Response of Preterm Infants to Multisensory Stimuli

The aim of this study is to measure the variation of oxytocin and cortisol levels in the saliva of neonates with gestational age ranging from 32 to 34 completed weeks and in the saliva of their mothers. The measurements are taken before and after sensorial stimuli including mother voice exposure +/- tactile distraction for 10 minutes. The two interventions are performed between day 5 and day 12 after birth and 24 to 48 hours apart. Each child is randomised in a group depending on order of the two interventions. Investigators hypothesize that an increase in the oxytocin/cortisol ratio will be occurred in neonates after hearing their mothers and that simultaneous tactile stimulation will mitigate that effect. Concomitantly, the neonate's vital signs and his facial expressions are recorded during interventions. The mothers anxiety level is assessed PSS-NICU questionnaire given before the first and after the second intervention.