The heart rate variability assessment of the sympathetic-parasympathetic balance is a strong analytical tool in the autonomic nervous system (ANS) physiology, at each end of life.

In neonatology, it represents an important marker for understanding the breath and cardiac dysfunction, incriminated in the pathophysiology of unexplained death syndrome and apnea-bradycardia of prematurity.

If recent clinical studies conducted by our team highlight a close link between the maturation degree of the ANS and gestational or postnatal age, with a substantial autonomic dysfunction in preterm infants, no study to date has focused profile autonomic maturation in the first two years of life, as that period for the infant is a vulnerability "window" especially cardiopulmonary and neurological.

Psychomotor prognosis of newborns is more serious if prematurity is important and if periventricular leukomalacia or cortical anatomical brain lesions are obvious. However, the conventional imaging (Trans fontanel ultrasound, CT, MRI) is not sufficient in the neonatal period to thoroughly evaluate the neurological risk situations. During the neonatal period, the assessment of autonomic control, in practice easily quantifiable from time and frequency-domain analysis of cardiac RR variability, could be a strong marker, at a given time, from a neurological disorder undetectable by imaging, including sympathetic and parasympathetic nerve conduction dysfunction in some brainstem nuclei and cortical areas.

The postnatal profile of the autonomic balance, as a marker of well ANS regulation could become an additional support to correlate transient or permanent autonomic deficit with a psychomotor development disorder at 2 years of age or later. This tool could be a help to target the children with a neurological risk and to schedule early therapeutic interventions and psychological or educational support.

To meet this objective, we propose to describe for the first time in a cohort of newborns, the cardiac autonomic maturation profile in the first two years of life and the neurological evolution at 2 years.

Main objective.

• Describe the pattern, i.e. the cardiac autonomic maturation during the first two years of life in a cohort of newborns.

Secondary objectives.

• Correlate in this cohort, the autonomous status at birth to the neurological psychomotor status at 2 years.
• Describe the autonomic pattern (evolution profile) during the first two years of life.
• According to specific criteria of pregnancy (maternal smoking, maternal hypertension and gestational age)
• According to data of morphometry (stature and weight development) at birth.
• According to the neonatal morbidity criteria: - bronchopulmonary dysplasia i.e. oxygen dependence at 36 weeks postnatal age, persistent ductus arterious, intra ventricular haemorrhage according to the Papille classification, periventricular leukomalacia, enterocolitis, nosocomial sepsis.
• According to the incidence of serious faintness and rhythmic disorders the two first years of life.

Inclusion Criteria:

• Every child born in the CHU of Saint-Étienne (inborn), any term of its birth, in the hospital neonatal unit at the time of registration (after 37 weeks corrected for prematurity) or in the maternity
• Written consent signed by parents
• Parents affiliated in a Social Security regimen

Exclusion Criteria:

• History of intrafamilial dysautonomia
• Heart malformation, congenital abnormality of the brainstem
• Permanent troubles of heart rate
• Any therapy at the time of the study or made in the weeks preceding the study, referred to cardiac or respiratory or known to alter the activity of the ANS
• General anesthesia within 2 weeks prior to registration

Every child born in the CHU of Saint-Étienne (inborn), any term of its birth, in the hospital neonatal unit at the time of registration (after 37 weeks corrected for prematurity) or in the maternity