to younger children and estimated that around 3% of them have developed antibodies against SARS-Cov2 in France after the first wave of the Covid-19 epidemics.

Longitudinal sleep multi-trajectories from age 1 to 5.5 years and their early correlates: results from the Étude Longitudinale Française depuis l'Enfance birth cohort study.

STUDY OBJECTIVES: To identify sleep multi-trajectories in children from age 1 to 5.5 years and their early correlates. METHODS: We collected early family, maternal, and child characteristics, including children's nighttime sleep duration (NSD) and daytime sleep duration (DSD), night waking (NW), and sleep-onset difficulties (SOD), by parental phone interviews at age 2 months and 1-, 2-, 3.5-, and 5.5 years. Group-based multi-trajectory modeling identified sleep multi-trajectory groups. Multinomial logistic regression assessed associations with early factors. RESULTS: We identified five distinct sleep multi-trajectory groups for NSD, DSD, NW, and SOD in 9273 included children. The "Good sleepers" (31.6%) and "Long sleepers" (31.0%) groups had low NW and SOD prevalence and shorter NSD but longer DSD in "Good sleepers" than in "Long sleepers." The "Good sleepers but few SOD" group (10.3%) had long NSD and DSD but a SOD peak at age 3.5 years; the "Improving NW and SOD" group (9.6%) showed short but rapidly increasing NSD to a plateau and high but decreasing NW and SOD; the "Persistent NW and SOD" group (17.5%) had persistent high NW and SOD. Maternal depression during pregnancy and sleep habits at age 1 (e.g. parental presence or feeding to fall asleep, sleeping at least part of the night away from own bed) were common risk factors associated with the most disordered sleep multi-trajectory groups. CONCLUSIONS: We identified distinct sleep multi-trajectory groups and early life-associated factors in preschoolers. Most of the factors associated with the most sleep-disordered multi-trajectory groups are likely modifiable and provide clues for early prevention interventions.

Child health screening program in French nursery schools: Results and related socioeconomic factors.

Objectives: The study aims to describe the output of routine health screening performed in French nursery schools by the maternal and child health services among children aged 3-4 years and to quantify the level of early socioeconomic health disparities. Methods: In 30 participating départements, data on screening for vision and hearing impairments, overweight and thinness, dental health, language, psychomotor development, and immunizations were collected for children born on specific dates in 2011 and enrolled in nursery school in 2014-2016. Information was collected on the children, their socioeconomic characteristics and on the school attended. Odds of abnormal screening results were compared for each socioeconomic factor by logistic regressions adjusted for age, sex, prematurity and bilingualism. Results: Among the 9,939 children screened, prevalence of disorders was 12.3% for vision, 10.9% for hearing, 10.4% for overweight, 7.3% for untreated caries, 14.2% for language and 6.6% for psychomotricity. Newly detected visual disorders were more frequent in disadvantaged areas. Children with unemployed parents were three time more likely to have untreated caries and twice as likely to present language or psychomotor impairments; 52% were referred to a health professional following screening compared to 39% of children with employed parents. Except for children in disadvantaged areas, vaccine coverage was lower among disadvantaged groups. Conclusion: The prevalences of impairments, which are higher among disadvantaged children, highlight the potential preventive impact of systematic screening under the comprehensive maternal and child healthcare program. These results are important to quantify early socioeconomic inequalities in a Western country known for its generous social welfare system. A more holistic approach to child health is needed with a coherent system involving families and aligning primary care, local child health professionals, general practitioners, and specialists. Further results are needed to evaluate its impact on later child development and health.

Whispers of change in preschool asthma phenotypes: Findings in the French ELFE cohort.

RATIONALE: Early life asthma phenotyping remains an unmet need in pediatric asthma. In France, severe pediatric asthma phenotyping has been done extensively; however, phenotypes in the general population remain underexplored. Based on the course and severity of respiratory/allergic symptoms, we aimed to identify and characterize early life wheeze profiles and asthma phenotypes in the general population. METHODS: ELFE is a general population based birth cohort; which recruited 18,329 newborns in 2011, from 320 maternity units nationwide. Data was collected using parental responses to modified versions of ISAAC questionnaire on eczema, rhinitis, food allergy, cough, wheezing, dyspnoea and sleep disturbance due to wheezing at 3 time points: post-natal (2 months), infancy (age 1) and pre-school (age 5). We built a supervised trajectory for wheeze profiles and an unsupervised approach was used for asthma phenotypes. Chi squared (χ2) test or fisher's exact test was used as appropriate (p < 0.05). RESULTS: Wheeze profiles and asthma phenotypes were ascertained at age 5. Supervised wheeze trajectory of 9161 children resulted in 4 wheeze profiles: Persistent (0.8%), Transient (12.1%), Incident wheezers at age 5 (13.3%) and Non wheezers (73.9%). While 9517 children in unsupervised clusters displayed 4 distinct asthma phenotypes: Mildly symptomatic (70%), Post-natal bronchiolitis with persistent rhinitis (10.2%), Severe early asthma (16.9%) and Early persistent atopy with late onset severe wheeze (2.9%). CONCLUSION: We successfully determined early life wheeze profiles and asthma phenotypes in the general population of France.

Parents' depression and anxiety associated with hyperactivity-inattention and emotional symptoms in children during school closure due to COVID-19 in France.

Several risk factors of children's mental health issues have been identified during the pandemic of COronaVIrus Disease first appeared in 2019 (COVID-19). This study aims to fill the knowledge gap regarding the association between parents' and children's mental health issues during the COVID-19 school closure in France. We conducted a cross-sectional analysis of data collected in the SAPRIS-ELFE study during the COVID-19 pandemic in France. Using multinomial logistic regressions, we estimated associations between parents' and children's mental health issues. Symptoms of anxiety were assessed by the General Anxiety Disorder-7 (GAD-7) and depression by the Patient Health Questionnaire-9 (PHQ-9) for the parents. Hyperactivity/inattention and emotional symptoms in children were assessed by the Strengths and Difficulties Questionnaire (SDQ). The sample included 3496 children aged 8 to 9 years, of whom 50.0% were girls. During the school closure, 7.1% of responding parents had moderate to severe levels of anxiety and 6.7% had moderate to severe levels of depression. A total of 11.8% of the children had an abnormal hyperactivity/inattention score and 6.6% had an abnormal emotional symptoms score. In multivariate regression models, parental moderate to severe level of anxiety and moderate to severe level of depression were associated with abnormal hyperactivity-inattention score (adjusted Odds Ratio (aOR) 3.31; 95% Confidence Interval (CI) 2.33-4.70 and aOR 4.65; 95% CI 3.27-6.59, respectively) and abnormal emotional symptoms score in children (aOR 3.58; 95% CI 2.33-5.49 and aOR 3.78; 95 CI 2.47-5.78 respectively). Children whose parents have symptoms of anxiety and/or depression have an increased likelihood of symptoms of hyperactivity/inattention and emotional symptoms during school closures in France due to COVID-19. Our findings suggest that public health initiatives should target parents and children to limit the impact of such crises on their mental health issues.

Paternity leave uptake and parental post-partum depression: findings from the ELFE cohort study.

BACKGROUND: Several countries are expanding their paternity leave policies, which can have positive effects on parental mental health. We examined whether 2 weeks of paid paternity leave are associated with post-partum depression in mothers and fathers at 2 months after the birth of their child. METHODS: We used data from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort study. Participating mothers gave birth in 2011 in a representative sample of 320 maternity hospitals in mainland France. Inclusion criteria were single or twin livebirths born after at least 33 weeks' gestation; mother's age at least 18 years; no plans to leave metropolitan France within 3 years. Mothers were interviewed face-to-face shortly after the child's birth. Fathers and mothers were both interviewed by telephone 2 months after the child's birth, reporting whether the father had the right to paternity leave and if yes, if he had taken or intended to take it. We used the Edinburgh Postnatal Depression Scale to assess post-partum depression among fathers and mothers at 2 months. Logistic regression models, using survey-weighted data and adjusted for confounders using inverse probability weights, yielded odds ratios (ORs). FINDINGS: We included 10 975 fathers and 13 075 mothers with reported information on paternity leave and post-partum depression at 2 months in the statistical analyses. Fathers had a median age of 32·6 years (IQR 36·9-22·6) and mothers had a median age of 30·5 years (34·0-27·1) at the time of the ELFE child's birth. The prevalence of depression in fathers according to paternity leave status was 4·5% among those who used paternity leave, 4·8% among those who intended to use paternity leave, and 5·7% among those who did not use paternity leave. For mothers, the prevalence of post-partum depression was 16·1% among those whose partner used paternity leave, 15·1% among those whose partner intended to use paternity leave, and 15·3% among those whose partner did not use paternity leave. Fathers who took paternity leave had reduced odds of post-partum depression (OR 0·74 [95% CI 0·70-0·78]) as did fathers who intended to take paternity leave (0·76 [0·70-0·82]) compared with fathers who did not take paternity leave. However, we did not find such beneficial effects for mothers whose partners took (1·13 [1·05-1·20]) or intended to take paternity leave (1·02 [0·96-1·08]). INTERPRETATION: Taking and intending to take 2-weeks' paid paternity leave was associated with a reduced likelihood of reporting post-partum depression in fathers. However, offering 2-weeks' paternity leave might place mothers at a greater risk of post-partum depression, suggesting that optimal length and timing of the leave, among other factors, need further investigation. FUNDING: The French National Research Agency.

Determinants of incomplete vaccination in children at age two in France: results from the nationwide ELFE birth cohort.

Incomplete vaccination in the pediatric population is a growing public health issue in high-income countries, but its determinants are poorly understood. Their identification is necessary to design target actions that can improve vaccination uptake. Our aim was to assess the determinants of incomplete vaccination in two-year-old children in France. Among the 18,329 children included in the 2011 ELFE French nationwide population-based birth cohort, we selected those for whom vaccination status was available at age two years. Incomplete vaccination was defined as ≥ 1 missing dose of recommended vaccines. Potential determinants of incomplete vaccination were identified by using logistic regression, taking into account attrition and missing data. Of the 5,740 (31.3%) children analyzed, 46.5% (95% confidence interval [CI] 44.7-48.0) were incompletely vaccinated. Factors independently associated with incomplete vaccination were having older siblings (adjusted odds ratio 1.18, 95% CI [1.03-1.34] and 1.28 [1.06-1.54] for one and ≥ 2 siblings, respectively, vs. 0), residing in an isolated area (1.92 [1.36-2.75] vs. an urban area), parents not following health recommendations or using alternative medicines (1.81 [1.41-2.34] and 1.23 [1.04-1.46], respectively, vs. parents confident in institutions and following heath recommendations), not being visited by a maternal and child protection service nurse during the child's first two months (1.19 [1.03-1.38] vs. ≥ 1 visit), and being followed by a general practitioner (2.87 [2.52-3.26] vs. a pediatrician). CONCLUSIONS: Incomplete vaccination was highly prevalent in the studied pediatric population and was associated with several socio-demographic, parental, and healthcare service characteristics. These findings may help in designing targeted corrective actions. WHAT IS KNOWN: • Incomplete vaccination in the pediatric population is a growing public health issue in high-income countries. • The partial understanding of the determinants of incomplete vaccination precludes the design of effective targeted corrective actions. WHAT IS NEW: • High prevalence of incomplete vaccination at age two years in France. • Incomplete vaccination was independently associated with several socio-demographic, parental, and healthcare service characteristics.

Longitudinal impact of psychosocial status on children's mental health in the context of COVID-19 pandemic restrictions.

Emerging research suggests that the prevalence of child and adolescent mental health problems has increased considerably during the COVID-19 crisis. However, there have been few longitudinal studies on children's mental health issues according to their social determinants in this context, especially in Europe. Our aim was to investigate the association between family socioeconomic status (SES) and children' mental health during the period of school closure due to COVID-19. Longitudinal data came from 4575 children aged 8-9 years old in 2020 and participating in the ELFE population-based birth cohort that focuses on children's health, development and socialization. Parents completed the Strengths and Difficulties Questionnaire (SDQ) when children were (a) 5 years of age and (b) 9 years of age, which corresponded to the period of school closure due to the COVID-19 pandemic in France. We retrieved data from the ELFE cohort collected on children from birth to age 5 years (birth, 1 year, 2 years, 3,5 years and 5 years). Socioeconomic status (SES) was measured based on information obtained when the child was 5 years old. Data were analyzed using multinomial logistic regression models. Children's elevated levels of symptoms of Attention-deficit/Hyperactivity disorder (ADHD) during the period of school closure were significantly associated with prior low family SES (aOR 1.26, 95% CI 1.08-1.48). Children's elevated symptoms of hyperactivity/inattention and of emotional symptoms were associated with decline in income during the COVID crisis (respectively, aOR 1.38, 95% CI 1.16-1.63 and aOR 1.23, 95% CI 1.01-1.51). Moreover, when testing interactions, a low prior SES was significantly associated with a higher risk of emotional symptoms aOR 1.54 (1.07-2.21), only for children whose families experienced a decline in income, while gender, parental separation and prior mental health difficulties were not associated. This study underlines the impact of the financial crisis related to the COVID-19 epidemic on children's mental health. Both pre-existing family SES before lockdown and more proximal financial difficulties during the COVID crisis were negatively associated with children's psychological difficulties during the period of school closure. The pandemic appears to exacerbate mental health problems in deprived children whose families suffer from financial difficulties.

Sociodemographic and behavioural factors of adherence to the no-screen guideline for toddlers among parents from the French nationwide Elfe birth cohort.

BACKGROUND: Excessive screen time in infancy and childhood has been associated with consequences on children's development and health. International guidelines call for no screen time before age 2 years, whereas in France, the most prominent guidelines recommend no screen before age 3 years. However, data are lacking on parental adherence to the no-screen guideline for toddlers and factors of adherence in France. Using data from the French nationwide Elfe birth cohort, we estimated adherence to the no-screen guideline at age 2 years and examined related factors, including sociodemographic characteristics, parental leisure activities and screen time. METHODS: In 2011, 18,329 newborns and their parents were enrolled in 349 randomly selected maternity units across mainland France. At age 2 years, screen exposure of 13,117 toddlers was reported by parents in phone interviews. Data on sociodemographic characteristics, parental leisure activities and screen time were collected from both parents. Three patterns of parental leisure activities were derived by principal component analysis: literate (e.g.,reading), screen-based, and physical/artistic activities. Multivariable logistic regression models were used to examine the associations of sociodemographic characteristics, parental leisure activities and parental screen time with adherence to the no-screen guideline for toddlers. RESULTS: Overall, 1809/13,117 (13.5%) families adhered to the no-screen guideline for toddlers. Adherence was reduced with maternal age < 40 years, low parental education, single-parent household and parental migration status. After adjusting for sociodemographic characteristics, adherence to the guideline was positively associated with a parental literate activity pattern (mothers: odds ratio [95% confidence interval]: 1.15 [1.08, 1.22]); fathers: 1.15 [1.07, 1.23]) and negatively with a screen-based activity pattern (mothers: 0.73 [0.69, 0.77]; fathers: 0.81 [0.76, 0.87]). With each additional hour of parental screen time, mothers and fathers were less likely to adhere to the guideline (mothers: adjusted odds ratio 0.80 [0.77, 0.83]; fathers: 0.88 [0.85, 0.91]). CONCLUSIONS: Adherence to the no-screen guideline for toddlers in France was low. Parental leisure activities and parental screen time are major factors of adherence to the no-screen guideline and could be considered in targeted public health interventions.

The external validation of the asthma prediction tool in the French ELFE cohort.

BACKGROUND: Existing predictive scores for early identification of children at high risk of developing asthma include invasive procedures, and hence have limited utility in a primary care setting. The Leicestershire respiratory cohort (LRC) has developed a noninvasive asthma prediction tool (APT) for children with promising results. We aimed to perform its external validation in the French general population Étude Longitudinale Française depuis l'Enfance (ELFE) cohort. METHODS: Predictive scores were determined at Age 1 and the primary outcome of asthma was defined as parental reporting of "asthma ever or "wheezing in the past 12 months" at Age 5. Logistic regression was used to calculate the odds ratio (OR) and performance measures, and discriminative performance was reported using the receiver operating curve and area under curve (AUC). Calibration was assessed using Hosmer-Lemeshow goodness-of-fit test and visualized with a calibration plot. Overall performance was determined using Brier scores. RESULTS: Of the 10,689 children analyzed: 84.9% were at low, 13.1% medium, and 2% at high risk of developing asthma at Age 5. Children in the medium-risk category were three times more likely to develop asthma (OR = 3.3, 95% confidence interval [CI] = 2.97-3.78) whereas 13 times more likely in the high-risk category (OR = 13.8, 95% CI = 10.2-18.8). The tool's AUC was comparable: LRC 0.74 versus ELFE 0.68; as were the Brier scores LRC 0.16 versus ELFE 0.14. The tool's performance was robust to changes in inclusion criteria and outcome definitions. CONCLUSIONS AND RELEVANCE: Results of the present study and previous validation studies performed in high-risk populations provide a comprehensive measure of the effectiveness of the APT, providing encouragement for its application by general practitioners.

Enrichment of Formula in Probiotics or Prebiotics and Risk of Infection and Allergic Diseases up to Age 5.5 Years in the Nationwide Etude Longitudinale Française depuis l'Enfance (ELFE) Cohort.

BACKGROUND: An increasing number of infant and follow-on formulas are enriched with probiotics and/or prebiotics; however, evidence for health effects of such enrichment in early childhood remains inconclusive. OBJECTIVES: The present study aimed to assess whether the consumption of formula enriched with probiotics or prebiotics was associated with the risk of infection and allergic diseases in early childhood. METHODS: Analyses involved data for 8389 formula-fed children from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort. Enrichment of the formula with probiotics or prebiotics that was consumed from the age of 2-10 mo was identified by the formula ingredient list. Lower respiratory tract infection (LRTI), upper respiratory tract infection (URTI), gastrointestinal infection, wheezing, asthma, food allergy, and itchy rash were prospectively reported by parents up to the age of 5.5 y. Adjusted logistic regression models were used to assess associations between the consumption of enriched formula and risk of infection and allergic diseases. RESULTS: Aged 2 mo, more than half of formula-fed infants consumed the probiotic-enriched formula and only 1 in 10 consumed the prebiotic-enriched formula. Consumption of the Bifidobacterium lactis-enriched formula at 2 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.84 (0.73-0.96)]. Consumption of the Bifidobacterium breve-enriched formula up to 6 mo was associated with a higher risk of LRTI [OR (95% CI) = 1.75 (1.29-2.38)] and asthma [OR (95% CI) = 1.95 (1.28-2.97)], whereas its consumption from 6 to 10 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.64 (0.48-0.86)] and asthma [OR (95% CI) = 0.59 (0.40-0.88)]. Moreover, the consumption of Streptococcus thermophilus from 6 to 10 mo was associated with a higher risk of asthma [OR (95% CI) = 1.84 (1.29-2.63)]. No significant association was found for gastrointestinal infection, food allergy, and itchy rash. Overall, the consumption of prebiotic-enriched formula was not significantly associated with infection and allergy risk. CONCLUSIONS: Associations between the consumption of probiotic-enriched formula and risk of respiratory symptoms differ according to the strain considered and consumption period. Further well-designed studies are needed to confirm these results.

Testing the assumptions of customized intrauterine growth charts using national birth studies.

INTRODUCTION: Customized intrauterine growth charts are widely used for growth monitoring and research. They are based on three assumptions: (1) estimated fetal weight (EFW) has a normal distribution with a constant coefficient of variation at all gestational ages; (2) Hadlock's growth curve accurately describes the relation between EFW and gestational ages; (3) associations between EFW and the fetal and maternal characteristics included in the customization model (fetal sex, pre-pregnancy weight, height, parity) are proportional throughout pregnancy. The aim of this study was to test whether these underlying assumptions are verified. MATERIAL AND METHODS: Data came from (1) the French Longitudinal Study of Children (ELFE) cohort, which recruited births after 32 weeks' gestation in 349 maternity hospitals in France in 2011, and (2) the National Perinatal Survey, which included births from all French maternity hospitals in 2016. The study population included, respectively, 6 920 and 8 969 singleton non-malformed term live births with data on customization characteristics and EFW. We computed the coefficient of variation by gestational age and then modeled the association of gestational age, maternal and fetal characteristics with EFW at the second and third trimester ultrasound and with birthweight using linear regression. To assess the proportionality of the impact of maternal and fetal characteristics, we computed the percent change in weight associated with these characteristics at these three time points. RESULTS: The coefficient of variation was close to 12% at each gestational age, but EFW was not normally distributed, leading to small but systematic underestimation of fetuses under the 10th percentile. Weights representing the 50th and 10th percentiles based on Hadlock's growth trajectory were lower than observed or predicted weights. Most characteristics more strongly impacted weight at birth than during pregnancy. In the French Longitudinal study of Children (ELFE) cohort, boys were 1.8% (95% confidence interval [CI] 1.3-2.4) heavier than girls in the third trimester, whereas this percentage was 4.6% (95% CI 4.0-5.2) at birth. In the National Perinatal Survey, these percentages were 2.3% (95% CI 1.8-2.8) and 4.3% (95% CI 3.8-4.8). CONCLUSIONS: These results from two independent sources revealed discrepancies between routine clinical EFW data used for growth monitoring and the customized growth model's assumptions.

Enrichment of Formula in Probiotics or Prebiotics and Risk of Infection and Allergic Diseases up to Age 5.5 Years in the Nationwide Etude Longitudinale Française depuis l'Enfance (ELFE) Cohort.

BACKGROUND: An increasing number of infant and follow-on formulas are enriched with probiotics and/or prebiotics; however, evidence for health effects of such enrichment in early childhood remains inconclusive. OBJECTIVES: The present study aimed to assess whether the consumption of formula enriched with probiotics or prebiotics was associated with the risk of infection and allergic diseases in early childhood. METHODS: Analyses involved data for 8389 formula-fed children from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort. Enrichment of the formula with probiotics or prebiotics that was consumed from the age of 2-10 mo was identified by the formula ingredient list. Lower respiratory tract infection (LRTI), upper respiratory tract infection (URTI), gastrointestinal infection, wheezing, asthma, food allergy, and itchy rash were prospectively reported by parents up to the age of 5.5 y. Adjusted logistic regression models were used to assess associations between the consumption of enriched formula and risk of infection and allergic diseases. RESULTS: Aged 2 mo, more than half of formula-fed infants consumed the probiotic-enriched formula and only 1 in 10 consumed the prebiotic-enriched formula. Consumption of the Bifidobacterium lactis-enriched formula at 2 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.84 (0.73-0.96)]. Consumption of the Bifidobacterium breve-enriched formula up to 6 mo was associated with a higher risk of LRTI [OR (95% CI) = 1.75 (1.29-2.38)] and asthma [OR (95% CI) = 1.95 (1.28-2.97)], whereas its consumption from 6 to 10 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.64 (0.48-0.86)] and asthma [OR (95% CI) = 0.59 (0.40-0.88)]. Moreover, the consumption of Streptococcus thermophilus from 6 to 10 mo was associated with a higher risk of asthma [OR (95% CI) = 1.84 (1.29-2.63)]. No significant association was found for gastrointestinal infection, food allergy, and itchy rash. Overall, the consumption of prebiotic-enriched formula was not significantly associated with infection and allergy risk. CONCLUSIONS: Associations between the consumption of probiotic-enriched formula and risk of respiratory symptoms differ according to the strain considered and consumption period. Further well-designed studies are needed to confirm these results.

Early postnatal growth and subsequent neurodevelopment in children delivered at term: The ELFE cohort study.

BACKGROUND: Despite the limited evidence, accelerated early postnatal growth (EPG) is commonly believed to benefit neurodevelopment for term-born infants, especially those small for gestational age. OBJECTIVES: To investigate the existence of critical time windows in the association of EPG with neurodevelopment, considering birth size groups. STUDY DESIGN: In the French ELFE birth cohort, 12,854 term-born neonates were classified as small, appropriate or large for gestational age (SGA, AGA, LGA, respectively). Parents reported their child's development by using the Child Development Inventory (CDI-score) at age 12 months and the MacArthur-Bates Development Inventory (MAB-score; 100 score units) assessing language ability at age 24 months. Predictions of individual weight, body mass index (BMI), length, and head circumference (HC) from birth to age 24 months were obtained from repeated measurements fitted with the Jenss-Bayley mixed-effects model. For each infant, conditional gains (CG) in these growth parameters were generated at four-time points (3, 6, 12 and 24 months) representing specific variations in growth parameters during 0-3, 3-6, 6-12, 12-24 months, independent of previous measures. Using multivariable linear regression models, we provided the estimate differences of the neurodevelopmental scores according to variation of each growth parameter CG, by birth size group. RESULTS: For SGA infants, the MAB-score differed by 5.8 (95% confidence interval [CI] -0.2, 11.8), 6.7 (95% CI -0.1, 13.3), and 9.7 (95% CI 1.9, 17.5) score units when CG in BMI, weight, and HC at 3 months varied from -2 to 1 standard deviation, respectively. For all infants, MAB-score was linearly and positively associated with length conditional gains at 12 months, with stronger magnitude for SGA infants. Results for the CDI-score were overall consistent with those for MAB-score. CONCLUSIONS: For term-born SGA infants, moderate catch-up in HC, BMI and weight within the first 3 months of life may benefit later neurodevelopment, which could guide clinicians to monitor EPG.