PT - JOURNAL ARTICLE AU - Maartje P.C.M. Luijk AU - Agnes M.M. Sonnenschein-van der Voort AU - Viara R. Mileva-Seitz AU - Pauline W. Jansen AU - Frank C. Verhulst AU - Albert Hofman AU - Vincent W.V. Jaddoe AU - Johan C. de Jongste AU - Marinus H. van IJzendoorn AU - Liesbeth Duijts AU - Henning Tiemeier TI - Is parent–child bed-sharing a risk for wheezing and asthma in early childhood? AID - 10.1183/09031936.00041714 DP - 2014 Jan 01 TA - European Respiratory Journal PG - erj00417-2014 4099 - http://erj.ersjournals.com/content/early/2014/12/16/09031936.00041714.short 4100 - http://erj.ersjournals.com/content/early/2014/12/16/09031936.00041714.full AB - Household crowding can place young children at risk for respiratory infections which subsequently provoke asthma symptoms. However, crowding might also protect against asthma, in accordance with the hygiene hypothesis. We tested if parent–infant bed-sharing, an important dimension of household crowding, increases or decreases the risk for asthma. In a population-based prospective cohort (N = 6160) we assessed bed-sharing at 2 and 24 months; wheezing between 1 and 6 years of age; and asthma at 6 years of age. Generalised estimating equation models were used to assess repeated measures of wheezing and asthma. We found no association between bed-sharing in early infancy and wheezing or diagnosis of asthma. By contrast, we found a positive association between bed-sharing in toddlerhood and both wheezing (OR 1.42, 95% CI 1.15–1.74) and asthma (OR 1.57, 95% CI 1.03–2.38). Wheezing was not associated with bed-sharing when using cross-lagged modelling. This study suggests that bed-sharing in toddlerhood is associated with an increased risk of asthma at later ages, and not vice versa. Further studies are needed to explore the underlying causal mechanisms. More wheezing and asthma reported for bed-sharing toddlers, not for infants: parental vigilance or increased risk? http://ow.ly/Dgy4v