In many families the issue of where a baby sleeps is never questioned. Cultural rules or assumptions specify 'the normal place' for infant sleep within a given society -- whether that be a cot or crib in a specially prepared nursery, a futon on the floor along-side the mother, or strapped to the mother's body in a sling.
In Western 21st century, where environments for infant sleep may vary from household to household, recommendations for where babies sleep are made on the basis of enhancing infant safety. Reducing the number of sudden and unexpected infant deaths during sleep (from accidents or unknown causes) is the principal reason why guidance on 'where babies sleep' is issued by Health Departments and other organisations.
To identify the safest options epidemiological studies (case-control studies) are undertaken to ascertain the key differences between babies who have previously died versus matched control groups of babies who haven't died. The resulting statistics (odds ratios) that are produced indicate which elements of the sleep environment, the infant, the parents, or the larger social context may be contributing to an increased risk of infant death. These are the potential 'risk factors' that might prevent infant deaths if avoided, and several of them involve where babies sleep.
Infant safety is not the only issue that might affect where babies sleep, however, and parents regularly make trade-offs between safety and other issues - sometimes on the basis of informed decisions, and sometimes due to unanticipated circumstances (Volpe & Ball 2014).
Health professionals who are aware of the pros and cons of various infant sleep locations, and the basis for the risk-reduction recommendations, are equipped to provide families with the specific information they might need.
It is important to recognise that despite antenatal professional recommendations and parental intentions, what happens once the baby arrives can be very different and often outweighed by convenience for mother and baby, breastfeeding and sleep quality once parental exhaustion becomes a reality (Rudzik and Ball 2016, Stremmler 2013).