Context: Latest findings (Styer AK, 2016) show that changes in anti-müllerian hormone (AMH) level during ovarian stimulation can predict the outcome. In his study women with minimal AMH decline produced fewer oocytes and had lower chances to achieve pregnancy. An animal model, unpublished data from Aritro Sen, shows AMH suppression by FSH level. Objective: To evaluate the dynamic of changes in AMH serum concentration during the course of controlled ovarian stimulation (COH) and its link with COH and pregnancy outcomes. Methods: Prospective cohort study performed at Invicta Fertility Clinic. AMH serum concentration was measured with automated VIDAS AMH (bioMérieux) by ELFA (Enzyme Linked Fluorescent Assay). Patient(s): 30 fresh cycles with embryo transfer from Aug to Oct 2016 were analyzed. Intervention(s) Series of AMH measurements were made for every patients during COH from the day 1 of stimulation (1ds) until day of oocytes retrieval (DOR). Main Outcome Measure(s): Relation between AMH change and response to COH and clinical pregnancy outcome. Result(s): We evaluated AMH level at 3 time points during COH. Between 1ds and DOR we observed an average drop in AMH concentration by 59%, then further decline by 32% between 1ds and 8ds and another 39% drop from 8ds until DOR. We found moderate correlation between size of AMH decline (ng/ml) between 1ds and DOR and the number of follicles after stimulation (r = 0,44615). No relationship was found between magnitude of AMH decline and pregnancy outcome. Conclusions: We confirmed the significant AMH decline during COH. Some authors suggest inhibition of AMH by exogenous FSH used during COH, but in this study AMH level decline continued after 8ds when FSH administration was already completed. Additionally, use of the new automated assay available for point of care usage allows better access to fast and accurate AMH testing.