Dietary inflammatory index is associated with female infertility: a cross-sectional analysis of the Fasa adults cohort study.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 42323645 · doi:10.1186/s40795-026-01404-2
What was done
This was a cross-sectional analysis of 2,036 women aged 35–45 years participating in the Fasa Adults Cohort Study in Iran. Dietary intake was assessed via a validated 118-item food frequency questionnaire to calculate Dietary Inflammatory Index (DII) scores based on 31 components. Infertility was defined as self-reported inability to conceive after at least 12 months of regular unprotected intercourse. Multivariable logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) for infertility according to DII, adjusting for age, educational level, BMI, waist circumference, smoking status, and total energy intake.
What was found
Among the 2,036 participants, 595 women (29.2%) reported a history of infertility. Mean DII score was significantly higher among women with infertility compared to fertile women. In the crude model, DII was not significantly associated with infertility. After multivariable adjustment, each one-unit increase in DII was associated with higher odds of infertility (adjusted OR = 1.29; 95% CI: 1.13–1.63).
Why it matters
This study provides observational evidence linking pro-inflammatory dietary patterns to female infertility in a Middle Eastern population, highlighting diet as a potential modifiable factor in female reproductive health.
Limits
The cross-sectional design cannot establish causality or temporal sequence. Infertility was assessed via self-report rather than medical records, DII calculation was limited to 31 dietary components, and unmeasured confounders (such as male-factor infertility or clinical gynecologic diagnoses) were not accounted for in the abstract.
Cited by
- supports Infertility is clinically defined as attempting to achieve pregnancy for 12 months without success.