Dear Georgeanne, I couldn't ignore a request from someone from upstate
PA--my mother was from Mahanoy City and my cousins live in Zion Grove!

It's EASY to find medical literature on the internet now that there's
"PubMed" -- type that in and you'll get access to a free version of
Medline that is even better than the original Medline!

Here's what I found (citations with abstracts of 4 articles):
************************************************************************
Acta Paediatr Suppl 397: 94-102 (Jun 1994)
Sleep and arousal, synchrony and independence, among mothers and infants
sleeping apart and together (same bed): an experiment in evolutionary
medicine.
McKenna JJ, Mosko SS
Abstract:
"Although solitary sleeping in infancy is a very recent custom, limited to
Western industrialized societies, and most contemporary people practice
parent-infant co-sleeping, virtually all laboratory research on sleep in
human infants assumes that solitary infant sleep is the normal and
desirable environment. We have used evolutionary and developmental data to
challenge this view. We suggest that co-sleeping provides a sensory-rich
environment which is the more appropriate environment in which to study
infant sleep. In addition, two preliminary, in-laboratory, polygraphic
investigations of mother-infant co-sleeping are reported in normal
infants, within the peak age range for sudden infant death syndrome
(SIDS). Five mother-infant pairs co-slept one night in the first study; in
the second, three additional pairs slept separately for two nights and
co-slept the third consecutive night. The results suggest that co-sleeping
is associated with enhanced infant arousals and striking temporal overlap
(synchronicity) in infant and maternal arousals, and that, possibly as a
result, co-sleeping mothers and infants spend more time in the same sleep
stage or awake condition. The implications of the hypothesis and
preliminary results for research on the normal development of infant sleep
and on SIDS are discussed."

Sleep 16 (3): 263-282 (Apr 1993)
Infant-parent co-sleeping in an evolutionary perspective: implications for
understanding infant sleep development and the sudden infant death
syndrome.
McKenna JJ, Thoman EB, Anders TF, Sadeh A, Schechtman VL, Glotzbach SF
Abstract:
"Evidence suggests that infant-parent co-sleeping represents the
species-wide pattern of sleep in which human infant physiology evolved.
The hypothesis evaluated in this manuscript is that the co-sleeping
environment may foster development of optimal sleep patterning in infants
and confer other benefits, including reducing the risk of the sudden
infant death syndrome (SIDS). These postulations by McKenna are considered
from different perspectives by the coauthors. Using evolutionary,
cross-species, crosscultural, physiological and behavioral data, our
objective was to present a conceptual framework for assessing the
developmental consequences of solitary sleeping and infant-parent
co-sleeping."


Am J Phys Anthropol 83 (3): 331-347 (Nov 1990)
Sleep and arousal patterns of co-sleeping human mother/infant pairs: a
preliminary physiological study with implications for the study of sudden
infant death syndrome (SIDS).
McKenna JJ, Mosko S, Dungy C, McAninch J
Abstract:
"The prevailing research design for studying infant sleep erroneously
assumes the species-wide normalcy of solitary nocturnal sleep rather than
a social sleeping environment. In fact, current clinical perspectives on
infant sleep, which are based exclusively on studies of solitary sleeping
infants, may partly reflect culturally induced rather than species-typical
infant sleep patterns which can only be gleaned, we contend here, from
infants sleeping with their parents--the context within which, and for
well over 4 million years, the hominid infant's sleep, breathing, and
arousal patterns evolved. Our physiological study of five co-sleeping
mother-infant pairs in a sleep lab is the first study of its kind to
document the unfolding sleep patterns of mothers and infants sleeping in
physical contact. Our data show that co-sleeping mothers and infants
exhibit synchronous arousals, which, because of the suspected relationship
between arousal and breathing stability in infants, have important
implications for how we study environmental factors possibly related to
some forms of the sudden infant death syndrome (SIDS). While our data show
that co-sleeping mothers and infants also experience many moments of
physiological independence from each other, it is clear that the temporal
unfolding of particular sleep stages and awake periods of the mother and
infant become entwined and that on a minute-to-minute basis, throughout
the night, much sensory communication is occurring between them. Our
research acknowledges the human infant's evolutionary past and considers
the implications that nocturnal separation (a historically novel and alien
experience for them) has for maternal and infant well-being in general and
SIDS research strategies in particular."


Early Hum Dev 38 (3): 187-201 (Sep 15 1994)
Experimental studies of infant-parent co-sleeping: mutual physiological
and behavioral influences and their relevance to SIDS (sudden infant death
syndrome).
McKenna J, Mosko S, Richard C, Drummond S, Hunt L, Cetel MB, Arpaia J
Abstract:
"We hypothesize that maternal sensory exchanges, likely involving a
combination of heat, sound, gas, smells, movement, and touch, induce
important physiological changes, especially in the healthy infant's
arousal patterns, body temperature, and sleep architecture as defined by
standard physiological measures. We summarize the results of two
preliminary physiological studies, and some early data from a third, in
which mothers and infants are monitored using standard polysomnographic
techniques as they sleep in the same bed, and then in adjacent rooms. Our
data suggest that infant-parent co-sleeping alters the infant's sleep
experience as, for example, the characteristics of arousals, the frequency
and duration of nursing, infant sleep position and the number of maternal
inspections. For example, while sleeping in the same bed, mothers nurse
their infants three times more frequently than they do while their infants
sleep in an adjacent room. These preliminary data demonstrate significant
differences between routine co-sleeping and solitary sleeping
environments. This work underscores the importance of studying infant
sleep as it unfolds in the co-sleeping environment, the environment within
which it evolved over at least 5 million years of human evolution. Should
our preliminary findings be confirmed in future studies they will provide
a beginning point for considering additional, possibly unconventional ways
of helping to reduce SIDS risks."
**************************************************************************
Ginna Wall, MN, IBCLC, Lactation Services Coordinator
University of Washington Medical Center, Mailbox 356153
1959 NE Pacific Street, Seattle WA 98195
Voicemail: (206)548-6368, Fax: (206)548-7665