Profiles of the maternal occupational exposome during pregnancy and associations with intrauterine growth: Analysis of the French Longitudinal Study of Children - ELFE study.

Background: Numerous agents in the workplace are suspected of impairing fetal growth. To date, no epidemiological studies have specifically described the occupational exposome during pregnancy.

Objective: The objectives were to determine maternal occupational exposome profiles and study their associations with intrauterine growth characteristics measured by small for gestational age (SGA), birthweight (BW), and head circumference (HC).

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.

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).

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.

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.

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.

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 , 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.

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.

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.

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.

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.

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.

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.

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.

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).

Neurodevelopmental outcomes at age 5 among children born preterm: EPIPAGE-2 cohort study.

Objectives: To describe neurodevelopment at age 5 among children born preterm.

Design: Population based cohort study, EPIPAGE-2.

Setting: France, 2011.

Diet during pregnancy: Influence of social characteristics and migration in the ELFE cohort.

Better adherence to dietary guidelines during pregnancy is supposed to result in healthier perinatal outcomes. We aim to characterize the diets of pregnant women by hypothesis-driven and exploratory approaches and describe potential social determinants. Analyses included 12 048 mothers from the French nationwide ELFE birth cohort.

Pregnancy outcomes in women with preexisting thyroid diseases: a French cohort study.

Women with thyroid diseases at the beginning of pregnancy may have suboptimal thyroid hormone levels because of potential difficulties in compensating for the physiological thyroid hormone changes occurring in pregnancy. Our objective was to study the association between preexisting thyroid diseases, pregnancy complications, and neonatal anthropometry. In total, 16,395 women from the ELFE French longitudinal birth cohort were included, and 273 declared pre-pregnancy thyroid diseases.