Infant sleep-wake behaviors at two weeks, three and six months

Although infant sleep-wake behavior presents several developmental changes during the
first six months, literature lacks on reference values and few studies have explored the
role of individual change and stability on infant sleep-wake behavior during the first six
months. This study aimed (1) to describe infant sleep-wake behaviors during the 24-h
period, day and night, at two weeks, three, and six months, (2) and to explore developmental
changes and the role of individual change and stability on infant sleep-wake behaviors
from two weeks to six months. Ninety-four primiparous mothers completed measures on
infant sleep-wake behaviors at two weeks, three and six months. Significant developmental
changes were found on infant sleep-wake behaviors from two weeks to six months. Twoweek-
old infants sleep 13.3 h, spend 8.7 h awake, awake 6.1 times, have 0.4 h of latency to
sleep, and 3.2 h of longest sleep period. Three-month-old infants sleep 13.0 h, spend 9.2 h
awake, awake 5.5 times, have 0.4 h of latency to sleep, and 5.2 h of longest sleep period. Sixmonth-
old infants sleep 12.2 h, spend 10.0 h awake, awake 5.2 times, have 0.4 h of latency to
sleep, and 5.6 h of longest sleep period. Significant individual change and stability were also
found on infant sleep-wake behaviors from two weeks to six months. Despite significant
developmental and individual changes, individual stability explains a significant amount
of the variance on infant sleep-wake behaviors over the first six months of life.
FEDER Funds through the Programa Operacional Factores de Competitividade − COMPETE and by National Funds through FCT − Fundação para a Ciência e a Tecnologia under the project: PTDC/SAU/SAP/116738/2010 and SFRH/BSAB/14445/2014 grant
Portuguese Foundation for Science and Technology and the Portuguese Ministry of Education and Science through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145- FEDER-007653)
Psychology Research Centre (UID/PSI/01662/2013), University of Minho