Preconception dietary inflammatory index and hypertension disorders of pregnancy: The Japan environment and children's study.

ABSTRACT

OBJECTIVE: We aimed to examine the impact of preconception pro-inflammatory diet on hypertensive disorders of pregnancy. STUDY DESIGN: Data from the Japan Environmental Children's Study (JECS), a nation-wide birth cohort study, were used. MAIN OUTCOME MEASURES: Information on meal patterns before pregnancy, derived through food frequency questionnaires, was used to calculate the dietary inflammatory index. Based on the dietary inflammatory index, participants were categorized into quartiles (Q1 and Q4 representing the diet with the highest anti-inflammatory and pro-inflammatory effects, respectively), and a multiple logistic regression model was used to estimate the effect of pro-inflammatory diet on hypertensive disorders of pregnancy, early-onset-hypertensive disorders of pregnancy, late-onset-hypertensive disorders of pregnancy, and hypertensive disorders of pregnancy with/without small for gestational age birth. RESULTS: After applying our inclusion criteria, 93,265 participants were eligible. The mean white blood cell count during the first trimester and urine 8-hydroxy-2'-deoxyguanosine levels during pregnancy were highest in the Q4 group (both p < 0.01). Multiple regression analysis showed that pro-inflammatory diet consumption increased the risk of both early-onset-hypertensive disorders of pregnancy (adjusted odds ratio 1.53, 95% confidence interval 1.06-2.20) and hypertensive disorders of pregnancy without small for gestational age birth (adjusted odds ratio 1.26, 95% confidence interval 1.03-1.54) among multiparous women. CONCLUSION: Consumption of diet with a high dietary inflammatory index score before pregnancy increases maternal inflammation and oxidative stress during pregnancy. Preconception lifestyle influences the risk of hypertensive disorders of pregnancy, especially among multiparous women.