Success varies with many factors. The age of the woman is the most important factor, when women are using their own eggs. Success rates decline as women age, specifically after the mid-30’s.  Part of this decline is due to a lower chance of getting pregnant from ART, and part is due to a higher risk of miscarriage with increasing age, especially over age 40.  

Success rates vary with the number of embryos transferred. However, transferring more and more embryos at one time does not increase the chance of live birth significantly, but may only increase the risk of a multiple pregnancy, and its associated risks. The impact of the number of embryos that are transferred also varies with the age of the woman.