Impact of antenatal exposure to pesticides on neurophysiological functions (sleep, respiration) of preterm neonates – PHYSIOMECO

Although the health effects of pesticides in man following acute intoxication are well known, little is known about the effects of chronic low-dose exposure. Furthermore, the paradigm concerning the dose-effect relationship is also increasingly contested, as the time of exposure now appears to be a very important factor in the development and severity of toxic effects. Pregnancy appears to be a particularly vulnerable period for the foetus in relation to exposure to environmental chemical aggressions such as pesticides. 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.
The PhysioMéco project is therefore designed to study the possible links between antenatal exposure to pesticides and modifications of sleep or respiratory control in preterm neonates. Antenatal exposure will be determined by pesticide assays in the meconium of neonates in combination with an exposure questionnaire to determine the sources of these pesticides. Sleep and respiratory control will be studied in these neonates nursed in incubators.