Intracytoplasmic Sperm Injection In general, ICSI has allowed couples with male factor infertility to achieve assisted reproductive technology (ART) pregnancy outcomes that are comparable with those of couples with non–male factor infertility using conventional IVF treatment (80). ICSI has been used since 1992 to increase the fertilization rate of oocytes retrieved during ART by direct injection of a live sperm into the oocyte, thereby theoretically bypassing limitations imposed by sperm motility and defects in capacitation, the acrosome reaction, and/or sperm binding the zona pellucida (81). This microsurgical procedure involves stripping the aspirated cumulus complex of all surrounding granulosa cells, followed by insertion of a single viable sperm into the cytoplasm (ooplasm) of the mature metaphase II egg (9,82). ICSI should be offered if the semen analysis shows less than 2 million motile sperm, less than 5% motility, or if surgically recovered sperm are used. Its use for abnormal morphology is more controversial (47,83). Immature or round spermatid nucleus injection (ROSNI) for ICSI is considered experimental at this time (84). Higher pregnancy rates have been noted with fresh compared to frozen specimens and with ejaculated compared to surgically retrieved sperm. Success rates are affected by the age of the female partner and oocyte quality (47). Non–male factor indications for ICSI include a history of fertilization failure with conventional IVF and the fertilization of oocytes before preimplantation genetic diagnosis (85). Other uses are described under “Unexplained Infertility.”
Risks of Intracytoplasmic Sperm Injection In skilled hands, oocyte damage with ICSI is reportedly 10% (81). However, oocyte degeneration can follow even an uncomplicated ICSI procedure, with rates as high as 30% to 50%. This is most likely a function of oocyte quality and/or patient factors rather than the ICSI process itself (82). Based on data from 5-year-old children, ICSI is associated with a higher congenital anomaly risk (4.2%) when compared with conventional IVF (typically 2% to 3%) (80). There may be an increased risk of imprinting disorders and hypospadias with ICSI (47). Reports indicate a slightly higher risk of sex chromosome abnormalities (0.8% to 1% ICSI vs. 0.2% IVF) and translocations (0.36% ICSI vs. 0.07% general population). It is unclear whether these relate to the ICSI procedure or inherent gamete defects; men with abnormal semen parameters have higher rates of sperm aneuploidy. Recent studies have not found an association with impaired intellectual or motor development among ICSI children. In the setting of specific genetic abnormalities such as Y chromosome microdeletions, abnormal karyotypes, cystic fibrosis mutations, or congenital absence of the vas deferens, genetic counseling should be offered to address the possible risk of infertility or other abnormality in the offspring (80).
Azoospermia describes the absence of spermatozoa in the ejaculate and is found in 1% of all men and up to 15% to 20% of infertile men. Causes are categorized into pretesticular (nonobstructive), testicular (nonobstructive), and posttesticular (includes obstructive and nonobstructive) etiologies, but in some cases the condition is idiopathic (47,86).