This has been a contentious topic in reproductive medicine, because it is assumed that too many patients undergo ICSI when they really do not necessarily have to. ICSI is a very reliable method of fertilization and allows picking the best-looking sperm. The typical fertilization rate is about 70-80% under normal conditions. At the other hand, it does create one more artificial step that might be attributed to potential health concerns. In particular, the ICSI has been linked with possibly contributing to increased occurrence of certain imprinting disorders. At Tree of Life Center, when we perform IVF in Los Angeles, we particularly take care not to do ICSI if we do not need it. We believe that natural fertilization in cases of normal sperm poses less risk to the offspring and avoids unnecessary manipulation of eggs and sperm. If we are worried that normally appearing sperm may not fertilize the eggs we might apply ICSI for only half of the eggs retrieved. We then try to use the conventionally fertilized embryos first and only if needed use the ones from the ICSI group.