Lehert P, Arvis P, Avril C, et al. - Researchers herein examined the utility of the Poor Responder Outcome Prediction (PROsPeR) score in predicting live birth outcomes using in subpopulations of patients with poor ovarian response (POR) defined according to the ESHRE Bologna criteria [female age, anti-Müllerian hormone (AMH), number of oocytes retrieved during the previous cycle (PNO)] after treatment with originator recombinant human follitropin alfa. Data from the follitropin alfa (GONAL-f; Merck KGaA, Darmstadt, Germany) arm of the Efficacy and Safety of Pergoveris in Assisted Reproductive Technology (ESPART) randomized controlled trial (RCT) were used to develop the PROsPeR score; this score classifies women with POR as mild, moderate or severe, based upon three variables: female age, serum AMH level and number of oocytes retrieved during the previous cycle (PNO). Data derived from eight different centres in France were used to complete the external validation of the PROsPeR score. Furthermore, they used the follitropin alfa data from the ESPART RCT, originally utilized to develop the PROsPeR score, as the reference cohort. Data from 8,085 ART treatment cycles performed with follitropin alfa in patients with POR defined according to the ESHRE Bologna criteria (17.6% of the initial data set) were included in the observational cohort. A total of 477 ART treatment cycles with ovarian stimulation performed with follitropin alfa in patients with POR were included in the ESPART cohort. Per findings, the PROsPeR score led to discrimination of the probability of live birth in patients with POR utilizing observational data with fair discrimination (AUC ≅ 70%) and calibration, and the AUC losing less than 5% precision compared with a model created using the observational data.