Intracytoplasmic sperm injection (ICSI) refers to a technique in which a single sperm is injected directly into the cytoplasm of a mature oocyte. This procedure is performed as part of an in vitro fertilization (IVF) cycle, and provides an effective method for assisting fertilization in men with suboptimal semen parameters or who experienced no or low fertilization rates after conventional IVF.
This technique has consistently demonstrated higher fertilization rates and produced more embryos with higher implantation rates.
The indications for use of ICSI in conjunction with IVF have been Fertilization rates of up to 80 percent and clinical pregnancy rates of up to 45 percent are observed with ICSI, thus reducing the use of adoption or donor sperm insemination in couples with male infertility



ICSI is indicated for treatment of male factor infertility and selected types of female infertility, such as some morphologic anomalies of oocytes, limited quantities of oocytes, and anomalies of the zona pellucid. It is used in couples with previous poor fertilization or previous failed IVF cycles


ICSI is indicated for male factor infertility when success with standard IVF regimens is considered unlikely because of :


  • Less than 2 million motile spermatozoa per ejaculate
  • Antisperm antibodies thought to be causing infertility
  • Prior or repeated fertilization failure with standard IVF protocols
  • Frozen sperm limited in number and quality
  • Obstruction of the male reproductive tract not amenable to repair
  • Abnormal sperm morphology greater than 95 percent
  • Specific spermatozoa defects impairing spermatozoa-oocyte interaction

ICSI has also been successful in men with nonmosaic Klinefelter syndrome or long-standing azoospermia after chemotherapy; in these cases, spermatozoa are obtained from testicular biopsies.


Other potential indications for ICSI include:


  • HIV discordant couples
  • IVF involving, in vitro matured oocytes, or previously cryopreserved oocytes.



ICSI is unlikely to improve clinical pregnancy rates in couples with unexplained infertility or low oocyte yield and advanced maternal age.



The fertilization rate following ICSI is approximately 50 to 80 percent . Although ICSI does not guarantee fertilization, the incidence of complete fertilization failure is low and usually occurs in cycles with low oocyte yield.