Maternal Mediterranean Diet Adherence During Pregnancy and Autism-Related Traits in Preadolescence: A Sex-Stratified...

Background: Maternal nutrition during pregnancy is increasingly recognized as an important determinant of offspring neurodevelopment. The Mediterranean diet has been associated with favorable cognitive and behavioral outcomes in children; however, evidence regarding autism-related traits remains limited, particularly during late childhood and adolescence. Objective: To investigate the association between maternal adherence to the Mediterranean diet during pregnancy and autism-related traits in preadolescent offspring in the KLOTHO birth cohort. Methods: This exploratory analysis included 96 adolescents (49 boys and 47 girls) from the KLOTHO birth cohort. Maternal adherence to the Mediterranean diet during pregnancy was assessed using a Mediterranean Diet Score derived from a food frequency questionnaire administered during gestation. Autism-related traits were evaluated during preadolescence using a parent-completed questionnaire that assessed social and emotional abilities, communication skills, cognitive characteristics, special interests, and motor skills. Associations were examined using Spearman's correlation analyses and sex-stratified linear regression models adjusted for offspring body mass index, sleep duration, and physical activity, all assessed during the preadolescent follow-up examination. Results: Boys exhibited higher communication (3.92 ± 3.90 vs. 1.70 ± 2.89, p = 0.026), cognitive (5.76 ± 3.80 vs. 3.33 ± 2.99, p = 0.014), special-interest (2.64 ± 3.29 vs. 1.04 ± 2.16, p = 0.046), and overall autism-related trait scores (19.08 ± 13.92 vs. 10.15 ± 8.57, p = 0.009) compared with girls. In the overall cohort, maternal Mediterranean Diet Score was not associated with autism-related traits. Among boys, higher maternal Mediterranean Diet Scores were associated with lower communication-related trait scores (ρ = -0.442, p = 0.027). In multivariable analyses, the inverse association remained consistent in direction but did not retain statistical significance after adjustment for body mass index, sleep duration, and physical activity. Sensitivity analyses incorporating offspring KIDMED scores yielded similar findings. Conclusions: Higher maternal adherence to the Mediterranean diet during pregnancy was associated with lower communication-related trait scores in male offspring. These findings should be considered exploratory and require confirmation in larger prospective cohorts.