Mother-baby bedsharing is associated with an increased risk of unexpected infant death, particularly for mothers who smoke or drink alcohol, but little is known of the potential beneficial effects of bedsharing (e.g. establishment or maintenance of breastfeeding), and recent US data has confirmed the beneficial effects of breastfeeding in reducing infant mortality. The Avon Longitudinal Study of Parents And Children (ALSPAC) has collected information on health, growth, development, medical, environmental and social factors from pregnancy to the present, in a cohort of 14,000 children born in 1991-2 and their families. Detailed information has been collected on sleep patterns, duration and place for the infants and their parents. Preliminary analysis of the data on sleep in infancy and childhood has shown that in the first 6 months 33-70% infants share a bedroom with their mother, and routine mother-baby bedsharing for night time sleep is common throughout infancy and early childhood, varying between 9% and 18%. Many factors (e.g. birthweight, breastfeeding), are associated with sleep patterns and duration, and, whilst short sleep duration in early infancy is associated with obesity in later childhood, breastfeeding (which is associated with bedsharing) may reduce the risk of obesity.

We will use complex statistical modelling techniques to analyse the data from ALSPAC children and families, to identify factors contributing to parents choices about bedsharing in infancy, together with any immediate or long term adverse consequences or benefits of bedsharing, room sharing or separate sleeping, for both children and mothers. The large size and completeness of the data from the ALSPAC cohort will allow us to take account of multiple psychological, medical, social and environmental factors that may have influenced decisions about infant care practices, and may themselves have been associated with potential benefits or adverse consequences (e.g. breastfeeding, maternal smoking, socio-economic deprivation, pacifier use).