title: Relationship between infant and mother circadian rest-activity rhythm pre- and postpartum, in comparison to an infant with free-running rhythm.
abstract: Some infants show a free-running rhythm in their rest-activity. We do not know why, nor do we know exactly what the entrainment factors are for the development of the normal 24-h rest-activity rhythm. Actigraphic recordings on 10 primiparae during late pregnancy and these mothers and their infants during the 2nd, 6th, and 12th wks after birth were made over 3-5 continuous days to investigate maternal and infant entrainment. One infant showed a free-running rest-activity circadian rhythm. In late pregnancy, the period in the autocorrelogram of the mother with the free-running infant was longer than the significant period of the mean autocorrelogram of the mothers with non-free-running infants. The finding of this study indicates the free-running rhythm of infant is not reset by maternal entrainment factors.
authors.affiliation: Integrated Neuroscience Research Team, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. nishihara-kk@igakuken.or.jp
authors.forename: Kyoko
authors.initials: K
authors.lastname: Nishihara
authors.forename: Shigeko
authors.initials: S
authors.lastname: Horiuchi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Eto
authors.forename: Sawa
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hoshi
mesh_terms: D056044:Actigraphy; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology* / Q000523:psychology*; D007231:Infant, Newborn; D008297:Male; D008425:Maternal Behavior / Q000502:physiology* / Q000523:psychology*; D009043:Motor Activity / Q000502:physiology; D011247:Pregnancy; D012890:Sleep / Q000502:physiology*