Ruiz-Sanz JI, et al. - Researchers performed an observational study of 64 women (age 19–46), consisting of unfertile patients and oocyte donors, undergoing controlled ovarian stimulation, to analyze in detail the fatty acid (FA) composition of follicular fluid (FF) from two-sized follicles at oocyte retrieval. Further, they examined the associations of the FAs from large follicles with the woman’s age and the response to ovarian stimulation. Thirty-two FAs were described in ovarian FF, of which 16 changed their distribution with follicle size. A better response to ovarian stimulation can be predicted with lower n-3 PUFA levels in large follicles, associated with younger women.