['The strong relationship between serum anti-Müllerian hormone (AMH) levels and the number of antral follicles supports the use of AMH measurements as a quantitative marker of the ovarian follicular status. Yet, it still is unclear whether the aptitude of an individual follicle to produce AMH reflects its reproductive competence.', 'This study examined the possible relationship between serum or follicular fluid (FF) AMH concentrations and the fate of the ensuing oocytes and embryos obtained by in vitro fertilization-embryo transfer conducted in monodominant follicle cycles.', 'We conducted a prospective study at the University of Paris XI, Assistance Publique-Hôpitaux de Paris, Institut National de la Santé et de la Recherche Médicale U782.', 'Patients included 118 infertile in vitro fertilization-embryo transfer candidates.', 'Concentrations of AMH, progesterone, and estradiol were measured in the serum on cycle d 3 and on the day of oocyte pickup (dOPU), and in FF. Cycles were sorted into three sets of three distinct groups according to whether serum d 3, serum dOPU, and FF AMH concentrations were 30th centile or below (low AMH), between the 31st and the 70th centiles (average AMH), or above the 70th centile (high AMH) of measurements.', 'Clinical pregnancy and embryo implantation rates were assessed.', 'Clinical pregnancy rates (5.7, 20.0, and 39.5%, respectively; P < 0.002) and embryo implantation rates (11.8, 30.8, and 65.4, respectively; P <0.001) were markedly different among the low, moderate, and high FF AMH groups but not among the serum (d 3 or dOPU) AMH groups. Fertilization rates and embryo morphology remained similar irrespective of AMH concentrations in the serum or in FF. Incidentally, FF AMH concentrations were negatively correlated with FF progesterone (r = -0.27; P <0.003) and FF estradiol (r = -0.21; P <0.02) concentrations.'] Are anti-Müllerian hormone concentrations in the follicular fluid of the preovulatory follicle predictive of the implantation potential of the ensuing embryo obtained by in vitro fertilization?