Epigenetic Mechanisms Linking Prenatal Maternal Stress to Child Neurodevelopmental Outcomes in Lagos State: A Biosocial Approach

This study investigates epigenetic mechanisms through which prenatal maternal stress influences neurodevelopmental outcomes in children, applying a biosocial developmental framework to a prospective cohort in Lagos State, South West Nigeria. While prenatal stress has been linked to adverse neurodevelopment in experimental and epidemiological studies globally, evidence from West African populations incorporating biological mechanisms remains extremely limited. This research followed 350 pregnant women recruited from antenatal clinics at Lagos University Teaching Hospital and Massey Street Children's Hospital from the second trimester through the child's third year of life. Maternal stress was assessed using the Perceived Stress Scale and biological stress markers via salivary cortisol at three prenatal timepoints. Umbilical cord blood samples were collected at delivery for methylation analysis of key stress-sensitive gene loci. Neurodevelopmental outcomes at 12, 24, and 36 months were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition. Hierarchical linear modelling and mediation analysis examined direct stress effects and methylation-mediated pathways. Results indicate that elevated prenatal stress predicts poorer cognitive and language outcomes at 24 and 36 months, with differential DNA methylation at NR3C1 and BDNF loci partially mediating these effects. Socioeconomic adversity amplified the biological embedding of stress. The study constitutes an original biosocial contribution to developmental psychology in sub-Saharan Africa and recommends prenatal stress reduction as a priority target for developmental intervention in Lagos State. Keywords: epigenetics, prenatal stress, neurodevelopment, biosocial development, Lagos State.