Abstract: The present invention discloses an unbiased “biomarker” method for the prediction of pregnancy success that is detectable in patient follicular fluid (FF) collected during egg retrieval in IVF procedures. Proteins that function in the cellular response to endoplasmic reticulum (ER) stress were measured in FF, and data generated using a de-identified, retrospective, unblinded cohort of human FF and matching demographic and pregnancy outcome data showed that FF levels of ER stress effector proteins GRP78 and CHOP, which are indicative of elevated ER stress in either the oocyte, granulosa cells, or other cells of the follicle, are causally related to poor pregnancy outcomes.