During pregnancy, the foetus is therefore chronically exposed to a large number of substances. A number of studies have started to emphasize the effects of this antenatal exposure on the newborn infant's morphological parameters (weight, crown-rump length, etc.). However, in addition to these morphological effects, pesticides may also induce various effects on physiological functions, as some pesticides act as inhibitors of neurotransmitters involved in many nervous system regulation pathways in man. This is particularly the case for organophosphates, which act as acetylcholinesterase inhibitors. A previous study conducted by the coordinator of the project presented here demonstrated the presence of high levels of this type of pesticide in meconium (1st stool) in neonates born in Picardy. This inhibition of the enzyme metabolizing ACh could have an impact on neurophysiological functions mediated by this neurotransmitter. Sleep or respiratory control, vital functions of the neonate particularly in preterm neonates, could therefore be affected.