Intra-cytoplasmic sperm injection (ICSI) is a relatively new but well-established procedure first performed in 1992. The procedure was developed to help male factor infertility. The procedure involves injecting a single sperm into the cytoplasm of each egg using a fine glass needle. The first ICSI baby was reported by Palermo and colleagues from Belgium in 1992. The ICSI has largely replaced the two previously developed procedures, PZD (partial zona dissection) and SUZI (subzonal insemination) because it achieves much higher fertilization rates.
The injection of immature sperm (spermatid) into the egg is not allowed in the UK because in immature sperm the nuclear maturation processes may not be complete.
For whom ICSI is advised?
There are selected groups of patients to whom intracytoplasmic sperm injection (ICSI) is recommended.
- Couples who have failed to achieve fertilization or had very poor fertilization following standard IVF treatment.
- Men with abnormal sperm parameters (e.g. low count, poor motility, high percentage of abnormal forms and high levels of antisperm antibodies in the semen) to allow a reasonable chance of success with standard IVF.
- Azoospermic (complete absence of sperm in the ejaculate) men who have their sperm surgically retrieved. This could be due to failed vasectomy reversals or congenital absence of both vas deferenses and non-obstructive azoospermia.
- When frozen sperm is limited in number and quality.
- Preimplantation diagnosis (PGD) using PCR analysis
ICSI is generally unsuccessful when used to treat fertilization failure that is primarily due to poor egg quality.