What is the success rate with frozen/thawed embryos?
As with in vitro fertilization involving fresh embryos, the age of the egg provider is the single most important predictor of outcome. For embryos frozen on Day 3, approximately 70% will survive the freeze/thaw process. This may be higher for embryos frozen on Day 5 (blastocysts). The implantation rate for a successfully thawed Day 3 embryo would then be dependent on the maternal age of the egg donor. For women under 35, if two successfully thawed Day 3 embryos are transferred, the chances of pregnancy would be between 30 and 40%. These are therefore slightly lower pregnancy rates than would be seen with a fresh cycle. The success rates will decline as age advances.
