Maternal Diet and Offspring ASD and ADHD: A Critical Narrative Review of Dietary Patterns, Choline, and Polyphenol-Related Exposures.

Maternal diet may influence fetal neurodevelopment through nutrient availability, placental function, and maternal-fetal metabolite signaling. This critical narrative review used a structured, purposive search to organize human evidence on prenatal dietary patterns, choline, and polyphenol-related exposures according to outcome directness: diagnosed autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD), related dimensional traits, and general neurodevelopment. Whole-diet studies provide the most direct human evidence, but diagnostic findings are cohort-dependent and vulnerable to residual familial and genetic confounding. Choline trials and cohorts mainly address attention-related traits or general cognition; they do not establish prevention of diagnosed ASD or ADHD. Polyphenol evidence is limited to food proxies and one trimester-specific cohort of estimated intake, without diagnostic or biomarker-based studies. Preclinical data support biological plausibility-particularly for choline in BTBR, maternal immune-activation/CHRNA7, and Ts65Dn models and for resveratrol in valproate-exposed rodents-but remain model-specific. The evidence is therefore best treated as an organizing framework rather than a confirmed causal hypothesis. Clinical translation should prioritize achieving recommended dietary adequacy and balanced dietary patterns; evidence does not support high-dose single-nutrient or concentrated-polyphenol supplementation for ASD/ADHD prevention.