The pharmacology of ovarian stimulation has beenstrongly influenced by the two-cell, two-gonadotrophin theory while, historically, follicular stimulation protocols have included both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in an attempt to mimic normal physiology . During recent years, the effect of LH on follicular maturation and pregnancy outcome during the course of ovarian stimulation in relation to assisted reproduction has received increasing attention. The study enrolled 60 patients and showed that the addition of LH activity in controlled ovarian stimulation did not lead to a significant difference in the number of oocytes retrieved or the dose of gonadotropins or days of stimulation.