Background: The use of recombinant human follicle-stimulating hormone (r-hFSH) in ovarian stimulation protocols for infertility treatment in assisted reproductive technology (ART) clinical practice is well established. More recent advancements include the availability of biosimilar r-hFSH products, which expand the choices available to healthcare practitioners and patients. Better understanding of how such a product contributes to routine clinical practice is valuable to help prescribers make informed treatment choices. The objective of this study was to examine the effectiveness and safety of ovarian stimulation (OS) with follitropin alfa (Ovaleap®) for routine IVF or intracytoplasmic sperm injection treatment in gonadotropin-releasing hormone (GnRH) antagonist cycles in real-world ART clinical practice.Methods: This non-interventional, multicenter, prospective study was initiated in 34 specialized reproductive medicine centers in Germany. Eligible women were 18-40 years old with a body mass index < 30 kg/m 2 , menstrual cycle 24-35 days and anti-Müllerian hormone ≥1 ng/mL, who were undergoing a first OS cycle exclusively with Ovaleap® during routine ART using a GnRH antagonist protocol. Primary effectiveness outcomes were number of retrieved oocytes after OS and clinical pregnancy rate (CPR). Secondary outcomes included fertilization rate, number of transferred embryos, live birth delivery rate, safety, and user satisfaction with the Ovaleap® pen.