Intracytoplasmic sperm injection (ICSI) was specifically geared towards the treatment of male-factor infertility. Its arrival in the early 1990’s revolutionized the management of the poor quality semen sample. Compared with conventional insemination where a defined concentration of sperm is co-incubated with the oocyte, the ICSI procedure manually introduces a single sperm into a single oocyte. Originally thought of as an extremely crude method, the technique is advantageous in that it bypasses the physiological interactions normally necessary for sperm/egg interaction, which may be compromised in some samples. The procedure is performed in concert with an IVF cycle. The sperm injection process occurs on a specialized microscope, which permits direct visualization of the sperm, the egg and the introduction of the two gametes.
The first pregnancy at the Crozer Reproductive Endocrinology and Fertility Center resulting from ICSI occurred in 1994, only 2 years after the procedure was reported as successful in the literature. That same year at the Fertility Center twins were conceived using cryopreserved sperm from a testicular biopsy. The birth of the twins marked an event that so few programs in the world at that time experienced.
As with most innovative procedures, interest in the health of children conceived using ICSI surfaced along with its widespread use. Even though thousands of babies now have been born worldwide since its introduction, some studies show now that there is a slight increase in congenital defects following ICSI. However, some large-scale studies have refuted this evidence. Nonetheless, this evidence for increased incidence of defects may be related to the fact that pregnancy is now possible with sperm that naturally would never occur.