'Is s/he a good baby?' is a question commonly posed to new mothers and fathers in the early days of parenthood. Typically the enquirer wants to know whether the baby is 'contented' and 'sleeps well'. Those whose babies are 'good' are congratulated. Those whose babies are 'troublesome' receive sympathy and tips on how to improve their baby's sleep habits.
The 'good' baby
A 'good' or 'contented' baby in Western society, it seems, is a comatose baby, and the management of infant sleep is one of the first areas of parenting by which new mothers and fathers are judged by others. It is not surprising then that infant sleep issues are a source of anxiety and frustration for many parents.
Sleep patterns change over time
Sleep is a developmental process, and our sleep needs change throughout our lifetimes. Babies' sleep patterns mature over the first several years of life, and the sleep architecture of newborns is very different to that of adults. Newborns sleep for 18-20 or so hours a day, but only for 2-3 hours at a time. During the first year overall sleep duration falls to around 15 hours, and the majority of sleep becomes consolidated during night-time as circadian rhythms develop (Parmelee et al 1964).
What is 'normal' infant sleep?
However, both paediatric and popular knowledge about babies' sleep maturation and regulation is primarily based upon studies of formula-fed infants sleeping alone. In the following pages we review the research evidence about normal infant sleep, and wherever possible we consider the sleep of babies who are fed human milk to be the 'biologically normal' condition.