Oesophageal motor activity and sleep state in the newborn human infant.

Oesophageal pressure and ventilation were recorded during sleep in healthy full-term neonates with sleep state defined by one of two methods; in 35 infants by combined behavioural and electroencephalographic criteria, and in a further 13 infants by behavioural criteria alone. Spontaneous oesophageal contractions occurred in all infants during active sleep but rarely during quiet sleep. The transition from active to quiet sleep was accompanied by a gradual reduction in the frequency of these contractions. Oesophageal contractions associated with sighs and contractions shortly following interruption of breathing suggestive of swallowing were also significantly more common in active sleep. In 13 infants who showed periodic breathing the same differences in prevalence of spontaneous oesophageal contractions in each sleep state were observed.