A few hours after egg retrieval, the eggs are inseminated. This is accomplished by culturing the eggs and sperm together in a sterile dish within a specialized incubator, which tightly controls environmental conditions to best promote normal fertilization.
In many cases, an additional procedure known as intracytoplasmic sperm injection (ICSI) is required to increase the chances of fertilization. ICSI employs micromanipulation techniques to inject a single sperm into each egg. The day after retrieval, the eggs are evaluated to determine how many have been fertilized.
