ABSTRACT: Background:Some dietary factors have been linked to outcomes of infertility treatment with assisted reproductive technology (ART), but the role of intake of meats and other protein-rich foods remains unclear. Objective:The aim of this manuscript was to study the relation between preconception intake of meat and other protein-rich foods and outcomes of infertility treatment with ART. Design:A total of 351 women enrolled in a prospective cohort at the Massachusetts General Hospital Fertility Center and underwent 598 ART cycles for infertility treatment. Meat intake was assessed with a validated food-frequency questionnaire, and ART outcomes were abstracted from electronic medical records. We estimated the associations between intake of protein-rich foods (meats, eggs, beans, nuts, and soy) and the outcome of live birth per initiated cycle using generalized linear mixed models. Results:The average total meat intake was 1.2 servings/d, with most coming from poultry (35%), fish (25%), processed meat (22%), and red meat (17%). Fish intake was positively related to the proportion of cycles resulting in live birth. The multivariable-adjusted probabilities of live birth for women in increasing quartiles of fish intake were 34.2% (95% CI: 26.5%, 42.9%), 38.4% (95% CI: 30.3%, 47.3%), 44.7% (95% CI: 36.3%, 53.4%), and 47.7% (95% CI: 38.3%, 57.3%), respectively (P-trend = 0.04). In the estimated substitution analyses, the ORs of live birth associated with increasing fish intake by 2 servings/wk were 1.54 (95% CI: 1.14, 2.07) when fish replaced any other meat, 1.50 (95% CI: 1.13, 1.98) when fish replaced any other protein-rich food, and 1.64 (95% CI: 1.14, 2.35) when fish replaced processed meat. Conclusions:Fish consumption is related to a higher probability of live birth following infertility treatment with ART. This trial was registered at clinicaltrials.gov as NCT00011713.