Related Experiment Videos
Relations between the development of patterns of sleeping heart rate and body temperature in infants
S A Petersen1, C Pratt, M P Wailoo
1Department of Child Health and Division of Medical Education, University of Leicester, PO Box 138, Leicester, LE1 9HN, UK. sxp@leicester.ac.uk
Insights
Infant heart rate and rectal temperature patterns change abruptly, not gradually, as babies mature. Girls show a more pronounced heart rate shift, and parental smoking is linked to lower infant heart rates.
Area of Science:
- Pediatrics
- Developmental Biology
- Physiology
Background:
- Infant sleep physiology is complex and undergoes significant changes during early development.
- Previous research indicated abrupt shifts in rectal temperature patterns, but heart rate changes were less clear.
Purpose of the Study:
- To investigate the developmental patterns of overnight rectal temperature and heart rate in infants.
- To determine if changes in these physiological parameters occur gradually or abruptly.
- To explore sex differences and the impact of environmental factors like parental smoking on these patterns.
Main Methods:
- Overnight rectal temperature and heart rate were monitored weekly in 119 healthy infants from 7 to 16 weeks of age.
- Data were collected in the infants' home environment to ensure natural sleep conditions.
- Statistical analysis was used to examine developmental trends, sex differences, and the effect of parental smoking.
Main Results:
- Infants exhibited abrupt, rather than gradual, changes to adult-like night-time rectal temperature patterns at varying ages.
- Apparent gradual decreases in sleeping heart rate were an artifact of data collation; individual infants showed abrupt falls coinciding with temperature pattern shifts.
- Girls displayed a more abrupt and significant heart rate change concurrent with the development of the adult-like temperature pattern.
- Infants of parents who smoked had significantly lower heart rates after the adult-like temperature pattern emerged.
Conclusions:
- Infant sleep physiology, specifically heart rate and rectal temperature, undergoes abrupt developmental transitions.
- Sex-specific differences exist in the timing and magnitude of these physiological changes.
- Environmental factors, such as parental smoking, can influence infant heart rate development.
Abstract:
Overnight patterns of rectal temperature and heart rate were recorded from 119 normal infants at weekly intervals from 7 to about 16 weeks of age. All data were collected in the infants' own homes. As previously reported, different infants developed an adult-like night time rectal temperature pattern abruptly at different ages. When heart rate data were collated by age, there was an apparently gradual fall in sleeping heart rate from 7 to about 14 weeks of age. This was, however, an artefact of data collation. Individual infants showed abrupt falls in heart rate at the time that the adult-like body temperature pattern appeared, but this occurred at different ages in different babies, so when data were collated cross sectionally, an apparently gradual fall resulted. The relation between the developmental changes in sleeping heart rate and rectal temperature was different in boys and girls, with girls showing a more abrupt and greater change in heart rate at the time of development of the adult-like body temperature pattern. Infants whose parents smoked had significantly lower heart rates once the adult-like body temperature pattern had appeared.