Intracytoplasmic sperm injection, an in vitro procedure directly injecting the sperm into the egg then the egg is returned to the woman’s body, is the technique most commonly used to fertilize the infertile man’s partner.
Typically, a harvested sperm injected into an egg successfully fertilizes the egg thirty-seven to forty-eight percent of the time. When such fertilization has been observed and the egg placed back into the woman, pregnancy occurs about thirty percent of the time.
Those rates are actually very similar to the rates seen during attempts for natural conception. MESA and ICSI may be less convenient than the natural method, but still offer good success as an alternative.