Journal of Knowledge & Health1735-577X14120190618The Effect of Progesterone Administration on the Number of Secondary Follicles of Ovulated Mice During Pre-Implantation515510.22100/jkh.v14i1.2193FALeilaORCID:0000-0002-3295-9086Narimani. leila.narimani@yahoo.comNasimORCID:0000-0002-4205-8169Beigi BoroujeniMohamad RezaORCID:0000-0003-3719-1659GholamiKhaterehORCID:0000-0002-6468-3053AnbariMitraORCID:/0000-0001-9691-3012ArianmaneshMandanaORCID:0000-0003-2276-3554Beigi Boroujeni201902242019061620190615Introduction: Ovulation induction using gonadotropins increases the progesterone at the end of follicular phase and subsequently has a negative effect on the outcome of ovulation induction. The aim of this study was evaluation of the effect of progesterone administration on the number of secondary follicles on ovulationMethods: In this study, 15 adult female rats were randomly divided into three groups: control, ovulation induction group and ovulation induction group with progesterone administration. In experimental groups, ovulation stimulation was performed with hMG and hCG, and then false pregnancy was induced in all three groups. In Experimental group 2, after induction of pregnancy, 1 mg progesterone daily was injected. For histological examination, ovarian samples were taken from all three groups at the time of pre-implantation and statistical analysis perforemd.Results: The number of secondary follicles in experimental groups 1 was significantly higher than the experimental group 2 and control group (P<0.05). However, there was no significant difference in the experimental group 2 compared to the control group.Conclusion: Progesterone administration after ovulation stimulation inhibits folliculogenesis and thus prevents excessive ovarian stimulation syndrome. Progesterone administration balance ovulation stimulation.