['Antidepressant treatment during pregnancy is speedily increasing in developed countries and this phenomenon has occurred without firm evidence on safety and/or efficacy.', 'The present study investigated from mid-trimester of pregnancy up to 24 hours after birth the pattern of a brain damage marker, namely S100B, in maternal fetal and neonatal biological fluids of pregnant women and their newborns antenatally treated by antidepressant drugs such as selective serotonin re-uptake inhibitors (SSRI).', 'we conducted an observational study on 75 pregnant women treated in the mid -third trimester by antidepressant drugs and 231 healthy pregnancies. S100B concentrations were measured at 7 predetermined monitoring time-points before, during and after treatment in maternal, fetal and neonatal biological fluids and correlated with neurological follow-up at 7 days from birth.', 'In SSRI group S100B concentrations were significantly higher in SSRI than controls (P<0.001, for all) in maternal blood, in amniotic fluid, in arterial and venous cord blood and at 24-h from birth. Highest (P<0.05) S100B levels were found in SSRI infants showing major neurological symptoms at 7-d follow-up.'] Do antenatal Maternal Antidepressants Drugs Affect S100B Concentrations in Fetal-Maternal Biological Fluids?