NEONATAL SOCIETY ABSTRACTS
The development of thermoregulation in a harsh environment: A prospective controlled study of the effects of swaddling on infants’ thermal balance in a Mongolian winter
Presented at the Neonatal Society 2005 Summer Meeting (programme).
Tsogt B1, Maniseki-Holland S2, Pollock J1, Blair P3, Fleming P3
1 University of the West of England, UK
2 London School of Hygiene & Tropical Medicine, London, UK
3 Institute of Child Life & Health, University of Bristol, Bristol BS2 8AE3, UK
Background: Traditional infant care in Mongolia includes tight swaddling in multiple layers, including partial head covering with hats, during both day and night, throughout the winter. Infants usually sleep under adult bedding, in the same bed as mothers, and swaddling is usually continued until around 7 months of age. Many families live in traditional circular tents called “ger”, with a single room, and no heating overnight, when outdoor temperatures commonly fall below -40ºC. The high incidence of respiratory infections in infants has been attributed to tight swaddling with restricted chest movements, though the role of thermal stress is not known.
Objective: To investigate thermal balance at home of infants in a Mongolian winter, and to compare the effects of swaddling with the effects of an infant sleeping bag of equal thermal resistance.
Methods: 1274 healthy term infants were randomly allocated to swaddled or non-swaddled groups (using sleeping bags of equivalent thermal resistance), within 48 hours of birth. Digital recordings of infants’ core, peripheral and environmental temperatures at 30 second intervals were made from 40 swaddled and 40 non-swaddled infants over 24 hour periods, at 1 month and 3 months of age, between December and March. Mothers recorded detailed logs of infant activity and wrapping.
Results: Temperature recordings suitable for analysis were obtained from 79 infants at both 1 and 3 months. Most infants bedshared with parents and slept under heavy adult bedding as well as the swaddling or sleeping bag. Indoor environmental temperatures during the night commonly fell below 0ºC, and temperatures in the late afternoon (during cooking) commonly rose to above 25°C, but no episodes of hyper- or hypo- thermia were recorded. Median indoor environmental temperatures were no different for the studies at 1 month and those at 3 months. No differences were identified at either age between environmental, peripheral or core temperatures during either day or night, awake or asleep, for swaddled vs non-swaddled infants. For swaddled and non-swaddled infants during sleep at night at 1 month, median core temperatures (37.0, 36.6) and peripheral temperatures (35.5, 35.2) were significantly higher than those at 3 months (36.2, 36.0 and 29.2, 29.8 respectively) (all p<0.0001, [Wilcoxon]). Similar differences were noted during daytime sleep periods.
Discussion: Despite the harsh environmental conditions, heavy wrapping, bedsharing and head covering, all infants showed effective thermoregulation whether swaddled or in infant sleeping bags. Swaddling offered no thermal advantages over the sleeping bag. The lower core and peripheral temperatures in the older infants reflect the development of the normal fall in body temperature during sleep, particularly at night. These results shed important light on the ability of normal infants to effectively thermoregulate, and to safely achieve normal diurnal falls in core temperature during sleep, despite extreme environmental temperature changes, very high levels of extrinsic insulation, and bedsharing with parents and/or siblings.