Résumé : Objective: To report two cases of coasting during receipt of GnRH antagonists. Design: Case report. Setting: University hospital. Patient(s): One 27-year-old and one 28-year-old woman, both with risk factors for the ovarian hyperstimulation syndrome (OHSS). Intervention(s): Two IVF treatments during which hMG treatment was stopped until E2 decreased to a safer level during receipt of GnRH antagonist. Main Outcome Measure(s): Development of OHSS and pregnancy. Result(s): Embryos were transferred in both women. Neither woman developed OHSS and one ongoing pregnancy was obtained. Conclusion(s): Coasting is feasible when a GnRH antagonist is used during IVF. Further studies are needed to evaluate its preventive role in OHSS. © 2001 by American Society for Reproductive Medicine.