The programming role of maternal antenatal inflammation on infants’ early neurodevelopment: A review of human studies: Special Section on “Translational and Neuroscience Studies in Affective Disorders” Section Editor, Maria Nobile MD, PhD

Background: Maternal inflammation during pregnancy is a frequently proposed mechanism underlying the link between maternal antenatal physical (e.g. infections, immune disease, obesity) and/or psychological (e.g. depression, anxiety) conditions and child outcomes. However, the extent to which maternal inflammation is directly associated with offspring's early development and health in humans remains largely unknown. Methods: In this review, empirical findings on the prospective association between maternal prenatal levels of inflammatory markers and infants’ neurodevelopmental outcomes are summarized. Fifteen studies were included with sample sizes ranging from 36 to 6016 mother-infant dyads and average overall quality score 9.53 (range 6–12). Results: Findings concerning the link between maternal antenatal inflammation and, respectively, infants’ health and birth outcomes, stress reactivity or cognitive development are mixed. However, it is noteworthy that all higher quality studies (scores >10) reviewed here do find evidence of an association between levels of inflammation, mostly as indexed by Interleukin-6 (IL-6), in healthy women across the whole gestation and offspring's neurodevelopmental outcomes, including structural and functional brain alterations. Limitations: The correlational nature of the findings and conspicuous methodological heterogeneity across studies make drawing strong conclusions premature. Conclusions: Findings, albeit preliminary, are consistent with animal studies and speak in favor of a role of maternal antenatal inflammation in shaping fetal development with possible long-term effects.