||Should Neonates Sleep Alone?
, and |
||Heart rate variability, hidden regulators, maternal-ne-
onate separation, skin-to-skin contact, sleep, stress
||Background: Maternal-neonate separation (MNS) in mammals is a model for studying the effects of stress on the development and
function of physiological systems. In contrast, for humans, MNS is a Western norm and standard medical practice. However, the physiological
impact of this is unknown. The physiological stress-response is orchestrated by the autonomic nervous system and heart rate variability
(HRV) is a means of quantifying autonomic nervous system activity. Heart rate variability is influenced by level of arousal, which can be
accurately quantified during sleep. Sleep is also essential for optimal early brain development.
Methods: To investigate the impact of MNS in humans, we measured HRV in 16 2-day-old full-term neonates sleeping in skin-to-skin
contact with their mothers and sleeping alone, for 1 hour in each place, before discharge from hospital. Infant behavior was observed
continuously and manually recorded according to a validated scale. Cardiac interbeat intervals and continuous electrocardiogram were
recorded using two independent devices. Heart rate variability (taken only from sleep states to control for level of arousal) was analyzed in
the frequency domain using a wavelet method.
Results: Results show a 176% increase in autonomic activity and an 86% decrease in quiet sleep duration during MNS compared with
Conclusions: Maternal-neonate separation is associated with a dramatic increase in HRV power, possibly indicative of central anxious
autonomic arousal. Maternal-neonate separation also had a profoundly negative impact on quiet sleep duration. Maternal separation may
be a stressor the human neonate is not well-evolved to cope with and may not be benign.