The Association Between History of Infertility and Dietary Practices: A Cross-Sectional Study Among Preconception Females

To evaluate the extent to which a history of infertility is associated with adherence to specific diets among reproductive-aged females.

Cross-sectional analysis

Between 2017–2023, 7,227 North American female pregnancy planners aged 21-45 years enrolled in PRESTO (Pregnancy Study Online), a preconception cohort study. Participants completed self-administered baseline questionnaires during preconception.

Infertility history, defined as: 1) self-reported 12-month clinical infertility, 2) history of visiting a clinician for an infertility work-up, and/or 3) clinician-identified cause of infertility (e.g., ovulatory or tubal).

Adherence to specific diets, including vegetarian, vegan, Mediterranean, Paleo, Weight Watchers®, ketogenic, dairy free, gluten free, Atkins®, South Beach®, Zone®, raw foods, or other at baseline. Multivariable log-binomial regression models estimated the prevalence ratios (PRs) and 95% confidence intervals (CIs), adjusted for age, income, and body mass index (BMI).

The percentage of participants with a history of infertility was 26% based on the 12-month clinical infertility definition, 30% based on visiting a physician for infertility evaluation, and 26% based on an infertility diagnosis following a physician visit. Overall adherence to any particular diet was low (4.6% vegetarian, 2.8% ketogenic, 1.7% Weight Watchers®, 1.4% Mediterranean, 1.3% vegan, 0.8% Paleo, and all other diets: <0.8%); 86.6% reported not adhering to any particular diet. A history of 12-month clinical infertility was associated with lower adherence to vegetarian (PR=0.78; 95% CI: 0.60-1.03), Paleo (PR=0.43; 95% CI: 0.19-0.98), and Weight Watchers® (PR=0.55; 95% CI: 0.34-0.91) diets. An infertility history involving a medical work-up was associated with a higher prevalence of adherence to a ketogenic diet (PR=1.56; 95% CI: 1.17-2.09). Participants whose infertility was attributed to ovulatory or tubal causes were nearly two times more likely to adhere to a ketogenic diet (PR=2.01; 95% CI: 1.38-2.94; PR=2.22; 95% CI: 1.09-4.49, respectively).

The cross-sectional design cannot establish temporality or causality. Data on dietary patterns and infertility history were self-reported, which can introduce misclassification. Generalizability may be limited because participants were pregnancy planners not using fertility treatments; participants were also more likely to be non-Hispanic White and of higher socioeconomic status than the general population.

The ketogenic diet was more prevalent among females with an infertility history, while vegetarian, Paleo, and Weight Watchers® diets were less prevalent. These associations mirror the results of studies evaluating the reverse relationship, suggesting that some patients with infertility seek information for behavioral modifications via evidence-based medicine.