ICSI (IntraCytoplasmic Sperm Injection)
ICSI revolutionized the treatment of male factor infertility.
Male factor infertility can be caused by various factors, such as mechanical or congenital blockage of the tubes which transport the sperm thereby preventing their release, inadequate sperm function due to chromosomal disorders, hormonal factors and environmental factors. In certain cases, the cause of the problem remains unknown.
ICSI can also be used in conjunction with IVF when the patient has history of failed fertilization in previous conventional IVF cycle, or when the quality of the sperm is considered to be too poor for a successful fertilization with conventional IVF.
ICSI and conventional IVF both share the same protocol for ovarian stimulation, follicular monitoring and egg collection. The sperm is prepared on the same day of egg collection regardless it is a fresh or frozen semen sample, and in same cases it involves surgically extracted sperm, such as MESA, PESA, TESA or testicular biopsy.
ICSI is a technique allowing microinjection of a single sperm into the egg. The embryologist selects a single live sperm, immobilizes it before injects it directly into a healthy mature egg using a fine pipette. The injected eggs are examined 16 – 18 hours later for evidence of fertilization. The normally fertilized eggs are cultured and monitored until the day of transfer. The day of embryo transferred can be 2, 3, 4 or 5 days after the injection and only the best embryos (usually 3 embryos) will be transferred.
Success Rates (Pregnancy Rates) with ICSI:
As ICSI bypasses the zona pellucida (egg shell) and deposits the sperm directly into the egg, ICSI results in higher fertilization rate and more embryos available for transfer than conventional IVF. In general, the success rate for ICSI is as good as or even better than conventional IVF.
Risk with ICSI:
There are concerns that ICSI is a rather invasive and new technology, it may have additional risks associated with it. In March 1999, a retrospective study involving 123 babies born in United Kingdom following ICSI was published in British Medical Journal. In this study, no increase in major congenital malformation in these babies was observed when compared to the normal population.
Another risk in this treatment is multiple pregnancies. It not only causes social and financial complications but is also associated with higher rates of pregnancy loss and lower birth weight babies. Other mild risks are infection and general anesthesia related complications.