# First–Second-Trimester Dietary Inflammatory Index and Anemia Risk in the Third Trimester: A Prospective Cohort Study

## TL;DR

This study finds that a pro-inflammatory diet during early pregnancy increases the risk of anemia in the third trimester.

## Contribution

It establishes a causal link between early-pregnancy dietary inflammation and later anemia risk in pregnant women.

## Key findings

- Pro-inflammatory diets in the first two trimesters were associated with a 3.73-fold higher risk of third-trimester anemia.
- Adjusting for multiple factors confirmed the significant correlation between dietary inflammation and anemia risk.
- The study suggests prenatal nutrition programs could reduce third-trimester anemia by targeting pro-inflammatory diets.

## Abstract

Objectives: Dietary conditions are closely related to maternal health. This study aims to investigate the causal relationship between the first–second-trimester Dietary Inflammatory Index (DII) and developing anemia in the third trimester. Methods: This prospective cohort study comprised 545 pregnant women, with dietary data assessed via a semi-quantitative food frequency questionnaire (FFQ). Hemoglobin levels were obtained by hospital laboratory tests and used to diagnose anemia. Multivariable logistic regression models—adjusted for baseline serum iron, age, pre-pregnancy body mass index (BMI), occupation, education, history of adverse pregnancy outcomes, parity, serum iron, passive smoking exposure, and iron supplementation use during pregnancy—were employed to evaluate the relationships between the first-trimester DII, second-trimester DII, first–second-trimester average DII, and third-trimester anemia. Results: After multivariable adjustment, the first–second-trimester average DII in the pro-inflammatory diet group demonstrated a 3.73-fold elevated risk of third-trimester anemia compared to the anti-inflammatory diet group (Odds Ratio [OR] = 3.73, 95% Confidence Interval [CI]: 1.50–9.25). Conclusions: Pro-inflammatory dietary patterns during pregnancy exhibit a significant correlation with developing third-trimester anemia. This study demonstrates that reducing dietary pro-inflammatory components through prenatal nutrition programs may lower third-trimester anemia risk. Notably, this study carries potential risks of bias, including self-reporting bias in dietary data and incompletely controlled confounding factors (such as unmeasured biomarkers).