ABCD

    Characteristic

    Description

     

           Name of the cohort 
     

    Amsterdam Born Children and their Development (ABCD study)

     

           Description / aim of the cohort 

    The ABCD study is a prospective birth cohort that examines the health of children from pregnancy until adulthood. It aims to inventarise and analyze the relationship between maternal lifestyle, medical, psychosocial, and environmental conditions during pregnancy and early life, and children's health at birth and in later life. A specific focus lies on analyzing sociodemographic disparities in these health outcomes to identify factors that explain future health differences.

     

           Description of the cohort population (age, specific characteristics, e.g. adults with cardiovascular disease, low SEP) 

              Start Population (Pregnancy): 12,373 pregnant women approached in Amsterdam (2003-2004).

     

              Participants: 8,266 women filled out the pregnancy questionnaire.

     

              Ethnicity (maternal country of birth): Multi-ethnic cohort including Dutch (58%), Surinamese (6.5%), Turkish (4.6%), Moroccan (8.5%), other non-Western (13.1%), other Western backgrounds (6.8%) and unknown (2.5%).

     

              Current Status: Children are currently young adults (approx. 20+ years old).

     

           Location of the cohort

    Amsterdam

     

           Institution

    Amsterdam UMC Department of Public and Occupational Health

           Cohort size (n)

              Baseline: 8,266 pregnancies included.

              Live births followed: 7,863 singletons.

              Current Retention: Varies per phase (see follow-up below).

     

           Start year of the cohort

    2003 (Recruitment: Jan 2003 March 2004)

     

           Follow-up (years and n)

              Phase 1 (Pregnancy): 2003 2004 (n=8,266 women)

              Phase 2 (Infancy): 2003 2005 (Age 3 months, n=5,218)

              Phase 3 (Early Childhood): 2008 2010 (Age 5-6 years, n=4,488)

              Phase 4 (Pre-teens): 2015 2016 (Age 11-12 years, n=3,018 children, n=3,230 Youth Healthcare registry linkage)

              ELSO Sub-study: 2018 (Age 14, n=112)

              Phase 5 (Adolescence): 2019 2020 (Age 15-16 years, n=2,189 mothers)

              Phase 6 (Young Adulthood): 2022 (Age 17-18 years, n=1,678)

              Phase 7 (Adulthood): 2023 2025 (Age 19-20 years, ongoing)

     

           Types of variables (e.g., health behaviours, psychosocial factors, clinical health outcomes, demographic characteristics)

           Measurement methods (e.g., questionnaires, clinical assessments, biosamples)

    Types of variables, measurement methods, and variable categories:

    (summarised, non-exhaustive, and structured by domain)

     

    Phase 1: Pregnancy

              Maternal Health: Obstetric history, medication (ATC), complications, BMI, blood pressure.

              Lifestyle: Smoking, alcohol, drugs, folic acid use, nutrition (fish consumption).

              Psychosocial: Work stress (Job Content Questionnaire), anxiety (PRAQ/STAI), depression (CES-D), fatigue (MFI).

              Biological: Blood biomarkers (Lipids, fatty acids/PUFAs, micronutrients, cortisol).

     

    Phase 2: Infancy (3 months)

              Nutrition: Breastfeeding vs. formula (duration), introduction of solids.

              Health: Growth curves (via Youth Health Care), crying behavior, sleep patterns, infant ailments.

              Parenting: Burden of care, maternal fatigue (MFI), depression (CES-D).

     

    Phase 3: Early Childhood (5-6 years)

              Physical Health: Anthropometry (height, weight, waist), blood pressure, heart rate (VIG/PEP).

              Nutrition: Eating behavior (CEBQ), dietary intake/sugar (Food Frequency Questionnaire).

              Development: School performance (CITO), psychosocial problems (SDQ, Teacher report).

              Biological: Metabolic blood profile (lipids, glucose) & Genetics (GWAS).

     

    Phase 3b/3c: School Age (7-8 years)

              Specific: Asthma/Allergies (ISAAC), Sleep habits (CSHQ), Screen time, EMF exposure (bedroom measurements).

     

    Phase 4: Pre-teens (11-12 years)

              Clinical Linkage (JGZ): Dental health, vision, hearing, vaccination status.

              Psychosocial: Well-being, bullying, risk profile (SURPS), autism traits.

              Puberty: Physical maturation (Puberty Development Scale).

              Cognition: Computerized tasks (RAVEN intelligence, memory, risk-taking).

     

    ELSO Sub-study (14 years)

              Biological: Saliva samples (Cortisol awakening response), MRI brain scans, stress reactivity tasks.

     

    Phase 5: Adolescence (15-16 years)

              Risk Behavior: Alcohol, smoking, drugs, gambling, social media use.

              Mental Health: Depression/Anxiety (DASS-21), self-efficacy, sleep quality.

              Family: Parenting styles, family functioning.

     

    Phase 6: Young Adulthood (17-18 years)

              Well-being: Life events, coping skills, loneliness, impact of COVID-19.

              Passive Data: Smartphone usage (screen time apps), step count.

     

    Phase 7: Adulthood (19-20 years)

              Physical: Repeat anthropometry, cardiovascular function, sleep tracking (actigraphy).

     

    Measurement methods:

              Questionnaires: Self-reported by Mother, Father, Child, and Teacher (web-based/paper).

              Physical Health Checks: Clinical measurements at research locations/schools (blood pressure, anthropometry, body composition).

              Registry Linkage: Dutch Perinatal Registration (PRN) and Youth Health Care records (JGZ Amsterdam).

              Biosamples: Blood samples (DNA, Plasma, Serum) and Saliva samples (Cortisol).

              Passive Monitoring: Actigraphy (sleep/movement) and smartphone data logging.

     

    For a complete overview of available variables, see overview variables ABCD study phase 1-6:

    https://abcd.amsterdamumc.nl/wp-content/uploads/2025/12/Overview-variables-ABCD-study-phase-1-6-2025_website-version.pdf

     

           Oral health variables (questionnaire/self-reported)

    Phase 3 (Age 5-6): Detailed sugar and dietary intake via "Food Frequency Questionnaire" (FFQ) and "Child Eating Behaviour Questionnaire" (CEBQ).

     

    Phase 4 (Age 11-12): "Nutritional habits" and "Eating behavior" reported by child and parents.

     

    JGZ Linkage (approx. age 13, year 2017, N ~ 1392):

    1.       Dental check-up frequency: How often do you visit the dentist or dental hygienist for a check-up per year?

    2.       Toothbrushing frequency: How often do you brush your teeth per day?

    3.       Dental visits (categorized): 2 categories (≥ 1 time per year vs. < 1 time per year).

    4.       Toothbrushing (categorized): 2 categories (≥ 2 times per day vs. < 2 times per day).

    5.       Dental Risk Group: Categorized as Green, Orange, or Red.

     

           Oral health variables (clinically assessed)

    NA

           Oral health variables (biological, e.g., microbiome data, saliva)

    NA

           Reference to design paper

    Cohort profile:

    van Eijsden et al., 2011

     

           Website

    https://abcd.amsterdamumc.nl/

     

           Procedure for requesting data

    https://abcd.amsterdamumc.nl/gebruik-onze-data/

     

           Procedure for data storage

    Data exchange and storage locations are strictly defined in a Data Transfer Agreement (DTA).

     

    See ABCD collaboration policy:

    http://abcd.amsterdamumc.nl/wp-content/uploads/2025/08/ABCD-Collaboration-Policy-2025.pdf

     

           Associated costs for data requests (yes/no)

    Yes

           Contact person / principal investigator

    Dr. Tanja Vrijkotte

    t.vrijkotte@amsterdamumc.nl