[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine whether the bone-morphogenetic proreins-2 (BMP-2) or-7 (BMP-7) levels in follicular fluid (FF) are associated with success in oocyte fertilization during assisted reproductive technology (ART) treatment. Twenty-four cycles in 24 patients who underwent oocyte retrieval in Sugiyama clinic were included in this retrospective study. The patients were divided into two groups according to the success or failure of fertilization. FF samples were obtained from a single follicle in each patient, and the levels of BMP-2, BMP-7, Anti-Müllerian hormone (AMH), estradiol and progesterone from FF were measured, and evaluated in relation to the ART outcomes. The BMP-2 levels correlated positively with the AMH levels in FF (r
2 = 0.4928), but there was no statistically significant difference between BMP-7 and AMH levels. The BMP-2 and BMP-7 levels had no relation with either progesterone or estradiol levels, but BMP-2 levels in the fertilized group were significantly higher than those in the unfertilized group (P < 0.05). The BMP-2 levels in FF positively correlated with the AMH levels in FF, and those in the fertilized group were significantly higher than in the unfertilized group. Therefore, the BMP-2 levels in FF could be a predictive marker for fertilization.