The influence of in utero exposure to smoking on sleep patterns in preterm neonates.
BACKGROUND
In utero exposure to smoking is known to adversely affect brain regions involved in behavioral state organization and could therefore interact with the neurophysiological development of neonates.


OBJECTIVE
The present study investigated the effects of prenatal smoking exposure on sleep patterns in the preterm neonate.


METHODS
Overnight sleep patterns were polysomnographically assessed at thermoneutrality. Sleep continuity and structure were scored for the respective frequencies, durations and percentages of active, quiet, and indeterminate sleep and wakefulness after sleep onset. The number and duration of body movements were also analyzed.


METHODS
The neonatal intensive care unit at Amiens University Medical Center (France).


METHODS
Healthy preterm neonates (postconceptional age: 33.9 +/- 6.0 weeks) were enrolled according to whether their mothers had not smoked at all during pregnancy (control group, n=19), smoked less during pregnancy (low-smoking group, Slow, n=10), or smoked more (heavy-smoking group, Sheavy n=10) than 10 cigarettes per day throughout pregnancy.


RESULTS
Neonates born to heavy-smoking mothers had a significantly lower mean birth weight than controls (-21%) and displayed disrupted sleep structure and continuity: they slept less overall (with a higher proportion of active sleep and a lower proportion of quiet sleep) and had more wakefulness after sleep onset. Compared with controls, neonates from both smoking groups displayed more body movements and, as a result, more disturbed sleep.


CONCLUSIONS
High prenatal smoking exposure modifies sleep patterns in preterm neonates by disrupting sleep organization and increasing nocturnal body movements. These findings raise the question of the repercussions of these sleep disturbances (at what is a critical stage in brain development) on the child's physiological and neurobehavioral outcomes.
Stéphan-Blanchard
Erwan
E
PériTox-INERIS Laboratory, Jules Verne University of Picardy, Amiens, France.
Telliez
Frédéric
F
Léké
Andre
A
Djeddi
Djamal
D
Bach
Véronique
V
Libert
Jean-Pierre
JP
Chardon
Karen
K
D001143:Arousal / Q000502:physiology; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000503:physiopathology*; D007363:Intensive Care Units, Neonatal; D009043:Motor Activity / Q000502:physiology; D017286:Polysomnography; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000503:physiopathology*; D012907:Smoking / Q000009:adverse effects*; D014851:Wakefulness / Q000502:physiology