Background Caffeine is the most frequently used psychoactive substance in the United
States and> 90% of reproductive-age women report some amount of intake daily. Despite
biological plausibility, previous studies on caffeine and fecundability report conflicting
results. Importantly, prior studies measured caffeine exposure exclusively by self-report,
which is subject to measurement error and does not account for factors that influence
caffeine metabolism. Objectives Our objective was to examine associations between …