Direct behavioral observation and motility monitoring procedures provide re
liable data, and both are appropriate for sleep/wake state measurements sta
rting immediately after birth. Using these procedures, newborn rats, rabbit
s, and humans were found to have a greater amount of quiet sleep on the day
of birth rather than 24 hr Inter. Changes in active sleep and wake were in
consistent across the 2 days. The quiet sleep findings are contrary to the
developmental course which increases with age. The findings are interpreted
as a temporary adaptive response to the stress of the birth process. (C) 1
999 John Wiley & Sons, Inc.