Apnea and sleep state in newborns and infants.

Many studies have shown a greater frequency of apneas in active sleep than in quiet sleep in healthy newborns and infants, both full-term and preterm. The ontogeny of increased apnea during active sleep is related to phasic inhibitory-excitatory central mechanisms occurring during active sleep. Respiratory instability in active sleep can be increased by factors which modify the newborn's or infant's homeostasis. We have shown: (1) an increase in body temperature (0.8 degrees C) significantly augments periodic breathing in preterm infants at 40 weeks postconceptional age; (2) maternal administration of meperidine is followed by a significant increase in number of apneas during the first hours of life in full-term newborns, but only during active sleep; (3) sleep deprivation induces significantly more obstructive respiratory events in active sleep than in quiet sleep in infants. Active sleep appears to be a risk period for exaggeration of the occurrence of apneas when the newborn's or infant's homeostasis is disturbed.