Early daycare is associated with an increase in airway symptoms in early childhood but is no protection against asthma or atopy at 8 years

Am J Respir Crit Care Med. 2009 Sep 15;180(6):491-8. doi: 10.1164/rccm.200903-0327OC. Epub 2009 Jun 19.


Rationale: Daycare exposes young children to more infections early in life and may thereby prevent the development of asthma and allergy.

Objectives: To prospectively study the effect of daycare on the development of asthma and allergic sensitization during the first 8 years of life.

Methods: In the Prevention and Incidence of Asthma and Mite Allergy birth cohort 3,963 newborn children were followed prospectively for 8 years. Daycare use and respiratory health were assessed yearly by questionnaires. At 8 years, sensitization to airborne allergens and airway responsiveness were measured. Daycare was defined as early (aged 0-2 yr), late (aged 2-4 yr), or none (no daycare before age 4 yr). Associations of daycare and/or older siblings with asthma symptoms (wheezing, shortness of breath, and inhaled steroids taken in the last year), airway responsiveness, and allergic sensitization were assessed in a longitudinal repeated-event analysis.

Measurements and main results: Children with early daycare had more wheezing in the first years of life, but less wheezing and steroid use between 4 and 8 years of age. At the age of 8 years, early daycare was not protective for asthma symptoms (adjusted odds ratio [aOR], 0.99; 95% confidence interval [CI], 0.74-1.32), allergic sensitization (aOR 0.86; 95% CI, 0.63-1.18), or airway hyperresponsiveness (aOR, 0.80; 95% CI, 0.57-1.14). The transient reduction in airway symptoms between age 4 and 8 years was only observed in children without older siblings.

Conclusion: Early daycare is associated with an increase in airway symptoms until the age of 4 years, and fewer symptoms between the ages of 4 and 8 years. We found no protection against asthma symptoms, hyperresponsiveness, or allergic sensitization at the age of 8 years.

MeSH terms

  • Administration, Inhalation
  • Age Factors
  • Allergens / immunology
  • Antigens, Dermatophagoides / immunology*
  • Asthma / epidemiology
  • Asthma / immunology*
  • Asthma / prevention & control
  • Bronchial Hyperreactivity / immunology
  • Child
  • Child Day Care Centers*
  • Child, Preschool
  • Environmental Exposure
  • Female
  • Humans
  • Hypersensitivity / epidemiology
  • Hypersensitivity / immunology*
  • Hypersensitivity / prevention & control
  • Immunoglobulin E / blood
  • Infant
  • Infant, Newborn
  • Male
  • Netherlands / epidemiology
  • Prospective Studies
  • Respiratory Sounds / immunology
  • Respiratory Tract Infections / drug therapy
  • Respiratory Tract Infections / epidemiology
  • Respiratory Tract Infections / immunology
  • Siblings
  • Spirometry
  • Steroids / administration & dosage


  • Allergens
  • Antigens, Dermatophagoides
  • Steroids
  • Immunoglobulin E