Intracytoplasmic Sperm Injection (ICSI) is a laboratory technique that has revolutionized the treatment of male factor infertility. For some men the sperm are too few in number or the sperm are misshapen which prevents the penetration of the egg by the sperm. ICSI involves the injection of a single sperm into an egg by the embryologist in the Assisted Reproductive Technology (ART) laboratory. A sterile glass holding pipette is used to secure the egg; an injection needle is used to pierce the egg membrane and to inject the sperm inside. ICSI is useful in other clinical scenarios besides male factor infertility (i.e. low egg number, chronic unexplained infertility) because the fertilization rate for those eggs is increased.
Preimplantation Genetic Screening (PGS) refers to an IVF laboratory technique in which a few cells are removed from the outside of the embryo(s) and are then examined to determine if they have a normal number of chromosomes. Preimplantation Genetic Diagnosis (PGD) uses the same biopsy technique as PGS but is used in situations in which a patient has a known genetic disease, or is a carrier for a disease, and the embryos are analyzed so that only unaffected embryos are transferred into the uterus. Embryos that are free of selected genetic diseases or that possess the normal number of chromosomes can be selected from a group of embryos for subsequent transfer.