Association between Dietary Inflammatory Index and self‐reported female infertility from the National Health and Nutrition Examination Survey 2013‐2020

Abstract Background To explore the association between the diet inflammatory index (DII) and infertility. Methods Multivariable logistic regression was performed to investigate the relationship between infertility and DII, and restricted cubic spline (RCS) was utilised to test for nonlinear relationships in this cross‐sectional study. Data of this study were collected from the 2013 to 2020 National Health and Nutrition Examination Survey (NHANES) database. Considering women's child‐bearing age, we enrolled a total of 2066 women aged 20–45 years in this study. Results After all covariates were adjusted, a positive association was found between DII score and odds of infertility by multivariable logistic regression (odds ratio [OR] = 1.19, 95% confidence interval [CI] 1.03, 1.38; p = 0.027). Compared with participants with DII scores in the lowest quartile, those with DII scores in the highest quartile had significantly higher odds of infertility (OR = 2.42, 95% CI 1.09, 5.34; p = 0.034). The RCSs model suggested a linear relationship between DII and infertility ( p for nonlinear = 0.1827). Conclusions A positive association between a pro‐inflammatory diet and self‐reported infertility was detected. Our study extends the application of the DII scoring system to infertility prevention.