RT Journal Article SR Electronic T1 Is parent–child bed-sharing a risk for wheezing and asthma in early childhood? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 661 OP 669 DO 10.1183/09031936.00041714 VO 45 IS 3 A1 Maartje P.C.M. Luijk A1 Agnes M.M. Sonnenschein-van der Voort A1 Viara R. Mileva-Seitz A1 Pauline W. Jansen A1 Frank C. Verhulst A1 Albert Hofman A1 Vincent W.V. Jaddoe A1 Johan C. de Jongste A1 Marinus H. van IJzendoorn A1 Liesbeth Duijts A1 Henning Tiemeier YR 2015 UL http://erj.ersjournals.com/content/45/3/661.abstract 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