If the male's sperm count is low, or exhibits poor motility (ability to move about), fertilization may fail to occur with standard IVF techniques. For these patients, and for patients who have poor or absent fertilization In Vitro, Intracytoplasmic Sperm Injection (ICSI) is a significant breakthrough. In ICSI, a single sperm is picked up in a microscopic needle and injected directly into the center of the egg. Since ICSI can be employed even when the semen contains only a very few motile sperm, ICSI may offer an otherwise infertile male a very real chance of becoming a biological parent.

In some cases, in men who ejaculate no sperm at all, sperm cells can be directly removed from the testicles to be used via ICSI to fertilize the wife's eggs. With the advent of ICSI, many couples now have the possibly of achieving pregnancy without resorting to the use of donor semen (AID).