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PHYSIOLOGICAL RESPONSES DURING SLEEP Chapter 2
The importance of mother-baby interactions in determining nighttime thermal conditions for sleeping infants: Observations from the home and the sleep laboratory Peter Fleming MB PhD FRCPC, Jeanine Young RN PhD, Peter Blair PhD
P Fleming, J Young, P Blair. The importance of mother-baby interactions in determining nighttime thermal conditions for sleeping infants: Observations from the home and the sleep laboratory. Paediatr Child Health 2006;11(Suppl A):7A-10A. Several studies have highlighted the potential importance of the thermal environment in the etiology of sudden infant death syndrome. In a case-control study, it was shown that having a mother who was worried about the possibility of her baby becoming too cold was a risk factor for sudden infant death syndrome. In a longitudinal study of normal, healthy infants sleeping in a metabolic chamber in a sleep laboratory, the optimal conditions for thermal neutrality were defined for sleeping infants from birth to three months, and the infants’ metabolic and peripheral vasomotor responses to cold stress were quantified for each sleep state at each age. In a subsequent study of infants sleeping at home, it was shown that mothers were able to accurately and consistently achieve conditions of predicted thermal neutrality for their infants during the night. In this study, infants who slept in slightly colder environmental conditions were more prone to respiratory infections during the first six months after birth. Further studies of infants and their mothers sleeping together in the sleep laboratory – either sharing the room or sharing the bed – identified complex interactions between mothers and babies that ensured effective thermoregulation despite higher environmental temperatures when mothers and babies shared a bed.
Key Words: Bed sharing; Cosleeping; Thermal neutrality; Thermal stress; Thermoregulation
Interactions mère-enfant et leurs répercussions sur les conditions thermiques du sommeil nocturne des nourrissons : Observations à domicile et en laboratoire du sommeil Plusieurs études ont souligné l’importance potentielle de l’environnement thermique dans l’étiologie du syndrome de mort subite du nourrisson (SMSN). Selon une étude cas-témoins, le fait qu’une mère s’inquiète de la possibilité que son bébé ait trop froid constitue un facteur de risque à l’égard du SMSN. Lors d’une étude longitudinale auprès de nourrissons normaux en bonne santé qui dormaient dans une chambre métabolique d’un laboratoire du sommeil, les conditions optimales de neutralité thermique ont été définies pour le sommeil des nourrissons de la naissance à l’âge de trois mois et les réactions métaboliques et vasomotrices périphériques des nourrissons au froid ont été quantifiées pour chacun des états de sommeil à chaque âge. Lors d’une étude subséquente sur le sommeil des nourrissons à domicile, il a été démontré que les mères étaient capables d’obtenir avec précision et constance les conditions de neutralité thermique prévues pour leur nourrisson durant la nuit. Au cours de cette étude, les nourrissons qui dormaient dans des conditions environnementales légèrement plus fraîches étaient plus enclins aux infections respiratoires durant les six premiers mois de leur vie. De plus, des études sur des nourrissons et leur mère dormant ensemble en laboratoire du sommeil, dans la même chambre ou le même lit, ont fait état d’interactions complexes entre les mères et les bébés assurant une thermorégulation efficace malgré des températures environnementales plus élevées lorsque les mères et les bébés partageaient le même lit.
T
hermal stress has been identified as a potential risk factor for sudden infant death syndrome (SIDS) (1-3), particularly in the presence of minor infections (4). We report a series of studies that aimed to identify the following:
• Whether bed sharing has any adverse effects on the thermoregulatory effectiveness of sleeping infants.
• Thermoneutral environmental conditions for sleeping infants in the first few months after birth;
Case-control studies of SIDS The Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI) study (4) was a large-scale, population-based study of all unexpected infant deaths that occurred in five regions in the United Kingdom over a three-year period. The study covered a population of 17 million people and included all deaths from 470,000 births. Of the 456 deaths that were identified, 325 met the definition of SIDS, and for each infant who died, four age- and locality-matched control infants were identified. Information was collected from case and control families during an interview. Additional information on thermal balance was available from an earlier study in the county of Avon (England) (2,5).
• The thermal conditions achieved by parents for their sleeping infants over the same age range; • Factors influencing parental choices concerning the thermal environment for their infants; • The effects of mother-infant proximity on the thermal environment experienced by sleeping infants; • How mothers assess and modulate the thermal environment of their sleeping infants; and
METHODS
Institute of Child Life and Health, United Bristol Healthcare Trust Education Centre, Bristol, United Kingdom Correspondence and reprints: Professor Peter Fleming, Institute of Child Life and Health, United Bristol Healthcare Trust Education Centre, Upper Maudlin Street, Bristol BS2 8AE, United Kingdom. Telephone 0044-117-342-0172, fax 0044-117-342-0193, e-mail
[email protected] Paediatr Child Health Vol 11 Suppl A May/June 2006
©2006 Pulsus Group Inc. All rights reserved
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Fleming et al
TABLE 1 Thermal resistance (tog value) of clothing and bedding typically used for infants Baby clothing and bedding Vest
Tog value* 0.2
Babygro
1
Jumper
2
Cardigan
2
Trousers Diaper (disposable) Sleeping suit
2 2 (dry),
