Effect of an Antenatal Lifestyle Intervention on Dietary Inflammatory Index and Its Associations with Maternal and Fetal Outcomes: a Secondary Analysis of the PEARS Trial

We investigated the effect of an antenatal lifestyle intervention of a low‐glycaemic index (GI) diet and physical activity on energy‐adjusted dietary inflammatory index (E‐DIITM) and explored its relationship with maternal and child health in women with overweight and obesity. This was a secondary analysis of 434 mother‐child pairs from the Pregnancy Exercise and Nutrition Study (PEARS) trial in Dublin, Ireland. E‐DIITM scores were calculated for early (10‐16 weeks) and late (28 weeks) pregnancy. Outcomes included lipids, inflammation markers, insulin resistance, mode of delivery, infant size, pre‐eclampsia, and gestational diabetes. T‐tests were used to assess changes in E‐DIITM. Chi‐square, correlations, and multiple regression were employed to investigate relationships with outcomes. The mean (SD) age of participants was 32.45 (4.29) years with median (IQR) BMI 28.25 (26.70, 31.34) kg/m2. There was no change in E‐DIITM in the controls (‐0.14 (1.19) vs. ‐0.07 (1.09), p = 0.465) but E‐DIITM reduced by 10% after the intervention (0.01 (1.07) vs ‐0.75 (1.05), p < 0.001). No associations were found between early pregnancy E‐DIITM and maternal and child outcomes, except for increased odds of adverse cardiometabolic phenotype in women who delivered male (OR = 2.29, p = 0.010) but not female infants (OR = 0.99, p = 0.960). A low‐GI antenatal intervention can reduce the inflammatory potential of diets. Sex differences should be explored further in future research.