Purpose: To determine the relative effect of age vs ovarian oocyte reserve on miscarriage rates. Materials and Methods: Miscarriage rates (loss of pregnancy established by ultrasound) from pregnancies achieved through in vitro fertilization-embryo transfer (IVF-ET) were evaluated according to four age groups (≤ 35, 36-39, 40-42, and 43-44 years) and four day 3 serum follicle-stimulating hormone (FSH) groups (≤ 11, 12-14, 15-17, and > 17 mIU/ml). All cycles were supplemented with progesterone in the luteal phase. Results: With each advancing age group irrespective of the FSH levels, there was a progressive increase in miscarriage rates. In contrast, no difference in miscarriage rates were seen as FSH levels increased (and thus ovarian reserve decreased) in women up to 42 years of age. Only in the group aged 43-44 years was there an association with diminished oocyte reserve and miscarriage. Conclusions: Since low FSH stimulation protocols were purposely used for the group with diminished oocyte reserve, the data are consistent that the conclusion regarding poor oocyte quality in women with diminished oocyte reserve was mostly iatrogenic and related to the use of highdosage FSH stimulation trying to create more oocytes for retrieval.