en Original Article Original Article <strong>Background:</strong> Female age and basal FSH level are independently associated with IVF outcome. They are both related to the same phenomenon, namely ovarian reserve.<br> <strong>Objective: </strong>To evaluate the effective role of serum FSH concentration at the start of treatment cycle on ART outcome.<br> <strong>Materials and Methods:</strong>&nbsp;A total of 207 women undergoing IVF and ICSI cycles were included in this study. Basal FSH concentrations were measured and the women&#39;s ages were calculated before they were undergoing pituitary desensitization and its correlation with ART outcome was evaluated.<br> <strong>Results: </strong>Increasing FSH was associated significantly with reduced number of follicles > 15mm, oocytes retrieved, and embryos obtained.<br> <strong>Conclusion: </strong>Age is the most important prognostic factor but basal serum FSH can be used to identify women who are very likely to perform poorly in ART, probably because of diminished ovarian reserve. Age, ART, Pregnancy outcome, Serum FSH. 19 0 http://ijrm.ir/browse.php?a_code=A-10-549-205&slc_lang=en&sid=1 Mohammad Ali Karimzadeh prof_karimzade @yahoo.com Yes Research and Clinical Center for Infertility, Yazd Shahid Sadoughi University of Medical Sciences, Yazd, Iran Sedigheh Ghandi No Department of Obstetric and Gynecology, Sabzevar University of Medical Sciences, Sabzevar, Iran