Allswede DM, et al. - In view of the association of schizophrenia with pregnancy and birth complications and the possibility of fetal exposure to inflammation as a common underlying mechanism, researchers aimed at characterizing and comparing the longitudinal patterns of maternal serum concentrations of cytokines across pregnancy between offspring who were later discovered to have a psychotic disorder, non-psychotic siblings of these cases, and unrelated, non-psychotic individuals who served as controls. The impacts of perinatal factors on infant and child development were assessed in the National Collaborative Perinatal Project, a large-scale prospective longitudinal study. Enrollment of over 50 000 pregnant women was done during prenatal clinical visits at sites across the USA between 1959 and 1965. From the Philadelphia cohort, which includes 9,236 surviving offspring of 6,753 pregnant women, the present study was drawn. Via reviewing medical records, assessment of sychotic disorder diagnoses in adulthood was done; a validation study was undertaken to confirm the outcomes. A multiplex bead assay was performed on archived maternal serum samples collected across prenatal visits and birth for the concentrations of TNFα, IL-1β, IL-5, IL-6, IL-8, IL-10, and IL-17a. Ninety cases, 79 siblings (of 40 cases), and 273 matched controls were included in the final sample. In psychosis, a possible role of exposure to high maternal proinflammatory cytokine concentrations in early pregnancy was suggested in this study. These outcomes place the timing of risk linked with maternal inflammation much earlier in prenatal development than earlier documented in humans and present insight into a possible developmental pathway to the disease.