Iron Adequacy Modifies the Association Between Prenatal Diet Quality and Pregnancy-Related Anxiety in Pregnant Women:...

Diet quality may influence maternal psychological well-being through nutrients involved in neurotransmitter synthesis and brain energy metabolism. Iron may be particularly relevant because its requirements increase during pregnancy; however, whether dietary iron adequacy modifies the association between prenatal diet quality and pregnancy-related anxiety remains unclear. This study examined the association between prenatal diet quality and pregnancy-related anxiety and whether dietary iron adequacy moderated this relationship. This cross-sectional study included 293 pregnant women in Istanbul, Türkiye (mean age: 29.60 ± 4.29 years). Prenatal diet quality was assessed using the Prenatal Diet Quality Index (PDQI), anxiety using the Pregnancy-Related Anxiety Scale (PRAS), and dietary iron adequacy as the percentage of the Recommended Dietary Allowance met through dietary intake. Moderation analysis was performed using multiple linear regression adjusted for sociodemographic and obstetric covariates. The mean PRAS score was 70.44 ± 16.07 on a scale of 33-132, and the mean PDQI score was 42.76 ± 9.73 out of 80. As no established cut-off values were available, scores were not classified as high or low. PDQI and dietary iron adequacy were not independently associated with anxiety; however, their interaction was significant (B = -2.501, p = 0.007). Higher diet quality was associated with lower anxiety only among women with relatively high dietary iron adequacy. Maternal age, income, and planned pregnancy were also independently associated with anxiety (p < 0.001). The association between prenatal diet quality and pregnancy-related anxiety may vary according to dietary iron adequacy. However, as iron was the only nutrient-specific moderator assessed and biochemical iron status was not measured, the findings do not establish a unique or causal role for iron. Future longitudinal studies should evaluate multiple micronutrients using biomarker-based measures.