Aims: To determine whether sleeping position in the first 6 months is associated with long-term phenotypic changes.

Hypotheses:

1. That there is no adverse association of long-term physical health associated with sleeping on the back or side.

2. That a consequence of increased risk of chest infection associated with prone sleep position is a reduction in lung function in childhood.

3. That prone sleeping may be associated with improved motor ability and coordination.

4. That sleeping position has no long-term effect on cognitive abilities, behaviour or educational attainment.

Exposure variables:

Sleeping position, and other features of bedding and parenting up to 18 months

Outcome variables

All phenotypes on the database

Confounding variables

Gender; socio-economic features; housing; diet; parental education; child care; birthweight; gestation; etc.

Statistical approach will use a phenome scan, taking account of multiple testing. Regression analyses will be used to account for confounders as appropriate.