Clinical Research Directory

Inclusion Criteria: * expression of written informed consent * an antibiotic treatment (any molecule) for at least 7 days consecutively after the 32 weeks of pregnancy (or the absence of exposure to any systemic antibiotic treatment during pregnancy for the control group) * the intention to breastfeed their neonates as long as possible during the first year of life Exclusion Criteria: * absence of written informed consent * the intention to formula feed exclusively (or the presence of significant maternal concerns about breastfeeding) * a maternal antibiotic treatment shorter than 7 days * the presence of pre-existing maternal immune-mediated disorders (including immunodeficiencies and chronic infectious diseases) * a delivery at a gestational age \< 34 weeks * the administration of antibiotics to neonates after birth, within the first week of life.