ABSTRACT
INTRODUCTION Current practice of controlled ovarian stimulation (COS) for in vitro fertilization (IVF) has the possibility of using dierent protocols depending on the choice of the gonadotrophin-releasing hormone analog (GnRHa) and the diverse gonadotropin preparations (1). With regard to the latter, a major debate continues regarding using pure follicle-stimulating hormone (FSH)-alone regimens or administering some kind of luteinizing hormone (LH) activity-containing preparations.
